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Gainward GTX 480 runs at 700/1401/924MHz for the GPU/Shaders/Memory, meaning the card kept reference clocks. Naturally, the GF100 graphics processor packs more punch than that but the GPU’s thermals made things extremely difficult. In fact, Nvidia strapped the GTX 480 with a large dual slot cooler with 5 heatpipes and the card still easily hits 90°C in 3D. Note however that even if you do notice higher temperatures, you need not worry as the default cooler will definitely keep things in check. When temperatures exceed 91°C, fan spins faster and the temperatures quickly revert to 91°C.
Unfortunately, while the cooler is capable of keeping the temperatures in check, it does get very loud. On the other hand, the card is pretty quiet in idle mode but you’ll definitely hear it in graphics-hungry apps or games.
Naturally, any overclocking requires sacrificing silence. For comparison purposes, with the fan running at Auto RPM we managed to overclock Gainward’s GTX 480 card to 760MHz. After manually setting the fan at maximum RPM we managed to push the card to 810MHz, without meddling with voltages. Note that we experienced most overclocking problems with the memory which wouldn’t run higher than 985MHz (3940MHz effectively).
We performed our overclocking via the ExpertTool, which supports Fermi cards in its latest v7.8 version. The ExpertTool we found on the CD is up to date and we’ve seen that the same version can be downloaded for Gainward’s web portal. ExpertTool runs with all Gainward’s cards starting from Nvidia’s 8th generation, with driver version 180 and newer. It’s well worth noting that ExpertTool v7.8 allows for independent overclocking of the core and shaders, which we couldn’t do when we tested the reference card more than a month ago – GPU clocks were linked to shader clocks in ratio 1:2.
We monitored fan speed via GPUZ tool, and it shows that maximum RPM is 4800. NVIDIA uses a Delta fan, which is rated at 1.8 A.
Besides cranking up noise levels, overclocking introduces higher consumption as well. We don’t have the appropriate equipment to measure exact consumption of the graphics card so we measured our entire rig’s consumption (without the monitor). Overclocking the card increased the consumption by about 30W, which means the entire card consumes about 280W. Note that this is seriously close to 300W, which is the maximum power the card can draw via one 8-pin and one 6-pin power connector.
We measured maximum temperatures using FurMark, which really knows how to stress a GPU and push temperatures higher than games can. We noticed that the fan starts spinning much faster when temperatures exceed 91°C, which is somewhat of a thermal safety net. Maximum temperature was at 96°C with the room temperature around 23.6°C.
Unfortunately, the fan couldn’t lower temperatures to 91°C during our overclocking. After ten minutes of Furmark, temperatures rose to 96°C and we even measured 97°C after half an hour. We didn’t go further for the risk of damaging our card, but this proves that GTX 480 overclocking is indeed possible. Still, we’d advise using water cooling or some more efficient cooling solution if overclocking is what you’re after.