The AMD R9 290X is an extremely potent graphics card, but it needs more cooling performance than the reference cooler can provide. The GPU base clock is 1000MHz, but only after a few minutes under load the clock drops to around 850MHz. The card does not have a minimum 3D clock, so it is possible to see even lower clocks if you heat up the card.
PowerTune 2 is constantly stepping in to rigorously control the temperature. As soon as the card hits 95 degrees Celsius, the clocks go down and don’t recover until the temperature goes down. In Quiet mode the fan maxes out at 2200RPM, while in Uber mode it can exceed 310RPM. Obviously, a lower fan speed results in less noise and less performance and the opposite is true of Uber mode.
The performance of the R9 290X in Quiet mode can match the GTX 780, but in Uber mode the card can easily go toe to toe with the new GTX 780 Ti. It is abundantly clear that the cooler is the biggest bottleneck for the R9 290X.
Once the card heats up, the average GPU clock in Quiet mode drops to 850MHz or lower, but the card is so powerful that in most games this won’t result in a noticeable performance penalty. However, if more intensive tasks like 4K or data processing are required, Uber BIOS can be used to unlock additional potential of the card.
To activate Uber BIOS, all you need to do is flip the dual BIOS switch right. With Uber BIOS, PowerTune 2 is less aggressive and it will allow the card to hit 1000MHz and keep the clocks from dropping below 900MHz. To squeeze out more performance without a reboot and BIOS switch, you can also manually adjust the fan speed to 55 percent.
We tested most games with both BIOS settings and the results prove higher fan speeds have a huge impact on performance. This is especially true of more demanding benchmarks. In Futuremark the difference is negligible as the test is too short and doesn’t heat up the GPU too much.
We are still somewhat concerned by certain R9 290X performance issues. Several reviewers have noticed that retail cards are somewhat slower than press samples sent out ahead of launch. AMD said it has noticed fan speed oscillations in some cards and a driver revision was released to solve the problem. With the new Beta9.2 driver the Quiet BIOS fan speed target is placed at 2200RPM. In previous versions it was accompanied with a 40 percent barrier. AMD quietly used its chance to give the fan a slight bump and increase performance. This also results in more noise, but the performance gain is noticeable and the temperatures are lower. As far as our sample is concerned, it worked just fine even before the update, but after the update we noticed that Quiet mode fan speeds went up, while clock oscillations are smaller.