The new CPUs are built on a brand new microarchiture, and boast superior integrated graphics performance and improved energy efficiency. For our tests, we looked at a pair of processors: the 3.3GHz Core i5-2500K ($216), and the 3.4GHz Core i7-2600K ($317). The second-generation Core CPUs follow a slightly different nomenclature to the Core CPUs you're likely already familiar with. The Core i3, i5, and i7 branded chips remain. The number that follows the i3, i5 or i7 -- a "2" -- indicates that the chip is a second-generation CPU, and part of the Sandy Bridge family. The three numbers following the "2" indicate the specific processor model. The two chips we reviewed are followed by a "K," indicated they are unlocked, and primed for overclocking.
For a detailed run-down of all that Sandy Bridge has to offer, be sure to check out our overview of the new features baked into the second-generation of Intel's Core processors.
Testing Sandy Bridge
For the Core i5-2500K, Intel provided the DH67BL "Bearup Lake" motherboard, which is equipped with Intel's second-generation integrated graphics on the H67 chipset. For the Core i7-2600K, we're using the DP67BG "Burrage" motherboard, sporting the performance oriented P67 chipset.
New CPUs, new chipsets, and -- much to the chagrin of serial upgraders -- new sockets. The second-generation Intel CPUs are using the LGA-1155 socket, so you'll need to pick up an entirely new motherboard if you're planning on picking up a new CPU.
Both testbeds were outfitted identically: 4GB of DDR3 RAM, a 1 TB hard drive, an AMD Radeon HD 5870 graphics card, and an optical drive for loading applications. Occasionally, the graphics card on the i5-2500K testbed was removed for comparison testing of the H67 chipset's integrated graphics. The processors were left at their stock clock speeds. All told, our testbeds would cost under $900 to assemble. A pair of machines equipped with the Sandy Bridge CPU were provided by MicroExpress and Origin, and they sported generous overclocks. Lets check out the results!
Performance: WorldBench 6
First up is PCWorld's WorldBench 6 benchmark suite. For the uninitiated: WorldBench consists of a series of tests using real world applications to gauge a PC's performance. A series of applications run, simulating a typical workload. A WorldBench score is then compiled based on how long it took the machine to complete tasks. The results on our reference boards are impressive: Our Core i7-2600k earned a WorldBench score of 156, while the Core i5-2500K earned a 150.
Let's put those numbers in perspective. Back in August we reviewed Maingear's F131, a $2000 Mainstream desktop equipped with a Core i5-655K processor, 4GB of RAM, and a 1TB hard drive. It earned a WorldBench score of 152, but only after Maingear overclocked the CPU all the way up to 4.5GHz.
MicroExpress sent over theMicroFlex 25B, an $850 desktop equipped with the Core i5-2500K, 4GB of RAM, and a 300GB hard drive. It was overclocked to 4.1GHz, and earned a staggering 188 on WorldBench -- a result typically reserved for the upper echelons of the Performance category, in machines that cost upwards of $2000.The top tier isn't exactly slouching, either.
Origin provided their latest Genesis, equipped with a Core i7-2600K overclocked to a blistering 5GHz. This $7000 juggernaut is packed to the gills with all of the latest and greatest hardware, and earned a 223 on WorldBench -- the highest score we've ever seen. Be sure to check back for full reviews on both machines.
Next: Game performance testing and media-encoding tests