Even overclocked, AMD keeps a lid on power consumption
Once upon a time, factory-overclocked graphics cards with custom coolers shipped a few months after the reference cards were out. So, you’d typically end up with a pricier, slightly faster graphics card to replace the one you might already own—not a particularly cost-effective scenario.
Today, we’re seeing some customized cards ship at nearly the same time as reference cards. So it is with the Asus EAH6850 DirectCU. Asus takes its DirectCU feature, which runs the heat pipes directly across the GPU chip, pushes the clock speeds up slightly, and ships the card for roughly the same price as a stock HD 6850. Asus also bundles its voltage-tweak utility, which lets you change the voltage and push clock rates even higher, if you like.
Asus pops on a custom cooler, overclocks the Radeon HD 6850, and keeps the price in check. What more could we ask for?
Asus’s DirectCU version of the HD 6850 defaults to a slightly higher clock speed than the reference card—790MHz versus 775MHz. The memory clocks remain the same, at 1GHz. In addition to the non-standard cooler, Asus changes up the output connectors, offering a pair of DVI ports (only one is dual-link), an HDMI port, and a full-size DisplayPort connector, instead of two Mini DisplayPort jacks, as in the reference card.
Such a small overclock—not even 2 percent—nets only slight frame-rate gains against a stock-clocked card. But what about that more important question—how does it fare against its Nvidia contemporaries?
As you can see in the benchmarks, it’s actually a pretty close race between the overclocked Gigabyte GTX 460 and the EAH6850 DirectCU. The Nvidia-based Gigabyte card wins a few, the EAH6850 wins a few. Full-throttle power consumption, though, belongs to the AMD GPU all the way. Of course, Nvidia’s GPUs offer stereoscopic 3D support through its 3DVision feature, while AMD is relying on third parties to deliver the technology. On the other hand, AMD’s Eyefinity feature lets you connect up to three 1920x1200 pixel displays to the EAH6850 with just a single card. The choice comes down to which feature set is more important, rather than performance differences.
Pricing is pretty equivalent, too. We found one store offering the EAH6850 for $185, but most places seem to offer it for $200—right in the same ballpark as the 1GB GeForce GTX 460. The EAH6850 has efficiency on its side, but the performance of both cards and pricing are about even. Given that Radeon HD 6870s cost only $30–$40 more, we recommend going with the higher-end card. But if your budget is tight, Asus’s take on the HD 6850 is rock-solid.
Asus EAH6850 DirectCU
Good performance; power efficient; three displays with one card.
Slightly pricier than stock cards; only a single DisplayPort connector.
Asus EAH680 DirectCU
XFX Radeon HD 6850
Asus GTX 460 768MB
Gigabyte 460 GTX 1GB
3DMark Vantage Perf
Unigine Heaven 2.1 (fps)
BattleForge DX11 (fps)
Far Cry 2 /Action (fps)
Far Cry 2 /Long (fps)
HAWX 2 DX11 (fps)
STALKER: CoP DX11 (fps)
Just Cause 2 (fps)
Aliens vs. Predator (fps)
Dirt 2 (fps)
Power @ idle (W)
Power @ full throttle (W)
Our test bed is a 3.33GHz Core i7-975 Extreme Edition in an Asus P6X58D Premium motherboard with 6GB of DDR3/1333 and an 850TX Corsair PSU. The OS is 64-bit Windows 7 Ultimate. All games are run at 1920x1200 with 4x AA.