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System Builder Marathon, August 2012: $2000 Performance PC

Pushing GeForce GTX 670 To Its Limit

Editor-in Chief Chris Angelini and I don’t exactly agree on the usefulness of power management schemes enabled on today's graphics cards. Chris’ take is that boosting to higher frequencies during periods of sub-maximum thermal load helps make games run faster, which may be true. My take is that average frame rates probably increase, but higher clocks don't necessarily cut into the maximum frame rendering time that can ruin a gaming experience (Ed.: Actually, I'd agree). My argument states that, since the toughest-to-render frames can push 100% GPU power, those same frames force the GPU down from its boosted clock rate to its base frequency.

Increasing the amount of time spent at higher clock rates (GPU Boost) has the same effect as decreasing the amount of time spent throttled-down, reducing the likelihood that the GPU will slow when you need it to run as fast as possible. The only way to do that is to increase its power threshold, which we did by maximizing the power target in EVGA Precision X.

The effect of increasing the power target could be easily observed from the utility itself while running a game in windowed mode. The graphics card’s power limit still appeared to be an issue, though, so I dropped the base voltage from 0.98 to 0.85 V. We seemed to get another gain in the amount of time it spent running at its boosted speed.

Noisy fans might be OK during a game, but nobody wants to listen to them all day. EVGA Precision X ships with a multi-point fan map, which I altered from a curve to a lower-temperature slope by deleting and moving some of its points. You can fine-tune even more if you want, but that's not necessary for our performance analysis.

Now, maybe you're wondering why I didn’t mention the frequencies I achieved, evident in the top image on this page. Yes, I pushed the GPU Boost frequency to 1301 MHz and the card's memory to GDDR5-7048 data rates. Rumors that GeForce GTX 670 overclocks better than the GTX 680 might be true, but frequency gains compared to our previous GTX 680 effort are fairly minor. Higher base voltage levels appear to cut into the amount of time spent at boosted clock rates without increasing the GPU’s stable frequency, and offset voltage level wasn’t adjustable separately.