Noise and Power Consumption
The reference cooling system developed by Nvidia for the GeForce 8800 series is highly effective and rather quiet. We had already learned its noise characteristics before, yet we wanted to see how the modified cooler of the e-GeForce 8800 GTS 320MB KO ACS3 compared with the reference GeForce 8800 cooler.
Our measurements showed that there were no differences: the six graphics cards were all working quietly despite the difference in their clock rates. If you’ve got additional system fans in your gaming system and the system case is ventilated properly, there is very little chance that you ever hear the GeForce 8800 raise its voice even during a long play. Moreover, the GeForce 8800 GTS 320MB does not generate as much heat as the GeForce 8800 GTX does. With their noise characteristics these graphics cards successfully rival the Radeon X1950 XTX whose cooling system is deservedly regarded as one of the best cooling solutions.
We had already measured power consumption of the GeForce 8800 GTS 320MB, but we wanted to check out the pre-overclocked version of the card, too. So, we took the EVGA card as having the highest GPU and memory frequencies among all the six. We performed our power consumption tests on a special testbed equipped with connectors for measuring instruments.
- Intel Pentium 4 560 CPU (3.60GHz, 1MB L2);
- Intel Desktop Board D925XCV mainboard (i925X);
- PC-4300 DDR2 SDRAM (2 x 512MB);
- Samsung SpinPoint SP1213C HDD (120GB, Serial ATA-150, 8MB buffer);
- Microsoft Windows XP Pro SP2, DirectX 9.0c.
The measurements were performed with a Velleman DVM850BL multimeter (0.5% accuracy).
We loaded the GPU by launching the first SM3.0/HDR graphics test from 3DMark06 and running it in a loop at 1600x1200 resolution with 4x full-screen antialiasing and 16x anisotropic filtering. The Peak 2D load was created by means of the 2D Transparent Windows test from Futuremark’s PCMark05 benchmarking suite. Here are the results:
Obviously, it is the 6-pin PCI Express connector that bears the biggest load, just as is the case with the GeForce 8800 GTS 640MB. However, the simple formula I=P/U gives out a current of about 5.6A for this connector, so the GeForce 8800 GTS 320MB can be easily powered up by a quality ATX 2.0 power supply with a wattage of 350W and higher provided that the remaining capacity of the PSU is enough to power the rest of the gaming system components. On our part, we can say that not only all versions of GeForce 8800 GTS 320MB, but also the much more voracious GeForce 8800 GTX worked without problems on our Cooler Master RS-450-ACLY that provides a combined current of 22A on the +12V rail (this is lower than 29A the standard 400W ATX 2.0 power supply must provide and corresponds to the standard 300W unit).
The EVGA card demands more power, yet its power draw does not reach 120W, either. The load on the external power line is increased from 5.6A to 6.2A, so the PSU requirements remain the same. The only recommendation, which is true not only for GeForce 8800 GTS 320MB but for other graphics cards as well, is that you should avoid cheap models from obscure manufacturers that may prove to have worse effective parameters than declared. Their output voltages may not be stable and their output voltage ripple may be too high for normal functioning of your system.
As for those versions of GeForce 8800 GTS 320MB that are not overclocked as heavily as the EVGA card, they should have a peak power consumption of 105-112W and there are no special PSU recommendations for them. Everything we’ve written above is true for such cards, too.