The graphic card, power consumption, noiseFor the GeForce 7800 GTX test, NVIDIA sent us two 256 MB graphic cards. This gave us the possibility to provide results with and without SLI. The graphic card is rather long, slightly bigger than a 6800 Ultra (21.7cm) and equivalent to a 6800 Ultra 512 MB (23 cm). The PCB is in fact quite similar to the 6800 Ultra 512 MB and only one memory space out of two is occupied by the Samsung 1.6ns chip, proof that a 512 MB version is possible.
The cooling system is similar to the GeForce 6800 GT’s, with an identical fan and an improved heatsink, and is still single slot. In practice the 7800 GTX is notably less noisy than a GeForce 6800 Ultra and even a 6800GT in 2D (in this mode the GPU is clocked at 275 MHz) and in 3D. The noise level is very reasonable and won’t disturb silent computers enthusiasts.
In terms of functioning temperature, according to NVIDIA’s monitoring after 10 minutes of 3DMark05 Game Test 4, the 7800 GTX reached 75°C, instead of 69°C for the GeForce 6800 Ultra. This chip, therefore, reaches quite elevated temperatures and it is probably due to the less noisy fan. We are still however far from NVIDIA security level of 115 °C. The GPU Overclocking seems quite easy because we easily reached 490 MHz instead of the initial 430 MHz. It looks like NVIDIA leaves some margin of progression for an Ultra version...
Of course, we evaluated the various graphic cards´ power consumption. These measurments were taken directly from the electrical plug, which therefore corresponds to the computer´s total power consumption (with an Enermax 535W). The figures reported were obtained in Windows desktop and in load with 3DMark05 in GameTest4 and Prime95. Prime95 helps to obtain constant processor use regardless of the graphic solution´s performance.
In 2D, the GeForce 7800 GTX´s power consumption is lower than its is with the 6800, but still not at ATI’s level. In 3D, the X850 XT PE is the more power hungry, whereas the 7800 GTX´s power consumption is slightly higher than the 6800 Ultra. This difference, however, is quite moderate.
Speaking of power consumption, NVIDIA indicates that a configuration with a 6800 Ultra requires a 400 Watt power supply, instead of a 350 Watt with a GeForce 7800 GTX. The manufacturer also specifies that for both cards a 500 Watts power supply is required for SLI. We don’t understand here why NVIDIA recommends 50 Watts less with a single 7800 GTX graphic card configuration and 150 additional watts are required for another 7800 GTX. With one of the two graphic cards, we advise you to use a good 350 Watt power supply and a good 450 W for SLI.