|HIS Radeon HD 6870 IceQ Video Card|
|Reviews - Featured Reviews: Video Cards|
|Written by Steve Hearst|
|Wednesday, 09 November 2011|
Page 17 of 18
HIS Radeon HD6870 IceQ 1GB Overclocking
Before I start overclocking, I like to get a little bit of information. Firstly, I like to establish operating temperatures and since we know the IceQ cooler is quite capable we can quickly move forward. Next, I like to know what the voltage and clock limits are, so I fired up the MSI's Afterburner utility. I established that vCore was adjustable between 800mV and 1.30V. Clock speeds were limited to 1000MHz max on the GPU and 1250MHz (5GHz effective) maximum frequency for the memory. This is more than enough range to move forward with and I know I can squeeze every last drop of performance out of the HIS Radeon HD6870 IceQ 1GB. My preferred weapons are MSI Afterburner (v2.2.0 Beta 8) for fine tuning while using FurMark (v1.9.1) to heat the GPU.
More overclocking headroom could be unlocked for the GPU Core and Memory speeds using the unofficial overclocking method in MSI Afterburner, but I wasn't able to keep this card stable during testing when I went past the previous limits. I bumped the vCore to the max 1.30V and was able to push the clock speeds to 1000MHz GPU and 1250MHz (5GHz effective) Memory and still remain stable during the benchmarking run.
With a 100MHz GPU overclock and a 200MHz memory overclock we went back to the bench and ran through the entire test suite. Overall there is an average 14.13% increase in scores (at 1920x1080 resolution). We also re-ran temperature tests at the overclocked speeds with an ambient temperature of 25°C. The IceQ cooler on the HIS HD6870 IceQ 1GB once again pulled through and gave some decent temperatures. At idle the GPU sat at 46°C (49% fan speed). Pushing the temperature up with FurMark saw the GPU load temperature rise to 78°C (76% fan speed) and cranking the fan on manual to 100% saw the temperature drop to 74°C.