HIS HD4870x2 Overclocking + Rivatuner 2.11
Prior to Rivatuner 2.11, overclocking a HD4870x2 required using Catalyst Control Center (CCC) to properly clock both GPU cores and for you to clock past it's reference ATI bios preset CCC GPU/MEM limit of 800/1000 would of needed to use modded bios or obtaining the Asus HD4870x2 TOP bios which had a higher CCC GPU/Mem limit 900/1000.
But Rivatuner 2.11 has a new pair of power user features which allow to overclock both GPU cores within Rivatuner 2.11. These 2 power user features are EnableClockControlCloning and EnableFanControlCloning which you can find and enable via the Power User tab.
Then to properly overclock the HD4870x2 past the CCC preset limits, you need to either uninstall CCC or as I did, disable CCC from loading by running
msconfig and unchecking CCC from start up process and reboot system for it to take effect. I found if I didn't disable CCC then overclocking via Rivatuner 2.11 would only overclock the GPU core clock on the first core on HD4870x2 past the preset CCC GPU clock of 800mhz, but 2nd GPU core would stay around 800Mhz max.
Once done, you can begin to overclock your HD4870x2 without the annoying CCC app by using the Low Level System Settings options available as pictured below.
Personally, when not overclocking to the max, I've custom set my HIS HD4870x2 fan speed to 45% at start up and with 500/500 underclocked value and ramp it up to 100% fan speed for higher GPU/MEM clocks when overclocking.
This keeps my GPU/MEM and shader core idle temps well below 50C at around 44-47.5C once in windows.
Note: - when setting clocks, each time you set a clock it will revert the fan speed control to AUTO instead of FIXED, so you need to reset the fan speed each time you set a new GPU/MEM clock setting
- when you set fan speed to 100% the first time, it will auto reset to around 62-78% so you need to set it a 2nd time to 100% fan speed for it to stick
So now you can overclock HD4870x2 without needing CCC past the preset GPU/MEM limits in reference and Asus TOP versions' bioses using the overclocking features of Rivatuner 2.11. If you do need to use CCC to adjust other options, you just need to re-check back the CCC start up process via msconfig once again and reboot your system
How much further past the CCC 800/1000 limit can I now overclock you ask ? Well preliminary tests for my HIS HD4870x2 is I'm easily benching at 860Mhz GPU core ! Memory has yet to be tested.
Quick benchies at low cpu clock of 4800Mhz with HIS HD4870x2 @860/900:
- 3dmark06 = 23,459
- 3dmark vantage = 14,289
- 3dmark2003 = 92,170
