Im going to disagree here just on the side of mining though. I am a Redhat certified engineer (Earned RHCE earlier this year), and I work with RHEL6 and RHEL5 machines for a career. So I totally understand the subtleties between Windows and Linux.
But, there is absolutely nothing available that will allow you to overvolt a a non-reference GPU in linux. There are a multitude of tools for Windows that allows voltage adjustements for non-reference cards. Trixx, MSI Afterburner are just a few. AMDovrdrvctrl will not allow you to adjust voltages on non-reference cards. You also have to modify the BIOS ont the GPU if you want to do anything worth while with AMDovrdrvctrl. You dont have to modify the BIOS to do the same with the Windows tools mentioned above.
But, there is absolutely nothing available that will allow you to overvolt a a non-reference GPU in linux. There are a multitude of tools for Windows that allows voltage adjustements for non-reference cards. Trixx, MSI Afterburner are just a few. AMDovrdrvctrl will not allow you to adjust voltages on non-reference cards. You also have to modify the BIOS ont the GPU if you want to do anything worth while with AMDovrdrvctrl. You dont have to modify the BIOS to do the same with the Windows tools mentioned above.
The complaint was there was no way to overclock in Linux and that complaint is false. There was no mention of overvolting. Regardless, though, overclocking and overvolting via software is a ludicrous proposition anyway for anything but a temporary measure. I've never understood the trend, honestly. You get shitty results and a bucket load of instability in the long term when you do it via software, this applies to both Windows and Linux. The only thing software overclocking is good for is to find your stable numbers. Once you find those, you should flash your card with those and leave it at that. Software tweaking is a temporary measure and for the purposes of mining, it's completely pointless. If you're going to mine you need your cards to be set to what you're mining with. If you're some hobbiest miner that is only doing it now and again while using the computer for other tasks, then you're probably not going to be using Linux anyway. If you're following this guide then you most likely are serious about mining and have a dedicated box and thus using software to overclock for mining is just wrong on so many levels.
Not true. There are a couple different tools that allow Linux overclocking, which have already been mentioned in this thread.
Personally, I flash the BIOS with RBE and don't even worry about overclocking from the command line. If you can't overclock in Linux, the fault lies with the operator, not with the (lack of) ability. Is it as slick and easy as Windows? Nope, but then again, Windows can't do half the things a Linux machine can in terms of mining, so it's a trade off. I'd like to see you run more than 8 GPUs in Windows. Can you even run more than 4?
Personally, I flash the BIOS with RBE and don't even worry about overclocking from the command line. If you can't overclock in Linux, the fault lies with the operator, not with the (lack of) ability. Is it as slick and easy as Windows? Nope, but then again, Windows can't do half the things a Linux machine can in terms of mining, so it's a trade off. I'd like to see you run more than 8 GPUs in Windows. Can you even run more than 4?
My ASUS 5850 DirectCU 725 are virtually impossible to overvolt. GPU-Z cannot pull the bios from the cards. So I instead download a bios version that looks similar from guru3d. The bios works fine. After that I attempt to edit via RBE. No dice. Once I edit the voltage the GPUs are no longer recognized by aticonfig and/or windows. They are "greyed" out. Perhaps its user error in the RBE editor, but I sure as shit can't figure it out.
If I can find a 5850 for cheap, I'll pick one up and see if it's that much different than the 5870's. If you want to send me a copy of your stock BIOS I can take a look at it.
