Overclocking the EAH4870 TOP
We used ATI's Overdrive utility in the Catalyst Control Center to overclock the already overclocked EAH4870 TOP. We usually recommend that users just stick with the factory overclocks, but that didn't stop us from seeing what we could squeeze out of this card.
After the usual trial and error process, we hit a ceiling at 850 MHz for the core and 960 MHz for the memory. Recall that the factory overclocks are 815 MHz and 925 MHz, respectively, while the ATI reference clocks are 750 MHz and 900 MHz, respectively. The 100 MHz boost over the reference core speed is pretty impressive. Unfortunately, not all of the games we tested benefitted from the overclock, but you can see some of the test results at the new speeds above.