Overclocking Using RivaTuner And Tray Tools
RivaTuner only supports ATI cards indirectly, but you can still adjust the frequencies and the fan speed. Depending on the card and driver version you use, you may run into some trouble, though, since adjusting the clock speeds may also change the 2D profile on ATI cards. Normally, a Radeon HD 4870 runs at 500/900 MHz (GPU/Memory) in 2D mode. If you overclock the GPU in 3D mode by increasing its clock speeds, the card may not be able to drop back down to its 2D clocks. If it gets stuck in (overclocked) 3D mode, you’ll be faced with higher power consumption (as much as 15 Watts) and a louder fan as well. You can also use RivaTuner to create your own software-based fan speed profile. In the case of our MSI R4870-MD1G, that wasn’t necessary, as its automatic fan speed regulation worked as advertised.
RivaTuner gives you a wider range of frequency options that can also be used to underclock your card, reducing its power consumption. While AMD sets the lower limit for the card’s clock speeds to 750/900 MHz (GPU/Memory), RivaTuner allows you to run your card as slow as 375/450 MHz, reducing power consumption by up to 18 Watts. The fan speed remained the same in 3D mode, but GPU temperature dropped by 5 degrees Celsius.
While we didn’t encounter any problems with our card, other combinations of cards and drivers may have trouble bumping the video memory back up to its original level when 3D load is applied. Looking at the default profiles, we realized that MSI’s ATI card always runs onboard memory at its full 3D speed, even in 2D mode, instead of slowing it down when the card is idle. Since this is a well-documented problem, your best approach is to try how your own hardware reacts to any changes you make.
|2D Mode||Clock Speeds (GPU/Memory)||Watts 2D||Temperature 2D||dB(A) 2D|
|Underclocked w/ Riva Tuner||375/450||160||41.0||36.0|
ATI Tray Tool is another interesting utility, and it was written specifically with ATI’s Radeon graphics cards in mind. Sadly, underclocking did not work. Although the appropriate frequencies showed up on the slider, any changes were ignored and the sliders reset to their original positions.
The ATI Tray Tools come into their own where overclocking is concerned, though. They even offer a built-in test feature that checks for artifacts resulting from exceedingly high clock speeds. You can also adjust the voltages from within the Tray Tools, which can help stabilize an overclock. However, you should only make any sort of change here if you are absolutely certain you know what you’re doing and realize you are risking damage to your card. Even without a voltage increase, it’s entirely possible a component may not be able to take the additional strain resulting from higher frequencies, and this risk is only exacerbated when more voltage is applied. So just be aware that you’ll almost certainly void your warranty as soon as you start using your card outside of its intended specifications.