Warning: These P55 motherboards will cripple your Crossfire/SLI performance

| September 14, 2009 | (122)
By Picture Perfect Pose

By Picture Perfect Pose

The release of Core i5 and i7 Lynnfield also meant the release of various motherboards with all one thing in common: The socket 1156.

If you look at the pictures of motherboards, you would believe that they are all at least equipped with two PCI-Express 16X ports. Let me explain where you might get fooled though.

What are you talking about?!

In order to cut on costs, on fourteen different motherboards, the second PCI-Express 16x is not connected via 8 lines to the PCI-Express controller of the LGA1156 processor (The first port then also being at 8x), but rather with 4 lines on the P55 controller.

On top of that, while the lines connected to the LGA1156 processor work at 5GT/s, the ones connected to the P55 only work at 2.5GT/s.

This result in a bandwidth of 1Gb/s in each direction for a PCI-Express 16x slot working at 4X with the P55 chipset, as opposed to 4GB/s when it’s working at 8x with the processor!

Needless to say, running Crossfire or SLI on a motherboard equipped with a 16x that works at 4x and is connected to the P55 chipset will cripple your performances.

Thank you to Hardware.fr (French website. I enjoy being bilingual :) ) for reporting this.

The list of motherboards to avoid if you want to use Crossfire or SLI

Here’s a list of motherboards whose second PCI-Express slot is connected at 4X with the P55 and that I urge you to avoid if you plan to build a Crossfire or SLI system:

Asrock P55 Pro
Asrock P55M Pro

Asus  P7P55D
Asus P7P55D LE

Evga P55 Micro LE

Gigabyte GA-P55M-UD2
Gigabyte GA-P55-UD3
Gigabyte GA-P55-UD3L
Gigabyte GA-P55-UD3P
Gigabyte GA-P55-UD3R
Gigabyte GA-P55-US3L

MSI P55M-GD45

The list of motherboards to go with if you want to use Crossfire or SLI

Here’s a list of motherboards that will not cripple your performance and run your video cards at 8X/8X with the LGA1156 processor controller. Note that no card needs 16X bandwidth yet, not even three Geforce GTX285 in Three-Way SLI.

They all support Crossfire and I indicate whether they support SLI or not.
I included a link to either NewEgg or Amazon when I could find them in stock at any of the two online stores.

ASRock P55 Deluxe (Two-Way SLI)
Asrock P55 Extreme (Two-Way SLI)

ASUS Maximus III Formula (Two-Way SLI)
Asus Maximus III Gene (Two-Way SLI)
ASUS P7P55 WS SuperComputer (Three-Way SLI, equipped with NF200)
ASUS P7P55D Deluxe (Two-Way SLI)
Asus P7P55D Premium (Two-Way SLI)
ASUS P7P55D PRO (Two-Way SLI)
Asus P7P55D EVO

BIOSTAR T5 XE (No SLI)
Biostar T5 XE CFX-SLI (Two-Way SLI)
BIOSTAR TPOWER i55 (Two-Way SLI)

Evga P55 (Two-Way SLI)
Evga P55 Classified 200 (Three-Way SLI)
EVGA P55 FTW (Two-Way SLI)
Evga P55 FTW 200 (Three-Way SLI)
EVGA P55 Micro (Two-Way SLI)
EVGA P55 LE 123-LF-E653-KR

GIGABYTE GA-P55M-UD4
Gigabyte GA-P55-UD4
GIGABYTE GA-P55-UD4P
GIGABYTE GA-P55-UD5
GIGABYTE GA-P55-UD6

Intel DP55KG
Intel DP55SB
Intel DP55WB
Intel DP55WG

MSI P55-GD65
MSI P55-GD80

Conclusion

If you have a blog, a website, Twitter account, Facebook, etc., I would deeply appreciate if you link to this story and spread the news. I would hate to see people buy a P55 motherboard without knowing this. I’m sure that you’ll agree ;)

I wish that manufacturers would make it more clear, but then again, it is up to the customer to double-check every information before making a purchase

As always, make sure to read all the specifications before buying any part and in the case that you have a doubt, consult with experts ;)

Category: Choose PC Parts, The Best PC Parts For Your Money

About Mathieu Bourgie: HR Founder - Computer expert with 12 years of experience in building, fixing and modifying PCs. Over the years, I’ve developed a passion for PC hardware and now I enjoy helping others build their own PCs! In April 2008, I launched Hardware Revolution and ... Read more at my about page .

  • Marcos

    Great article, Mathieu. I’m looking to build an inexpensive gaming pc with the i5 processor. I’m glad I have you on facebook.

  • Brandon

    Hm, if this is an issue, other sites will start to report the same. Lets see how this plays out.

  • BC Mack

    Are you seriously dense? You completely ignored the technical specs of the new processors. 1156-based Core i5s and i7s have a built-in 16-lane PCI-E controller, which means no matter what you choose to run in Crossfire/SLI it will run slower – dual cards at 8x each, three cards at 6x, and so on.

    You’re also completely over-hyping this by picking out all the budget boards and claiming they falsely advertise. First off, they’re not advertising anything. Go look at the pics of the packaging or the boards themselves – nowhere does it say the second slot is full 16x, and in some cases it’s clearly marked “will run in 4x mode”. Also, you completely ignore the fact that budget boards like these have been on the market for years with multiple 16x slots that run in less than 16x mode – they just had a Socket 775 or AM2.

    I’d say it’s clear that you need to sit down and learn something about new tech when it comes to market before you start telling people not to buy something. Or, at the very least, don’t even bother looking at products priced for budget gamers/enthusiasts.

    • Mathieu

      BC Mark,

      You make me wonder if you read the whole article.

      I’m well aware that the processors based on the LGA1156 socket are equipped with a 16-lane PCI-E controller, that is something that was made very clear by Intel.

      Where do you get that it will run slower at 8X? I included this link from HotHardware in the article: http://hothardware.com/Articles/Asus-P6T6-WS-Revolution-Core-i7-Motherboard/?page=10

      Where they benchmark three Geforce GTX 285 in Three-Way SLI and they compare 16x/16x/16x vs 16x/8x/8x and they found NO difference in performance what so ever.

      Obviously, we are talking about PCI-Express 2.0 here, not 1.0.

      Regarding advertising. No where in this article do I state that motherboards manufacturers are doing false advertisement.

      I simply say that if someone was not to pay attention to specs when buying a motherboard, they might not get the best performance out of Crossfire or SLI.

      I also say at the end that I wish that it made more clear, like with Intel who used shorter PCI-Express slots length on their motherboards to show that they are not 16X slots.

      As for ignoring that budget boards have been like this for years, I simply don’t agree with you, as this is a different situation in my opinion.

      I know quite a few persons who expected to see 8X/8X on any motherboard equipped with two slots, due the design of the LGA1156 processors. Clearly, this is NOT the case and this is why I’m reporting it.

      Besides, the “4X mode” is much slower than a 4X connected to the LGA1156 processor is, as I pointed in my article.

      My goal here was simply make sure that this is clear for anyone who intends to buy a P55 motherboard. There’s a pretty wide audience, with a varying levels of knowledge. I believe that this article was useful to many. You have the right to not agree though.

  • Kurt

    Great article. Even though some misunderstood what you were saying (and quite frankly, just want to pretend they are smarter than you), I think you were writing this for people who may be in the market but don’t know what specs are important so they may end up with something that will impose limits on their hardware.

    Since I have been looking at these boards myself, I agree that not all manufacturers are as outright about the limitations as they should be. They will advertise 3-way SLI but unless you get into the specs and see the 8x, 4x, 4x you would never know that they are talking about reduced throughput.

    My question for you is… given the choices available, which is the best board for Crossfire (16x, 16x) with two ATI video cards and an LGA1156 with i7 processor? I don’t want to give up performance and I want lots of retro-tech included (I just got over AGP). Also looking at a price cap of around $300.00.

    Thanks!

    • Mathieu

      Kurt,

      You’re right on regarding who I targeted with this article.

      The problem I believe is not so much that manufacturers are not outright about limitations, but rather that many people believe that if you have two PCI-Express slots and that the box says “Crossfire supported”, they have everything that they need. Most people won’t dig deeper due to their lack of knowledge. Then again, there isn’t that much information available either.

      Regarding the best board for Crossfire. First of all, there are no 16x, 16x boards, as the processor has a 16 lanes PCI-Express controllers, so that’s 8x, 8x for two cards in Crossfire.

      That said, my personnal choice would the ASUS P7P55D Pro which you can find here: http://bit.ly/3Hzj2w

      It features a very good layout, as you can actually use a PCI slot if you have a PCI controller card or sound card, two PCI-Express 1x slots for additional add-on cards. On the back, you have two PS/2 ports for older mouse and keyboards, 8 USB ports, e-SATA, Firewire and RJ-45 (LAN), along with Coaxial and Optical S/PDIF out and finally 8 channels audio.

      Also good to know, you have a IDE and a floppy port on this motherboard, two older ports that are starting to disappear on some motherboards.

      Best of all, it’s priced at $169.99!

      I believe that it offers a very nice balance of features, a great layout and ASUS is the most trusted brand by readers here on Hardware Revolution, for a good reason.

      Hope that helps you out.

  • Woody

    There is no deception here. The specs for these systems are published. These motherboards are designed for budget to mid range systems at best so their performance is more in line with what the consumer would need for the price they want. Dropping two or three very high end and expensive graphics cards into an LGA 1156 based motherboard would be silly so there is no need for more bandwidth. That is why Intel has the LGA 1366 systems. For mid range graphics cards there is more than enough bandwidth for SLI or crossfire which is what these boards are designed for.

    In my opinion the original article is misleading and indicates a lack of technical understanding on the part of the author. Sorry about that but you should do your research before you cut loose online.

  • Jay

    BIOSTAR T5 XE does not support 8x/8x, says the specs.

    Thanks for the article though, quick resource to find CF/SLI boards.

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    This result in a bandwidth of 1Gb/s in each direction for a PCI-Express 16x slot working at 4X with the P55 chipset, as opposed to 4GB/s when it’s working at 8x with the processor!

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    Here’s a list of motherboards that will not cripple your performance and run your video cards at 8X/8X with the LGA1156 processor controller. Note that no card

  • http://www.galaxyhandbags.com/ Louis Vuitton Handbags

    Glad to know you, I like your article, I will focus on your blog all the time.

  • sam

    is the p7p55d motherboard that supports crossfire really such a bad choice for for future crossfiring. i understant that instead of getting 8x 8x i would get 8x 4x. is that like only getting half of the peformance that i am paying for for the other card runnibg at 4x or am i understanding the concep
    t wrong.

  • sam

    is the p7p55d motherboard that supports crossfire really such a bad choice for for future crossfiring. i understant that instead of getting 8x 8x i would get 8x 4x. is that like only getting half of the peformance that i am paying for for the other card runnibg at 4x or am i understanding the concept wrong.

    • http://www.hardware-revolution.com/ MathieuB

      Sam,

      Yes, any of the motherboards that are set up in such a way are to avoid for Crossfire, especially in the future.

      The lines connected to the LGA1156 processor work at 5GT/s while the ones connected to the P55 only work at 2.5GT/s. Meaning that instead of 8x 8x, you would get more like 8x 2x.

      Anything under 8x will bottleneck a current generation video card.

      Hope that helps.

  • RogerWilcoZA

    Hey Mathieu, great article. I'm no techie so apologies to all if this is a silly question.

    I'm about to buy a new system using the Asus P7P55D board and a single HD 5850 card. However I'm also going to be purchasing a Asus Xonar soundcard which will go into the unused 1x PCI express slot. Would this affect the bandwidth of my video card?

  • RogerWilcoZA

    Hey Mathieu, great article. I'm no techie so apologies to all if this is a silly question.

    I'm about to buy a new system using the Asus P7P55D board and a single HD 5850 card. However I'm also going to be purchasing a Asus Xonar soundcard which will go into the unused 1x PCI express slot. Would this affect the bandwidth of my video card?

    • http://www.hardware-revolution.com/ MathieuB

      Hey Roger,

      No problem about not being a techie, this blog is open to everyone, beginners or experts. After all, we all start somewhere.

      The video card is linked directly to the CPU, while the sound card will be linked to the chipset, so to answer your question, no this will not affect the bandwidth of your video card.

      Hope that helps.

      • RogerWilcoZA

        awesome nice one

  • http://feeds2.feedburner.com/hardware-revolution MathieuB

    Sam,

    Yes, any of the motherboards that are set up in such a way are to avoid for Crossfire, especially in the future.

    The lines connected to the LGA1156 processor work at 5GT/s while the ones connected to the P55 only work at 2.5GT/s. Meaning that instead of 8x 8x, you would get more like 8x 2x.

    Anything under 8x will bottleneck a current generation video card.

    Hope that helps.

  • http://feeds2.feedburner.com/hardware-revolution MathieuB

    Hey Roger,

    No problem about not being a techie, this blog is open to everyone, beginners or experts. After all, we all start somewhere.

    The video card is linked directly to the CPU, while the sound card will be linked to the chipset, so to answer your question, no this will not affect the bandwidth of your video card.

    Hope that helps.

  • CJ

    DFI p55 mobo runs at 16x or 8x/8x or 8x/8x/4x. It will not cripple your sli setup. Take DFI's name out of that list.

  • CJ

    DFI p55 mobo runs at 16x or 8x/8x or 8x/8x/4x. It will not cripple your sli setup. Take DFI's name out of that list.

    • http://www.hardware-revolution.com/ MathieuB

      After verification, the DFI Lanparty DK P55-T3eH9 runs either at 16x/4x/none or 8x/4x/8x. Thanks for pointing it out, it has been taken off the list.

  • http://feeds2.feedburner.com/hardware-revolution MathieuB

    After verification, the DFI Lanparty DK P55-T3eH9 runs either at 16x/4x/none or 8x/4x/8x. Thanks for pointing it out, it has been taken off the list.

  • Carrot

    Thank you – it's a shame, I bought a pre-built iBuypower PC and it didn't say the chipset mobo it came with was this model. So I'm stuck with a setup I'd like to do SLI on, that says is SLI ready, when in fact, it's not.

    Guess I need to look at upgrading… grr. So frustrating.

  • Rayden47

    Mathieu,

    Thanx for all the hard work u 've put to help us guys. I've done much research on motherboards, cpu, graphics cards and monitors, but never came through this blog until today. And I think u are actually the person we can rely on. Keep up the good work.

    I m planning to build a gaming pc within $1500 (Rs.60,000 INR). So please suggest me a configuration. My priorities are Intel i7 860, ASUS/MSI P55 MoBo supporting Crossfire and SLI, and Good 22″ LCD monitor for gaming. And please tell me What do you think about Intel i7 860 CPU?

  • Rayden47

    Mathieu,

    Thanx for all the hard work u 've put to help us guys. I've done much research on motherboards, cpu, graphics cards and monitors, but never came through this blog until today. And I think u are actually the person we can rely on. Keep up the good work.

    I m planning to build a gaming pc within $1500 (Rs.60,000 INR). So please suggest me a configuration. My priorities are Intel i7 860, ASUS/MSI P55 MoBo supporting Crossfire and SLI, and Good 22″ LCD monitor for gaming. And please tell me What do you think about Intel i7 860 CPU?

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  • Pick

    Asrock P55 Extreme is also a 16x/4x performance crippler, you should take it off your list. Anyways, good lookin’! :)

    Pick

    • Pick

      Sorry, I was mistaken there – seems the Asrock P55 Extreme is indeed an 8x/8x mobo. Please delete my posts, if possible…

  • Pick

    Asrock P55 Extreme is also a 16x/4x performance crippler, you should take it off your list. Anyways, good lookin'! :)

    Pick

  • Pick

    Sorry, I was mistaken there – seems the Asrock P55 Extreme is indeed an 8x/8x mobo. Please delete my posts, if possible…

  • George

    Good article I found out the hard way on my EVGA P55 LE wondering why my crossfire benchmarks were way lower than the benchmarks online. I opened up gpu-z to find slot 2 was running at 4x(16x/4x) and not 8x/8x like I though it would when I bought it. I'm now getting a new motherboard.

  • George

    Good article I found out the hard way on my EVGA P55 LE wondering why my crossfire benchmarks were way lower than the benchmarks online. I opened up gpu-z to find slot 2 was running at 4x(16x/4x) and not 8x/8x like I though it would when I bought it. I'm now getting a new motherboard.

  • th3r3turn

    Does this need a update on here? the Asus P7P55D EVO site tells me that

    http://www.asus.com/product.aspx?P_ID=YhNWZrOT1…

    2 x PCIe 2.0 x16 (single at x16 or dual at x8/x8 mode)
    1 x PCI Express 2.0 x16 slots (at x4 mode, 2.5GT/s)

    so that board should be under the list of Boards to use for SLi/Crossfire!

    • Leetness

      Hello,
      Here you say the EVGA P55 LE is okay for crossfire,
      But on their site, it says it has 1 x16 and 1×4 slot…
      Can I still run Crossfire with this motherboard?

  • th3r3turn

    Does this need a update on here? the Asus P7P55D EVO site tells me that

    http://www.asus.com/product.aspx?P_ID=YhNWZrOT1…

    2 x PCIe 2.0 x16 (single at x16 or dual at x8/x8 mode)
    1 x PCI Express 2.0 x16 slots (at x4 mode, 2.5GT/s)

    so that board should be under the list of Boards to use for SLi/Crossfire!

    • http://www.hardware-revolution.com/ MathieuB

      Thanks for pointing it out, the list was updated.

      • th3r3turn

        nice to see this is being updated! i use it for people that are lookin @ getting into i5/i7 boards!

  • LuBu

    I have been looking into an EVGA P55 LE for a new build that might include another ATi card for xfire in the near future. According to the EVGA website, and a review at Hardware Secrets (http://www.hardwaresecrets.com/article/804/1) both physical PCI-E 2.0 x16 slots will run at (16x, 1x) or (8x, 8x) electrically to the CPU controller.

    The P55 LE, however, is on your list as running the second PCI-E 2.0 slot at 4x electrically through the chipset with a second video card installed. Something is incorrect in one of the reviews.

    Can you direct me to the review where the EVGA P55 LE board is running the second card at 4x electrically, as you claimed. It doesn't appear as a reviewed board on the link to the French site.

    Cheers.

  • http://www.hardware-revolution.com/ MathieuB

    Thanks for pointing it out, the list was updated.

  • http://www.hardware-revolution.com/ MathieuB

    The list was based off the information from the French site, which would seem, was based on early information. The EVGA P55 LE can indeed run at 8x,8x. Thanks for pointing it out, the list was updated.

  • LuBu

    I have been looking into an EVGA P55 LE for a new build that might include another ATi card for xfire in the near future. According to the EVGA website, and a review at Hardware Secrets (http://www.hardwaresecrets.com/article/804/1) both physical PCI-E 2.0 x16 slots will run at (16x, 1x) or (8x, 8x) electrically to the CPU controller.

    The P55 LE, however, is on your list as running the second PCI-E 2.0 slot at 4x electrically through the chipset with a second video card installed. Something is incorrect in one of the reviews.

    Can you direct me to the review where the EVGA P55 LE board is running the second card at 4x electrically, as you claimed. It doesn't appear as a reviewed board on the link to the French site.

    Cheers.

    • http://www.hardware-revolution.com/ MathieuB

      The list was based off the information from the French site, which would seem, was based on early information. The EVGA P55 LE can indeed run at 8x,8x. Thanks for pointing it out, the list was updated.

      • LuBu

        Sorry about this MathieuB, but after speaking directly to EVGA support about the arrangements of the PCI-E lanes of the P55 LE EVGA confirmed to me that the board does NOT switch to x8, x8, but remains x16,x4 (with the x4 going through the chipset and thus running the second card effectively at x2).

        It appears that the Hardware Secrets review is in fact incorrect. The board does not switch to x8,x8, and the 'specs at a glance' on the EVGA website for the P55 LE is also incorrect.

        A part of me cannot help but wonder if these errors were accidentally-on-purpose…

  • th3r3turn

    nice to see this is being updated! i use it for people that are lookin @ getting into i5/i7 boards!

  • LuBu

    Sorry about this MathieuB, but after speaking directly to EVGA support about the arrangements of the PCI-E lanes of the P55 LE EVGA confirmed to me that the board does NOT switch to x8, x8, but remains x16,x4 (with the x4 going through the chipset and thus running the second card effectively at x2).

    It appears that the Hardware Secrets review is in fact incorrect. The board does not switch to x8,x8, and the 'specs at a glance' on the EVGA website for the P55 LE is also incorrect.

    A part of me cannot help but wonder if these errors were accidentally-on-purpose…

  • steve

    I linked to your article in my article.

    ATi 5770: PCIe x16 vx x8
    http://www.thetomorrowtimes.com/2010/03/ati-rad…

    conclusion: Typically, expect only 2 or 3 percentage points lost from using PCIe x8 (aka, crossfire on the P55)

    • http://www.hardware-revolution.com/ MathieuB

      Steve,

      First of all, thanks for the link, it’s appreciated.

      Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn’t any better than 16x/8x/8x. This is why I don’t recommend the X58 platform unless you are an extreme overclocker.

      I’m curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

    • http://www.hardware-revolution.com/ MathieuB

      Steve,

      First of all, thanks for the link, it’s appreciated.

      Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn’t any better than 16x/8x/8x. This is why I don’t recommend the X58 platform unless you are an extreme overclocker.

      I’m curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

    • http://www.hardware-revolution.com/ MathieuB

      Steve,

      First of all, thanks for the link, it’s appreciated.

      Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn’t any better than 16x/8x/8x. This is why I don’t recommend the X58 platform unless you are an extreme overclocker.

      I’m curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

    • http://www.hardware-revolution.com/ MathieuB

      Steve,

      First of all, thanks for the link, it’s appreciated.

      Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn’t any better than 16x/8x/8x. This is why I don’t recommend the X58 platform unless you are an extreme overclocker.

      I’m curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

    • http://www.hardware-revolution.com/ MathieuB

      Steve,

      First of all, thanks for the link, it’s appreciated.

      Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn’t any better than 16x/8x/8x. This is why I don’t recommend the X58 platform unless you are an extreme overclocker.

      I’m curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

    • http://www.hardware-revolution.com/ MathieuB

      Steve,

      First of all, thanks for the link, it's appreciated.

      Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn't any better than 16x/8x/8x. This is why I don't recommend the X58 platform unless you are an extreme overclocker.

      I'm curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

      • Leetness

        Hello,
        Here you say the EVGA P55 LE is okay for crossfire,
        But on their site, it says it has 1 x16 and 1×4 slot…
        Can I still run Crossfire with this motherboard?

        • http://www.hardware-revolution.com/ MathieuB

          I can confirm that the EVGA P55 LE has two PCI-Express 16x 2.0 slots, that will run at 8x/8x in Crossfire, so yes, you can run Crossfire on that motherboard.

        • http://www.hardware-revolution.com/ MathieuB

          I can confirm that the EVGA P55 LE has two PCI-Express 16x 2.0 slots, that will run at 8x/8x in Crossfire, so yes, you can run Crossfire on that motherboard.

  • http://www.hardware-revolution.com/ MathieuB

    Steve,

    First of all, thanks for the link, it's appreciated.

    Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn't any better than 16x/8x/8x. This is why I don't recommend the X58 platform unless you are an extreme overclocker.

    I'm curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

    • http://www.hardware-revolution.com/ MathieuB

      I can confirm that the EVGA P55 LE has two PCI-Express 16x 2.0 slots, that will run at 8x/8x in Crossfire, so yes, you can run Crossfire on that motherboard.

  • http://www.hardware-revolution.com/ MathieuB

    Steve,

    First of all, thanks for the link, it's appreciated.

    Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn't any better than 16x/8x/8x. This is why I don't recommend the X58 platform unless you are an extreme overclocker.

    I'm curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

    • Markus

      Well I really wish I read this before I purchased this board because now i've purchased two 5770's and the performence on this board is as you stated, not optimal. I feel that ASUS has ripped me off. Why would they even put crossfire on the box of this board!!!

  • http://www.hardware-revolution.com/ MathieuB

    Steve,

    First of all, thanks for the link, it's appreciated.

    Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn't any better than 16x/8x/8x. This is why I don't recommend the X58 platform unless you are an extreme overclocker.

    I'm curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

  • http://www.hardware-revolution.com/ MathieuB

    Steve,

    First of all, thanks for the link, it's appreciated.

    Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn't any better than 16x/8x/8x. This is why I don't recommend the X58 platform unless you are an extreme overclocker.

    I'm curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

  • http://www.hardware-revolution.com/ MathieuB

    Steve,

    First of all, thanks for the link, it's appreciated.

    Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn't any better than 16x/8x/8x. This is why I don't recommend the X58 platform unless you are an extreme overclocker.

    I'm curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

    • Leetness

      Hello,
      Here you say the EVGA P55 LE is okay for crossfire,
      But on their site, it says it has 1 x16 and 1×4 slot…
      Can I still run Crossfire with this motherboard?

  • http://www.hardware-revolution.com/ MathieuB

    Steve,

    First of all, thanks for the link, it's appreciated.

    Indeed, 8x/8x is perfectly fine for Crossfire. I actually recall reading an article where they had three Geforce GTX285 in Three-Way SLI and 16x/16x/16x or 16x/16x/8x wasn't any better than 16x/8x/8x. This is why I don't recommend the X58 platform unless you are an extreme overclocker.

    I'm curious to see how two Radeon 5870 or two of the new Geforce GTX380 would do in 16x/16x vs 8x/8x though.

  • Leetness

    Hello,
    Here you say the EVGA P55 LE is okay for crossfire,
    But on their site, it says it has 1 x16 and 1×4 slot…
    Can I still run Crossfire with this motherboard?

  • http://www.hardware-revolution.com/ MathieuB

    It's all about marketing. Technically, your motherboard does support Crossfire, so they are not lying to you. Obviously, it's deceptive marketing, as you won't get the performance boost that you want. I wish every manufacturer would be honest and not let marketing go too far sometimes.

  • Markus

    Well I really wish I read this before I purchased this board because now i've purchased two 5770's and the performence on this board is as you stated, not optimal. I feel that ASUS has ripped me off. Why would they even put crossfire on the box of this board!!!

    • http://www.hardware-revolution.com/ MathieuB

      It's all about marketing. Technically, your motherboard does support Crossfire, so they are not lying to you. Obviously, it's deceptive marketing, as you won't get the performance boost that you want. I wish every manufacturer would be honest and not let marketing go too far sometimes.

  • Xt

    Hi, see http://www.evga.com/products/moreinfo.asp?pn=12…

    EVGA P55 LE can only do Crossfire at 16x/4x configuration. Please update your data. The Hardware Secrets review seems to be inaccurate.

  • Xt

    Hi, see http://www.evga.com/products/moreinfo.asp?pn=12…

    EVGA P55 LE can only do Crossfire at 16x/4x configuration. Please update your data. The Hardware Secrets review seems to be inaccurate.

  • Viral

    Ok read the article, and was quite happy to have the advice. Helps me a lot.

    So I chose the EVGA P55 SLI Mobo (http://www.tigerdirect.com/applications/searcht…) for my first computer build, and I was wondering about how to choose the memory? I know I need DDR3, but do i need Daul Channal? Does daul channel need two sticks to work? I was going to go, and get 1 stick of 4 gb Ram, but should I get 2 sticks for better performance right of the bat? Any help would be greatly appreciated! If you could just suggest some Ram sticks for the mobo that would be great.

  • Dualxt

    Stick with dual channel memory because it is more future proof. It will either be hard to find another single 4gb or it would be quite expensive in the future. Second, dual channel memory overclocks much better than single channel memory if you plan on overclocking your cpu. Third, dual channel does give you a performance boost over a single stick since you are not putting all the “work” on that one slot. With dual channel, “work” is shared between two slots. As for the memory, I suggest G.Skill, OCZ, Patriot, Crucial, or Corsair that operate at voltages of 1.65V or less. Do not buy memory that's rated more than 1.65V or you might burn out the memory controller on your cpu.

  • Viral

    Ok read the article, and was quite happy to have the advice. Helps me a lot.

    So I chose the EVGA P55 SLI Mobo (http://www.tigerdirect.com/applications/searcht…) for my first computer build, and I was wondering about how to choose the memory? I know I need DDR3, but do i need Daul Channal? Does daul channel need two sticks to work? I was going to go, and get 1 stick of 4 gb Ram, but should I get 2 sticks for better performance right of the bat? Any help would be greatly appreciated! If you could just suggest some Ram sticks for the mobo that would be great.

    • Dualxt

      Stick with dual channel memory because it is more future proof. It will either be hard to find another single 4gb or it would be quite expensive in the future. Second, dual channel memory overclocks much better than single channel memory if you plan on overclocking your cpu. Third, dual channel does give you a performance boost over a single stick since you are not putting all the “work” on that one slot. With dual channel, “work” is shared between two slots. As for the memory, I suggest G.Skill, OCZ, Patriot, Crucial, or Corsair that operate at voltages of 1.65V or less. Do not buy memory that's rated more than 1.65V or you might burn out the memory controller on your cpu.

  • Justin

    hey so wat would GIGABYTE GA-P55M-UD4
    be would it be x16 x8 just question building my first comp with GTX 460 SLI

    • http://www.hardware-revolution.com/ MathieuB

      Justin,

      The GIGABYTE GA-P55M-UD4 would run at 8x/8x, which is fine for two GTX 460 in SLI.

      Take care,
      Mathieu

  • Spencer

    Tahnks for this! I saw it and was like uh oh, till I read on to find my mainboard is in the list of “good ones”. Thank you very much for this!

  • Dingus

    Hi, Just got a GA-P55A-UD4 and can confirm that both slots run at 8x8x with 2 5850's. However i alos read somewhere that if you enable the usb 3 and sata 3 in the bois it will disable the 2nd slot as it uses the pci-e lanes to run. Can you or someone else confirm if this is true as gigabyte websit doesnt state any of this.

    • http://www.hardware-revolution.com/ MathieuB

      Dingus,

      That would be correct, Gigabyte states this:
      “* When set Turbo SATA3 / USB3.0 (Marvell 9128 /NEC USB 3.0 Controller) to enable in BIOS setup, 1st PCIex16 slot will run at x8 bandwidth and 2nd PCIex16 slot will be disabled.”

      If you want USB 3.0 and SATA 6.0Gb/s while using Crossfire, the ASUS P7P55D-E Pro (http://www.newegg.com/Product/Product.aspx?Item=N82E16813131621) is what I recommend. It has a specific PLX chip to handle the USB 3.0 and SATA 6.0Gb/s bandwidth requirements.

      Take care,
      Mathieu

      • Csavage75

        Dam Too late now i just forked £145 for this board. Dont think wifey would be impressed if i went and got another LOL. I suppose for the time being ill just have to live without. Not like theres loads of SATA3 and USB3 devices out there at the mo

      • LAZA_R56

        Why ASUS P7P55D-E Pro an not ASUS P7P55D-D Evo??
        What are the differences??

        • Tony

          Is the asus P7P55D-E Evo even available? I don't see it anywhere available for purchase. At any event, if you compare the two…there's only two differences between the E-Pro and E-Evo…the Evo has the dual lan and a reset cmos button on the board. Just for those two added abilities, I'm certain there's a hefty price attached for the E-Evo. So, in my opinion….Mathieu is going to recommend you something that's sensible and practical gift wrapped with proven functionality (which is the concept of this site) and it's up to you to determine what fits your needs depending on added options. Just my opinion. :)

          • Tony

            Also, I think what also needs to be pointed out is the option to add the 3.0 usb/6.0gb with the same pxl chip integrated. This may possibly break some of the limitations of other Asus boards passed up that don't automatically come with this option or correct some of the boards that are on this list…at least, as far as Asus goes.
            ASUS Model U3S6 USB 3.0 & SATA 6Gb/s Add-on card

            Compatibility:
            Maximus III Formula
            P7P55D Deluxe
            P7P55D EVO
            P7P55D PRO
            P7P55D
            P7P55D LE
            P7P55 LX
            P7P55 WS Supercomputer
            P6T Deluxe
            P6T Deluxe V2
            P6TD deluxe
            P6T SE
            Rampage II Extreme
            Rampage II Gene
            M4A79T Deluxe
            M4A785TD-V EVO
            M4A77TD PRO
            M4A79T Deluxe/U3S6
            M4A77TD PRO/U3S6
            M4A785TD-V EVO/U3S6
            P6T WS Professional
            P6T6 WS Revolution
            P6T7 WS SuperComputer

          • LAZA_R56

            Thanks for the quick reply :)

            Here in Greece there is the option to buy both cards :) with 10 Euros(13 USD) difference at the price.
            My question wasn't about to find the cheaper card but the better for me…

            My story is that I had a Gigabyte P55-US3L with a HD5770 on and yesterday I bought a second 5770… when i opened the box and saw the Crossfire cable I was sure that something wasn't right. The thing is that the two PCI slots are far away enought so the cable can't reach the two cards :(
            As far as I know there are no bigger Crossfire cables so… I found your post here, i realized that my Gigabyte mobo isn't good for SLi/Crossfire, bla bla bla…
            TY Hardware-Revolution!!! :)

          • Tony

            Woah, I hope you didn't take my comments as recommendations. I'm as much a noob as some of the people using Mathieu's builds or worse. I was simply making observations. Even with Mathieu's recommendations, I still managed to make some mistakes on my own that I regret. Such as purchasing a 520 watt supply instead of a 750 watt or better. Using Mathieu's $850 build list, I went with the Asus P7P55D-E Pro instead of the Gigabyte GA-P55A-UD3 specifically for the dual PCI Express slots for future SLI setup…..and totally forgot that I'm going to need a suitable power supply for that purpose. Also, as an after thought, I went with the Corsair H50 AFTER buying the Cooler Master Hyper 212…..so right off the top, I wasted $60 for the PSU and $30 for the PCU Cooler. So….just to recap…..don't take my advice! lol

          • http://www.hardware-revolution.com/ MathieuB

            Yeah, the Gigabyte GA-P55-US3L isn't designed with Crossfire in mind, considering the PCI-Express 16x slots layout. Looks like Gigabyte had a Nvidia card + A Physx card in mind.

          • http://www.hardware-revolution.com/ MathieuB

            Tony,

            Talk about a nifty little card that's affordable. Too bad it's only compatible with some ASUS motherboards, or so say ASUS anyway.

            I might just get one for my own workstation (ASUS M4A785TD-V EVO), see if it works, seeing as I'll probably pick up one of the next generation SSDs that will be coming out soon.

            Take care,
            Mathieu

        • http://www.hardware-revolution.com/ MathieuB

          Laza_R56,

          Simple enough, the P7P55P-E Pro features USB 3.0 and SATA 6.0Gb/s, while the P7P55D Evo (No such thing as a P7P55D-D Evo) doesn't feature USB 3.0 nor Sata 6.0Gb/s.

  • A Newcomer

    Glad I saw this!
    So if I'm thinking of buying an Intel DP55SB to run 2 Radeon HD 5770s in CrossFire, that's fine?
    The mobo is listed as having “1 PCI Express 2.0 x16 , 2 PCI Express 2.0 x1″ as expansion slots, and that's alright?

    Sorry if this seems retarded but I'm still on the learning curve!

    • Andrew J

      It's not possible to run two Radeon HD 5770s in CrossFire on that board, you need two PCI-e x16 slots – you physically can not fit more than one video card on to that board.

      I recommend the ASUS P7P55D (http://www.newegg.com/Product/Product.aspx?Item=N82E16813131405) as it's slightly cheaper but you can use two video cards with no problems, and it has pretty much all the same features, though you may want to wait for MathieuB's response.

  • 0mifundum0

    What about the MSI P55A-GD65 vs. the ASUS P7P55D-E Pro in combination with the i5 760? MathieuB, does the MSI do the same tricks as the ASUS you recommend?

    • http://www.hardware-revolution.com/ MathieuB

      According to one customer review of the MSI P55A-GD65, it would appear to support USB 3.0/SATA 6.0Gb/s at full speed, with Crossfire at the same time, just like the ASUS P7P55D-E Pro.

      Hope this helps,
      Mathieu

  • Caido

    Hey Mathieu,

    I wish I had found your site sooner! I am a “techy” like yourself, though not as dedicated. My lats job was actually a “computer engineer” and for the last year or two I've only had time for school and working on computers in a corporate setting. Now I have some free time and am building a small foot print, very well balanced performance htpc/gaming/workstation.

    Basically, I was playing catch up by researching all of the latest components when I came across a recommendation to your site. After nearly completing my rig blueprints and doing every last bit of research, I find you've done all the work for me. Great site.

    On Topic:

    For those who have a slightly larger budget or find a good deal on one, would you recommend the X58? From what i've gathered, all in all a superior board especially for intensive purposes. One review says its geared more for high-end workstations, but I assume there would be some benefit on a mid-range rig, especially if using a six core processor.

    For me, just by being attentive to others' reviews and comments, I learned not to expect to be able to use multi-GPU on boards simply because they say they have SLI or CF. I'd also advise double checking the physical PCI/e layout especially on mATX boards, as they have very limited space and even if able to use 16x/16x PCIe, may block any other slots you were intending to use, or occasionally can even be too close together.

  • KenaGT

    Ok guys wlll this is what i’ve found about this….i have Gigabyte P55A-UD3 mobo….and i wanted to go Crossfire …first what i have tested is that i put my 5870 into x4 PCIE slot…and i notices a little FPS dro but not as bad as i thought….with proporition i figured this:

    with mine x16 slot i have 100% performance of mine car but with x4 slot i have 89,5% of mine card so if i put another card in second slot performance loss would be10.5% so that id not that bad for x4 slot i thought that performance lost would be >25% of 100% in the first slot….so if i wanted to go CF i would lost about 10,5% of 200%(not true 200% but in theory it is 200%) preformance….that is mine little test….so i dont have to selll mine Mobo and buy one with x8 x8 in SLI or CF….because this 10% doesnt mean that much….

  • KenaGT

    and i also found this:

    http://www.techpowerup.com/reviews/AMD/HD_5870_PCI-Express_Scaling/1.html

    So it isn’t that bad but it depend on what you want if you don care about ~10% drop in performance ok, but if you do care so go with one of x8,x8 mobo’s adn that’s it….i personallly don’t care why? if i am budget contrained and if i already bought this motherboard why should i sell this one because 10% performance drop?….but this is mine opinion everyone has its own opinion which is different from mine and i respect that also….thanks

  • KenaGT

    jup and i forgot to say something…i tested this mobo with x4,x4 CF setup and performance loss was about 15-20% depending on application and game….more bandwidth more performance loss….

  • Jeff

    Almost purchased a Gigabyte GA-P55-UD3, with possible Sli setup (gtx 460) for future use, until reading this article and realizing it wouldn’t do 8x/8x. I was aware of the limitations of the technology (p55) but had just completely forgot. Thanks for the heads up :)

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  • Bryant

    Sorry guys, can i ask a question, I have a Gigabyte P55-UD3 with 1x GTX460 now, so actually can my motherboard supports SLI or no?

    I saw Crossfire on the Box but not SLI, so is it still possible?

  • Bryant

    Sorry, its Gigabyte P55A-UD3 :)

    • http://www.hardware-revolution.com/ MathieuB

      Nope, SLI isn’t supported on that motherboard. Your best choice would be to sell your card and to upgrade to say, a Geforce GTX 570, to see a good improvement.

      • Bryant

        I see, thanks alot for the reply. I guess I did bought the wrong motherboard afterall :(

  • Naveen krishali

    hi, Mathieu, a nice article, but i needed info for SLI capable (8X 8X) for i5-2400. Cud u plz help me out. i m getting much confused on reviews… Thanx

  • Jayke

    Has been shown in many website charts that the performance penalty is less than ~6% with 5870 CF @4x board. 2/3 fps.

    Now that doesn’t mean a GTX 580 SLI won’t suffer a larger penalty, but the major bottle neck on older “1156″ sockets will likely the be the CPU on ~1080P resolutions with such a setup.

    Imho 2500k + 1155 4x boards are fine for 6950 CF.

    Imho this is a non issue, consumers with enough money for GTX 570+ SLI setups will buy 8x 8x or higher end 40x pcie lane boards.

    When lack of pcie lanes becomes issue for powerful sli/cf setups, the pc industry will have other solutions or moved to pcie 3.

    Appreciate your trying to keep consumers informed, but really only causing confusion.

  • Mehoppe920

    Had the Gigabyte P55-USB3 with 2 Plait Sonic Platinum 570′s Ran fine but the Asus P7P55D-E Pro runs better bench marks in the FurMark tests.

  • http://pulse.yahoo.com/_S7W6DAFGL4E33VK3FU6PRQMOQM Philip Bowyer

    I just bought the Asus Maximus III Gene as recomended by this review and it does NOT support 2 GTX 460 graphics cards. they require 2x 16x bandwidth slots and the Asus Maximus III Gene only has 1x 16x slot (and 1 8x slot)… your info is out of date! thankyou for nothing

  • Gg

    SLI can be done on almost any motherboard with 2 PCI-E slots (not taking the x1 slots into consideration). The trick is in the software used, google for “Hyper-SLI” . Performance is good, although sometimes not optimal, but way better than single card.

  • Delticsarebest

    MSI P55-GD65
    is allso no good in crossfire

  • envoy

    If I am running a 8x/8x crossfire setup on a P7P55D Evo, will an additional PCIe card [network adapter] cripple the crossfire performance??

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  • Carrot

    Thank you – it's a shame, I bought a pre-built iBuypower PC and it didn't say the chipset mobo it came with was this model. So I'm stuck with a setup I'd like to do SLI on, that says is SLI ready, when in fact, it's not.

    Guess I need to look at upgrading… grr. So frustrating.