A lot of you reading this will likely have skipped all of the benchmark pages (shame!) and come right to one of the pages that really matter in a retail card roundup. Overclocking the Radeon R9 280X is just like overclocking the Radeon HD 7970 cards and, as it turns out, our experiences matched that expectation.
For each overclocking testing we used the manufacturers own overclocking utility to give each card the best chance for success. For example, the ASUS software increases voltages automatically when increasing the clock speed. As always, your mileage will vary and your overclocking experiences will likely be different than mine. These results are included merely to give you an idea of what we saw.
ASUS DirectCU II Overclocking
The ASUS DirectCU II TOP R9 280X card has a great cooler, a great PCB design, and the available software for overclocking it is top notch as well. During my use it recognized the card as a Radeon HD 7970 (doh!). That simply means the software needed an update for the new R9 280X branding
I was able to overclock our ASUS DCII card from the 1070 MHz box clock up to 1175 MHz with a corresponding voltage of 1.269v. Memory speeds were bumped up to 1800 MHz without issue. Both of these clock settings remained stable throughout our tests and loops of Unigine Heaven (a great way to stress clocks and power).
MSI Twin Frozr Gamer Overclocking
MSI has probably the most popular software for overclocking GPUs with Afterburner. The good news is that they don't lock it down to their own cards. Users of ASUS, Sapphire, HIS and even others (including NVIDIA cards) can download Afterburner to play around with it.
At the time of our testing it had also not been updated to support the R9 280X. It did at least see the card as an "R9 200 Series" product, however.
For the MSI Twin Frozr Gaming card we were able to push clocks from 1050 MHz up to 1150 MHz but I was only able to maintain a stable overclock at 1650 MHz memory. This is well under that of the ASUS card.
Sapphire TOXIC Overclocking
Finally, we have the Sapphire TOXIC R9 280X that already comes out of the box at the same clock speeds achieveable with the MSI card above. The Sapphire TRIXX works just fine but doesn't have the same bells and whistles of the ASUS or MSI options.
Still, the results kind of speak for themselves: I was able to push the TOXIC card up to a clock speed of 1225 MHz with a memory speed of 1700 MHz and run completely stable in our environment.
The result of this extra overclocking is a 3DMark Fire Strike Extreme score of 4266; nearly 20% faster than a reference R9 280X.