Intel Westmere 32nm Launch & Clarkdale Core i5-661 CPU Review

by MAC     |     January 3, 2010

Clarkdale - Pentium G6000 Series, Core i3-500 Series, Core i5-600 Series

Unlike with the Lynnfield launch where chips and motherboards were being sold weeks before the media embargo ended, Clarkdale has been kept relatively under wraps. Yes, engineering samples found their way into the hands of overclockers and a lot of information has already been leaked, but at least now we can finally reveal (or least confirm) everything you have wanted to know about the new Clarkdale processor family, consisting of the Pentium G6000 series, the i3-500 series, and the i5-600 series.

First and foremost, let's talk about the naming scheme since this was arguably the most controversial aspect of the Lynnfield series and it gets much worse with Clarkdale since dual-core/four-thread models have now been added to mix.

Intel have chosen their Core i3/5/7 naming scheme to help highlight the number of threads and specific technologies that each processors series supports. Simply put, Core i7 models are eight-thread processors which feature both Hyper-Threading (HT) and Turbo Boost technology. The Core i5 models are four-thread processors with Turbo Boost. The Core i5 series will now be particularly confusing to consumers though, since it is comprised of the 4-core/4-thread i5-700 series and the brand new 2-core/4-thread i5-600 series. Then we have the Core i3-500 series models, which are 2-core/4-thread processors but without Turbo Boost. Lastly, we have Pentium G6000 series, which will be dual-core processors without Turbo Boost or Hyper-Threading.

Within this mishmash of models there are now different core counts, different thread counts, different clock speeds, different Turbo Boost capabilities, different memory interfaces, different manufacturing processes, different IGPs (or none at all), etc. Goodluck Mr. and Mrs. Consumer, you are going to need it. Thankfully, Clarkdale does share Lynnfield's LGA1156 socket, so that is one area of familiarity.

Still confused? Well the tables below should help provide greater insight about the various Clarkdale variants.


At the moment, the only G6000 series that we are aware of is the G6950, although even lower-end models are almost a certainty. The G6950 is really quite different from the other Clarkdale variants since it is the only that does not feature Hyper-Threading (HT), and thus can only process two threads at a time. Unlike all the other Clarkdale variants, this model is also the only one with a cut-down L3 cache. Furthermore, it also features a slightly slower DDR3-1066 dual-memory memory interface and IGP core clock speeds. On the plus side, it should feature a sub-$100 price tag, which would make it a terrific replacement for the $110-120 Core 2 Duo E7400 2.8Ghz dual-core processor, especially when you consider the integrated graphics processor (IGP).

The i5-500 models are a healthy step-up from the aforementioned G6950. For starters, although they lack Turbo Boost, they do support Hyper-Threading, making them the very first dual-core/four-thread processors on the market. They also come with a full 4MB of L3 cache and dual-channel DDR3-1333 memory interface like the higher-end i5-600 series. Perhaps most importantly though, they have an IGP that is clocked at 733Mhz, which is a full 37% higher than the G6000 series. At $113 and $133 respectively, the i3-530 and i3-540 are priced quite aggressively and will obviously prove to be the dominant sellers in the Clarkdale family. It's clear that Intel is aiming these two models at AMD's very popular budget-oriented Athlon II X4 series. However, can a dual-core/four-thread design really compete with a proper four-core processor? Keep reading to find out.

As you can see, the four initial Core i5-600 series launch models are nearly identical. They all feature Hyper-Threading, Turbo Boost, 4MB of L3 cache, and a dual-channel DDR3-1333 memory interface. However, the i5-661 does distinguish itself from its twin i5-660, and all other Clarkdales, with a higher clocked IGP and proportionally higher TDP. Speaking of thermal design power (TDP), the 73W figure is not too shabby when you consider that this chip consists of both a 32nm CPU die and 45nm GPU die in one package. For comparisons sake, the quad-core Lynnfield and Bloomfield models come in at 95W and 130W respectively.

While the purpose and price points of the Pentium G6950 and Core i3-500 series are easy to understand and explain, things get a little more complicated with the i5-600 series. Not only do these new i5 processors infringe upon a model designation that was previously reserved for a quad-core model -the i5-750- but so do their prices. At $196 USD, the i5-660 and i5-661 models are priced exactly the same as the quad-core Core i5-750. Are the higher clock speeds and integrated graphics processors enough to warrant these relatively high price points? The benchmarks will shed light on that question.

The i5-670's price tag defies logic, but Intel always prices the highest-end model in each family above what most would consider reasonable. The i5-650 could potentially be a sweet spot for your average joe consumer, but that $43/30% price premium over the i3-540 is daunting for a mere 4% higher clock speed (up to 13% with Turbo Boost).

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