Picture by Nao Lizuka

Picture by Nao Lizuka

This is the third part out of five articles for this week, to help you understand and buy the right CPU.

Here’s a list of the articles in this series:

  1. 12 CPU specifications explained in plain English
  2. How to differentiate CPU models from AMD
  3. How to differentiate CPU models from Intel
  4. The Best CPU for your money: September 2009
  5. 19 of the best CPU articles

Let’s get started!

How to choose an Intel CPU: How to differentiate the models

Are you lost when you shop for a cpu? Can’t figure out the differences between all the different models? As one of my readers point it out, things were much more simple back “when there were three motherboards available and you could tell the CPU’s apart by the numbers”.

True enough, with single, dual, triple and quad-cores cpus now available, that spiced up things a bit. Intel and AMD also introduced many new products to offer more choice to the customers but unfortunately ended up confusing them more than anything. So today I’ll do my best to simplify things for you, with the AMD cpus.

Note that you’re having trouble understanding CPU specifications and terms, I invite you to read yesterday’s article, 12 CPU specifications explained in plain English.

Let’s start with an example:

You see two interesting cpus from Intel, the Celeron E3300 and the Pentium E5300, that are priced within a few dollars of each other. How can you tell which one is the best?

By the Series:

Intel offers the following series, in order of performance:

  1. Celeron
  2. Pentium
  3. Core 2 Duo
  4. Core 2 Quad
  5. Core i5
  6. Core i7

The Celeron is the budget dual-core model, featuring lower clock speed and less L2 cache. The Pentium series is a step up, offering higher clock speed and a bit more L2 cache. The Core 2 Duo series is the current high-end dual-core CPUs series from Intel. The Core 2 Quad is part of Intel lower-end quad-core processors, while Core i5 is considered more mainstream and finally, Core i7 is Intel’s most powerful series.

Which one would I pick personally if I wanted the best bang for the buck? The Core i5 series offer performance close to Core i7 series, while being priced at a much more reasonable price. Especially when you consider the cost of the motherboard, which is much less expensive for a Core i5 system than a Core i7 one.

If you go back to our example, you know would know right away that the Pentium E5300 is superior to Celeron E3300, due to its series. However, note that is only one way of evaluating which one is the best and I highly recommend to not rely on this only.

By the Model:

Just like with AMD, to know which cpu is the best, you need to understand what the various model numbers and names mean. Let’s start with the the much more common two older generations:

Core 2 Duo (Conroe and Wolfdale) and Core 2 Quad (Kentsfield and Yorkfield):

Conroe/Kentsfield: The name of the core for the first generation of Core 2 Duo/Quad.

Wolfdale/Yorkfield: The name of the core for the second generation of Core 2 Duo/Quad. At the same speed, the performance is improved by an average of 5% to 10% over the first generation.

E or Q: Dual or Quad core

First number: (1, 2, 4, 5, 6, 7, 8 and 9): Helps you identify the line-up of the cpu. Higher number usually means higher performance, due to more L2 cache, higher FSB and/or newer cpu generation.

1: Based on Conroe. 512KB L2 Cache, 800MHz FSB.

2: Based on Conroe, 1MB L2 cache. 800MHz FSB

4: Based on Conroe, 2MB L2 cache. 800MHz FSB

5: Based on Wolfdale, 2MB L2 cache. 800MHz FSB

6: Based on Conroe for dual-core, Kentsfield for quad-core, E6300 (Intel released a new E6300, with different specifications) and E6400 features 2MB L2 Cache. E6320 and E6420 feature 4MB of L2 Cache. Other dual-core feature 4MB of L2 Cache and quad-cores 8MB of L2 cache. 1066MHz FSB.
Note that the new E6300 and E6500 have 2MB of cache as well, however are based on the Wolfdale core and are clocked faster.

7: Based on Wolfdale, 3MB of L2 Cache. 1066MHz FSB

8: Based on Wolfdale for dual-core, Yorkfield for quad-core. 6MB of L2 Cache for dual-core, 4MB of L2 cache for quad-core. No, that’s not a typo. 1333MHz FSB

9: Based on Yorkfield for quad-core. 6 or 12MB of L2 Cache. 1333MHz FSB

Second number: Helps you identify how fast is the cpu compared to other models in the same line-up. For example, a E5300 is faster than a E5200.

Third and fourth number: S after the numbers: Used to identify low-power quad-core processors. xx50 model number: Used to identify quad-core processors with 12MB of L2 cache.

Here’s an example to clarify things:

Let’s compare a Core 2 Duo E6300 and a Core 2 Duo E5200.

E6300 (The first model): 1.86GHz, 2MB of L2 Cache, 1066MHz FSB, Conroe core

E5200: 2.50GHz, 2MB of L2 Cache, 800MHz FSB, Wolfdale core.

As you can see, the E6300 has the edge for the FSB, but for the rest (Frequency and core), the E5200 is superior. In the end, the E5200 is a better cpu.

Core i5 and i7:

Based on the Lynnfield (Socket 1156) and Nehalem(Socket 1366) core respectively. All models are quad-cores as I write this.

The main difference between the two are:

  1. Dual channel for Lynnfield Core i5 and core i7, triple channel for Nehalem Core i7
  2. Integrated 16 (8x,8x) PCI-Express controller on Lynnfield Core i5 and i7, none on Nehalem Core i7
  3. Core i5 does not support Hyper-threading, Core i7 does support it.
  4. 95W  TDP for Core i5, 130W  for Core i7.
  5. Socket 1156 for Lynnfield based Core i5 and Core i7, socket 1366 for Nehalem based Core i7

Higher numbers within the same line-up represents higher performance meaning that a Core i7 940 is faster than the Core i7 920.

Lynnfield and Nehalem are the most recent Intel’s generation of cpus and perform better at the same speed as a Kentsfield or Yorkfield Quad-core cpu.

Extreme edition: CPUs that are Extreme edition have their multiplier unlocked for easier overclocking.

By the Core:

In order of performance:



Used for the Celeron series, featuring one or two core and very little L2 cache. The lowest price, but also the lowest performance.


The Allendale core is basically a crippled Conroe core, featuring less L2 cache.


The Conroe core was the core used when Core 2 Duo processors where first introduced. Now phased out for the faster Wolfdale core, but still available today, the Conroe core offers very respectable performance for a dual-core processor and I have no problem recommending one if you can find a good deal on it.


The Wolfdale core is Intel’s best dual-core as I write this. Reaching speed up to 3.33GHz and having up to 6MB of L2 cache, this processor offers some serious performance.


The Kentfield core was the core used when Core 2 Quad processor where first introduced. Now phased out for the faster Yorkfield core, but still available today, the Kentfield core offers very respectable performance for a quad-core processor and I have no problem recommending one if you can find a good deal on it.


The Yorkfield replaced the Kentfield core, bringing higher performance at the same speed, along with higher frequency. Yorkfield was Intel’s fastest quad-core processor, until Nehalem was introduced that is.


Just released recently, Lynnfield is the first core to feature an integrated PCI-Express controller on its die, which is nothing short of impressive. While it is slightly slower than Nehalem due to its dual channel memory controller compared to Nehalem triple channel memory controller, Lynnfield remains an excellent choice today for someone who wants the best bang for the buck. Note that only the Core i7 series support Hyper-threading


Currently the best of the best from Intel, the Nehalem core features a triple-channel memory controller and Hyper-threading support. While it’s far from cheap, if you’re ready to invest to have nothing short of the best from Intel, this is it.

By the Frequency, TDP, socket, etc.

You can use all the other specifications that you will find on a CPU product page to make the right choice. In order to understand what all those specifications mean, so that you can choose the right Intel cpu, I invite you to read Monday’s article, 12 CPU specifications explained in plain English.


I hope that this article was useful to you and helped you learn a thing or two on Intel CPUs. I invite you to come back every day this week for more informative articles on CPUs.

I also invite you to comment and let me know your opinion on this article, ideas that you have or what you would do to improve this article.

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