Video Cards And Power Supply
Video Cards: 2 x Radeon HD 5850 in CrossFire
The Radeon HD 5850 outperforms the GeForce GTX 285 at a lower cost, and we were looking forward to putting two of these cards in a CrossFire configuration to give our $1,300 system some hard-hitting graphics prowess.
Radeon HD 5850 cards were somewhat hard to come by in the weeks following their introduction, but it finally looks like there is a steady enough supply now. Unfortunately, organizing a System Builder Marathon (SBM) takes weeks to prepare and Radeon HD 5850s were still scarce when we ordered the parts.
While we wanted the cards that offered the best price/performance ratio--some Radeon HD 5850s can be bought for as low as $310--these low-priced specimens were not available when we ordered, so we were forced to take what we could get. We got our hands on two XFX HD-585A-ZNBC Radeon HD 5850 Black Edition cards (thanks, XFX!), which are factory overclocked models that cost about $50 more than a garden-variety Radeon HD 5850. The good news for whoever win's this month's $1,300 system is that you'll get a couple of super-charged graphics cards.
With Radeon HD 5850s now available for purchase at $310, here's what we've done: we've budgeted for the cheaper version of Radeon HD 5850s and underclocked our Radeon HD 5850 Black Edition cards to reference 725 MHz core/1,000 MHz memory speeds for our stock results. For our overclocked results, we pushed the cards to the maximum allowed in the BIOS, which happens to be 10 MHz core speed faster than the factory clock of the Radeon HD 5850 Black Edition at 765 MHz core/1,250 MHz memory. The overclocked results will give a clear indication of what the XFX card can do out of the box.
I will point out that it was very late in the game when we learned that the new 1.4 version of MSI's Afterburner overclocking utility has the ability to bypass the graphics card's imposed overclocking limits simply by selecting "Enable Unofficial Overclocking value to 1" option in the program's MSIAfterburner.cfg file. Overclocking results can likely be pushed much higher with voltage increases, so this is something to keep in mind for you overclockers out there. These cards will have a lot more potential for higher clocks than we achieved here if voltages are pushed and the BIOS limit is breached.
Power Supply: Corsair CMPSU-750TX
On sale for $110 with an additional $20 rebate, the Corsair CMPSU-750TX is a no-brainer for high performance and value. A single mammoth 60 amp rail will supply all the graphics power we'll ever need without complaint, and the 80 PLUS efficiency rating is very much appreciated.