Assembly And Overclocking
The Xclio Nighthawk case is surprisingly pleasant to work in. There are a lot of cable management features you don't even see in more expensive models, plus a number of easy-access panels that open up to make optical and hard disk drive installation simpler. This enclosure is fairly roomy, and has no problem accommodating two Radeon HD 6850 cards. It's attractive enough with the fan LEDs turned on, but the control panel on top lets you turn them off if bling is not your thing. Either way, the Nighthawk has a classy look that'd make us think it's more expensive than it really is.
The build went smoothly, and there were only two issues to note. First, CrossFire did not work until I updated the motherboard's firmware to the newest option available, version 1B. The second issue was a surprise: the Gigabyte Radeon HD 6850 cards don’t come bundled with a CrossFire connector! Luckily, we had a spare lying around the lab, but folks who don’t have that luxury will be disappointed. A CrossFire bridge should automatically be included with cards this powerful, and we encourage all graphics card vendors to keep that in mind.
The MSI P67A-G43 has a great BIOS interface to work in; it's straightforward and easy to navigate. We were surprised to see some simple games bundled in the firmware itself, and to be honest we’re not sure if this feature would ever be used. But if MSI wants to add it for free, who are we to suggest otherwise?
We’ll employ the same overclocking approach used in our previous System Builder Marathon configuration: feed the Core i5-2500K CPU 1.4 V, turn Turbo Boost off, and find the highest multiplier that it’ll take without crashing or throwing up unacceptable temperatures.
As in our last SBM, this CPU won’t run stably with a 46x multiplier, but it's rock-solid at 45x. This results in a 4.5 GHz clock, and in a Prime95 stress test, it caps out at about 90 degrees Celsius, or about 10 degrees short of its thermal limit. That's more than 20 degrees warmer than the ceiling we saw last quarter, so it's pretty easy to conclude that Cooler Master's Hyper 212 is a much more capable heat sink. Having said that, the Xigmatek Loki also costs half of the price and still makes this overclock possible. Most of the time, actual operating temperatures should remain far below what a synthetic stress test like Prime95 yields, too.
We’re not keen on pushing things as hard when graphics are concerned, as dual-card configurations tend to sacrifice stability when overclocked. As a result, we’ll limit ourselves to what the Catalyst Control Center’s Overdrive tool allows. We are able to push the cards to 875/1100 MHz GPU/memory from the stock 820/1050 MHz specification.