Assembly And Overclocking
All of the components we picked fit nicely into Raidmax’s Atlas case, and we don't have any assembly problems to report.
The only stumbling block was a lack of four-pin power connectors needed to connect the included case fans. Corsair's CX600 PSU only comes with a quartet of those Molex plugs, and we used all of those up on dual four-pin-to-PCIe power adapters for the GeForce GTX 460 cards in SLI.
In order to solve that problem, we used a single Molex-to-PCIe adapter we had in the lab, freeing up a fourth four-pin connector for fan duty. Although we didn't run into any stability issues using the CX600, we probably won’t be picking it for a dual-graphics-equipped machine in the future.
The small EVGA P67 Micro motherboard accommodates two graphics cards without difficulty, but doesn’t leave the top card a lot of room for airflow. Because the graphics cards are relatively close to the processor, we'll orient the CPU cooler to pull air from the right side of the chassis.
We’ve overclocked a handful of Core i5-2500Ks now, and the majority of them top out with a 45x multiplier at 1.4 V using entry-level aftermarket air cooling. The specimen in this build is no different. When we bumped its multiplier to 46x, one of the execution cores suffered an error in our Prime95 stress test.
The Cooler Master Hyper TX3 does a good job considering its sub-$20 price tag, and our final CPU overclock is 4490 MHz with a 45x multiplier. Memory performance is also improved over default settings, since we're able to invoke the XMP memory profile option in EVGA's BIOS, cranking the frequency up and timings down, from 9-9-9-24 1T at 666 MHz to 7-8-7-24 1T at 800 MHz.
As far as graphics cards are concerned, we usually find that overclocking is hamstrung when we start messing with dual-card solutions. This time around, though, our results are encouraging: with the GPU voltage raised from 0.937 to 1.0 V, we manage to push the core clock from 720 to 850 MHz. The memory also jumps from 3600 MT/s to 3700 MT/s. Moreover, we're cranking the fans up to 100% for stress testing purposes (Ed.: Hey now, I'd consider that cheating if I were Thomas or Paul).