There are many different tools that can be used to overclock video cards, Sapphire has a tool called TriXX. Using this tool we can adjust the Memory and GPU clock speeds, along with the voltage. In addition, if we want to manually adjust the fan speed we can do that within TriXX as well. The GPU clock and Memory clock was slowly increased by 25Mhz, between each increase Heaven 4.0 was run to verify stability. If Heaven completed successfully without any graphic glitches or lock-ups the GPU and Memory would get increased.
Starting with the boost speed of 940Mhz, we took a baby step to 950Mhz. With no issues, the GPU was slowly increased to 1075Mhz and the Memory to 1350Mhz. Unfortunately, even though Heaven completed successfully, when we increased the GPU clock to 1100Mhz the entire test bed shut down and refused to boot with the Sapphire Dual-X R9 280.
Just to verify that there was an issue with the card, all AMD drivers were uninstalled which allowed the test system to boot without any drivers, which it then booted successfully. As soon as the drivers were installed the screen would go black and wouldn’t come back. The Dual-X R9 280 was transferred to another test system, and the same results were found.
Overclocking Results: The Sapphire Dual-X R9 280 ran flawlessly up to 1075Mhz GPU clock speed, attempting to go a little faster to 1100Mhz resulted in the video card crashing and being unrecoverable. If you wish to overclock this card, I would recommend overclocking with care, and be aware that our review sample died after overvolting it and trying to get 1100MHz stable.