To overclock the AMD Radeon HD 6800 graphics card series we could use the ATI
Overdrive utility that is part of the CATALYST Control Center, but if we do we are limited to 1000MHz on the core clock and 1250MHz on the memory clock. We wanted something that had the ability to go even further and have the ability to increase the cards’ voltage.
One of the only utilities for this happens to be Sapphire’s new overclocking utility called TRiXX. This utility isn’t public yet, but Sapphire sent us over version 0.4.17 to try out. As you can see from the screen shot above you can adjust the core and memory clocks along with the GPU voltage. You can also control the fan speeds and get basic information from your AMD Radeon HD 6800 series video card with this overclocking application.
In the image above you can see the max overclock settings allowed by TRiXX. As you can see the core is no longer limited to 1000MHz and can go all the way up to 1300MHz. The memory clock frequency limit has been increased from 1250MHz to 1500MHz. The GPU voltage on all of our Radeon HD 6870 cards was observed at 1174 according to TRiXX. For overclocking our three AIB Radeon HD 6870 video cards we cranked up the voltage to 1300 and found the limits of each card.
The first video card we overclocked was the Diamond Multimedia Radeon HD 6870 XOC. This card was already factory overclocked, so we weren’t sure what to expect. We were shocked to see that we got another 105MHz out of the GPU Core Clock and exactly 100MHz extra from the memory. Reaching a core clock of 1045MHz was awesome to see, but we were disappointed with the memory performance. The memory on this card was the limiting factor in our overclock as anything over 1200MHz and we’d get freezes and stutters in games.
The Sapphire Radeon HD 6870 video card did awesome on overclocking and was able to reach a GPU core clock speed of 1045MHz and a memory clock speed of 1235MHz. This is a 155MHz increase on the GPU core clock and 185MHz on the GDDR5 memory!
The XFX Radeon HD 6870 video card overclocked up to 1025MHz on the core and 1240MHz on the memory clock. This is a 125MHz increase on the GPU core clock and 190MHz on the GDDR5 memory. We wished the core clock speed had a little more in it, but this is still a nice overclock. In fact, all three of these overclocks are very nice. The best overall overclock was on the Sapphire Radeon HD 6870, though, as it had a core clock of 1055MHz and 1235MHz on the memory. Let’s take a closer look at what that cards’ overclock does for performance.
The Sapphire Radeon HD 6870 Video Card Stock 900MHz/1050MHz:
The Sapphire Radeon HD 6870 Video Card Overclocked 1055MHz/1235MHz:
As you can see this massive overclock took our card from a 3DMark score of ~X7700 all the way up to ~X9000! This is a solid 17% improvement in performance and a rock solid overclock.
Real gaming performance also improved as you can see from AvP above. We went from 26.1 to 30.5 frames per second on the Sapphire Radeon HD 6870 by overclocking it! This is a 17% improvement as well and puts the Radeon HD 6870 next to the Radeon HD 5870 in terms of performance! Overclocking is always worth it if you want an extra performance boost for free!