Temperatures, Overclocking
With its low power consumption at idle and high-but-not-excessive consumption under load, we were relatively sure that with the GT200 Nvidia would maintain the reputation they’ve had since the GeForce 7800 GTX as a maker of relatively quiet high-end cards. We were wrong.
During Windows startup, the GT200 fan was quiet (running at 516 rpm, or 30% of its maximum rate). Then, once a game was started, it suddenly turned into a washing machine, reaching a noise level that was frankly unbearable – especially the GTX 280. The GTX 260 did slightly better, but also became noisy at 1250 rpm (the noise of the air flow, not of the fan itself). We should tell you, however, that our at-idle readings are taken after all our benchmarks have been run, after just a few minutes at idle. The problem is that the GTX 280 never really goes back to its minimum level, and the GTX 260’s fan, while it does better, still runs at 700 rpm – though that’s relatively quiet.
These results at idle are hard to understand given the GT200’s low at-rest power consumption, and must be the fault either of a problem with the BIOS (though it showed up on two different cards) or the drivers, which leaves hope for some progress. If not, it’ll still possible to slow the fan manually using special software, provided you keep an eye on temperatures (see the next page). Still, the fans are a big disappointment with these cards, especially when you consider that they blow part of the hot air back into the case and so contribute to heating it, which in turn causes the GPU fan to crank up, not to mention the other components.
Finally, we noted that, as in the case of power consumption, the results for the 3870 X2 under load were abnormally good, for the same reason: Test Drive Unlimited is one of the rare games with which only one of the card’s GPUs is really used, which limits heating.
Overclocking
In overclocking tests, we were able to push the GeForce GTX 260 from 576/1242/999 MHz (GPU/ALU/memory) to 648/1397/1184 MHz, or 12% and 18% respectively. That’s good, and let us squeeze out a gain of 16%, or 8.4 frames per second, at 2560*1600 with Test Drive Unlimited – only 6% slower than the GTX 280!
Except that obviously we overclocked it too – from 602/1296/1107 MHz to 655/1410/1290 with very good stability, for gains of 9% and 16%. Test Drive Unlimited again benefited from the boost with a 13% increase in frame rate – which is quite good even next to the 16% we got with the 9800 GTX. Overall, those results are very coherent, especially for overclocking, which is not an exact science.
