Having already tested the AMD Radeon HD 7990 6GB with its out of the box performance, the next step after that is to check out the overclocking side of things. Performance of the new AMD model is exceptionally strong - with the $999 price tag and the fact it's a dual GPU card, though, we wouldn't expect anything less from it.
There's really not a whole lot that needs to be said from an introduction stand point. We really just finished looking at the HD 7990 6GB and we're going straight into overclocking. What we'll quickly do is talk about the overclocking below before looking at our testbed, the cards that we'll be using in our graphs today before we get into the performance.
Normally we fire up MSI Afterburner to do all our overclocking. Inside we found that we didn't have any voltage adjustment. That was not a huge surprise, though, considering the model has just launched. If we see it in the next few weeks, only time will tell. With that said we went straight into the core clocks to see just what we could get out of the new video card. We pushed the cores up to 1150MHz, but as soon as we started to run 3DMark 11, our system froze.
We rebooted and went back to MSI Afterburner. We then upped the core clocks to 1100MHz. We completed the run with no issue, but the final score was near identical to the default run - it was actually slightly less. Doing a little bit of research I discovered that we weren't the only people to run into this problem.
Moving away from MSI Afterburner we decided to jump into the Catalyst Control Center instead and see if we had any more luck. While we don't have the same kind of range when it comes to clocks, the 1100MHz limitation on the core should be fine, especially when we don't have the ability to adjust the voltage of the core at this stage.
In the end we had the reference video card running at 1100MHz on the core, up from 1000MHz. The 6GB of GDDR5 was increased from 6000MHz QDR to 6300MHz QDR.
The results were kind of interesting and we'll discuss it in more detail as we go through our graphs. As we mentioned before, though, let's quickly take a moment to look at our testbed and the cards that will be alongside the overclocked HD 7990 6GB here today.