If we were holding a reference version of HD 7970 where GPU runs at 925MHz and memory at 1375MHz, we’d be quite content overclocking the GPU by 175MHz (almost 19 percent). However, we’re talking about PowerColor’s PCS+ HD7970 Vortex II graphics card that already boasts a 175MHz overclock.
Many HD 7970 graphics cards may falter before reaching 1100MHz, but PowerColor made a careful selection ensuring that only the crème of the crop GPUs end up in their cards running at 1100MHz+. The “+” is here because we managed to overclock the card even further.
PCS+ HD 7970 Vortex II graphics card comes with dual BIOS and we’ve seen that both include the factory overclock. You can use the second BIOS during overclocking and revert to the first BIOS in any case of trouble.
We managed to push the GPU to 1175MHz and we couldn’t do better regardless of upping voltages or speeding up the fans. So, we managed to hit 1175MHz GPU and 1600MHz for the memory with default fan and voltage settings defined in VGA BIOS. We must say that this is an excellent result. Thermals were good even after our overclocking and the fans were pretty quiet, but more on that on the next page.