Spécifications
Thanks to its two GPUs at frequencies of 825 MHz, the Radeon HD 3870 X2 is the first graphic card to surpass a theoretical calculation power of 1 Gflops. On the other hand, compared to the Radeon HD 3870 its memory is set at a lower speed of 900 MHz instead of 1125 MHz. The fact that there is now two of everything allows doubling the memory bandwidth with the transition from 1 to 2 GPUs and gives the card this very high number. It’s the same for the GeForce 9800 GX2. Note that once again these graphic systems are the equivalent of one 512 MB card and not a 1 GB!
Power consumption and noise
We evaluated the power consumption of the different cards. Measurements were taken at the wall socket. This is therefore the total power consumption of the power supply, in this case a Cooler Master Real Power M1000 (1000 watts).
Use of the 55 nanometer process and PowerPlay in order to reduce consumption means the Radeon HD 3870 as well as the X2 are very economical in stand-by. The result, is that a GeForce 9800 GX2 consumes 50 watts more than a Radeon HD 3870 X2
In load, PowerPlay no longer gives the Radeon this advantage but the GeForce 9800 GX2 despite everything still consumes more. This is only logical given its higher calculation power.
Note that the GeForce 9800 GX2 is
Hybrid Power compatible and can therefore be entirely turned off when used in a system compatible with this technology (such as the future nForce 780a for AMD processors). We will have to wait for this summer until a similar alternative arrives for the Core 2.
In terms of noise, in load the GeForce 9800 GX2 is not in the silent category. While its cooling system runs at a relatively constant speed and unlike the annoying variations of the Radeon HD 3870 X2, it is equally as loud once the card is in action in heavy graphic scenes.
Drivers
Implementation on the driver level is identical to what was done for the GeForce 7950 GX2. The control panel reacts the same as with an SLI system except the word ‘’SLI’’ is replaced by ‘’multi-GPU’’ in order to keep the brand name for in-house chipsets. By default the multi-GPU mode is activated with the latest driver version.
You will have to deactivate it to use multiple screens because contrary to AMD, Nvidia still has not implemented this type of support with multi-GPUs. It’s a limitation which is starting to weigh heavily and is time to remedy.
The test
In this test, we used ten games, four of which support DirectX 10. Tests were carried out only in 1920x1200 as a lower resolution isn’t generally suited for such a high end product. Anisotropic filtering and HDR were activated in all cases when available in the game. Finally, transparency/adaptive antialiasing were activated in multisampling mode.
Of course, all updates to Windows Vista relative to performance were installed.
Configuration
Intel Core 2 Extreme QX9770
Asus P5E3
2 GB DDR3 1066
Windows Vista
Forceware 174.53
Catalyst 8.3
