Intel Core i7 2600K and Core i5 2500K Reviewccokeman - January 2, 2011
Price: Core i5 2500K $216, Core i7 2600K $317
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It's that time of year when the new technology start running out the doors and it becomes really interesting to see what has been brewing for the last year. For Intel, it has been cooking up a new processor line for the mainstream market that has been codenamed Sandybridge. If you have looked hard enough and carefully digested and read through the quick looks and pre-release articles, you could see where the performance lies and what this processor can do. One of the biggest things that has been rattled around in the forums has been the fact that overclocking on an Intel processor is officially dead. This could not be further from the truth. It's just that you have a different way of overclocking, much the same way we had to learn what the quirks of the Nehalem micro architecture were to get the most out of it. Sure bclock limitations are there, as most of you have read, but Intel has not locked out the enthusiast with the inclusion of a pair of K-Spec processors that are tailored to the mainstream enthusiast in the second generation Core i5 2500K and Core i7 2600K. Based on some of the overclocking I have seen, they just might move further up on the price/performance ladder and are easily a replacement for the current socket 1156 lineup where overclocking is concerned. Priced at $216 for the 2500K and $317 for the 2600K, they are less than $20 more than the current K-Spec Core i7 875 and Core i5 750. For that price, you get a processor with Intel's HD 3000 series integrated graphics built into the core for use in supporting H67 chipset motherboards.
These chips sport all new features, such as Turbo Boost Technology 2.0, Unlocked CPU, GPU and Memory multipliers, dual-channel memory support, XMP support, and a host of graphics enhancements with Intel Quick Sync Video technology, Intel In Tru 3D for full stereoscopic 1080p playback, and Intel Advanced Vector Extensions (Intel AVX) to help performance in video editing applications. It looks like Intel has taken Clarkdale several steps further up the performance ladder. Let's see how these new additions to the Intel family compare to the current crop of Intel and AMD processors. It looks like the media PC has come full circle and eliminated the past bottlenecks to performance.
The first CPU I have here is the the second generation Core i7 2600K. These CPUs are designed to work with Intel's 6 Series chipset socket 1155 motherboards. The K-Specification at the end of the model number signifies that this CPU has its Turbo Multipliers unlocked for overclocking headroom and is an overclocking-enabled processor. This CPU has a base clock speed of 3.4GHz that is reached using a bclock of 100 with a multiplier of 34 and a Turbo Boost multiplier of 38 for additional speed in lightly loaded situations. The second generation Core processors are an architectural change and are built using Intel's 32nm process. The 2600K has four cores and supports Intel Hyper-Threading for a total of eight threads that can be run simultaneously. The 2600K is equipped with 8MB of shared cache that is dynamically allocated to each core to reduce latency and improve performance. The big change for this lineup is the inclusion of the Intel HD 3000 graphics processor that is built into the core. As an overclocking-enabled processor, you can increase the Turbo Boost multiplier for the core, the memory multiplier, and the graphics core multiplier to increase performance across the board. The 2600K supports DDR3 memory at 1333MHz in a dual-channel configuration, much like the previous generation Core i7 875. The TDP for this processor and the 2500K comes in at 95W. Pricing should be $317, or a $23 premium over a non K-Spec CPU.
The 2500K is, for all respects, a 2600K minus Hyper-Threading, a small drop in clock speed to 3.3GHz, and a reduction of the shared Intel Smart Cache to 6MB. This CPU is also overclocking-enabled with an unlocked CPU, GPU and memory multipliers. One thing the unlocked processors have that the locked 2600 and 2500 does not is the HD 3000 graphics, in lieu of the HD 2000, so for the price premium of $11, you get the increased capabilities on the graphics side as well.
The retail packaging has shrunk down alongside the die shrink to 32nm. The front of the packaging illustrates that these CPUs are Unlocked and Unleashed, showing the enthusiast nature of the K-Spec processors. The smaller packaging also gives you an indication of the size of the included heat sink. The packaging for the Core i5 2500K and the Core i7 2600K is shown below.
Since Intel designed these chips to be overclocked, Intel supplied us with its DHX-B tower-style heat sink to use when overclocking these processors. This tower-style heat sink uses three heat pipes and is almost a mirror image of the design delivered with the 980X. Along with this heat sink was the DHA-A stock thermal solution. By comparison, there is a huge difference in thermal performance between the two designs. The DHX-B is the one used in our testing.
Architecturally, the second generation Core processors are part of Intel's Tick-Tock strategy where a Tick is a process change and a Tock is a new micro architecture design. The Sandybridge lineup is a Tock, with a completely new architecture that includes a graphics engine as part of the core, not just an add-on under the heat spreader. The Sandybridge processors are built using Intel's 32nm High-k second generation manufacturing process for the whole core, instead of the 32nm core and 45nm GPU core on the Clarkdale dual-core processors released earlier this year. Below is the die shot showing how each part of the chips is allocated, along with an overview of the core components.
To support the second generation K-Spec processor lineup are the H67 and P67 chipsets. The H67 is designed more for the media specific PC that is used to view and manipulate digital content, whereas the P67 is geared more toward the power user with the absence of any integrated video support. This means you will need to use a discrete video card when purchasing a motherboard equipped with the P67 chipset. The H67 chipset supports dual-display functionality with DVI, HDMI and DisplayPort connectivity.
Now that we have seen what the processors have to offer, I can take a look at Intel boards that support the Core i5 2500K and Core i7 2600K and see just what kind of performance they deliver.