Overclocking 6870, 1Ghz @ 1.17v so far...

Well I finally decided to overclock my HIS vanilla 6870. It's about as reference design as you can get so I wasn't expecting anything special, although it is under water and runs VERY cold With stock clocks and voltage (900 core, 1050 mem, 1.175v) it idles around 35C and 15min in Furmark barely gets it 43C so I figure I have a lot of headroom.

The one thing I am having a lot of trouble with is finding a good overclocking utility that doesn't have a 1Ghz core clock cap. MSI Kombuster and Catalyst only allow up to 1Ghz core and thats no fun.

I saw a lot of people struggling to reach 1Ghz so I gave it a try and the little beast took it just fine and at stock voltages too I haven't bothered pushing the mem until I max out the core. Anyone have a download for Sapphire TriXX utility? The site is currently down...

Well so far no luck using RivaTuner 2.24c. I've used it before with all my other cards but it wont work with my 6870 for some reason. When I click "customize..." on the first tab where the overclocking options are the button is missing. I might try reinstalling drivers or something. Anyone have any other software suggestions?

Searching I found this Guru3d

See full thread. Apparently it is a bios block, and a custom Bios is needed.

GL

Well run Furmark for ~15 minutes before you say that it's stable. I've had mine set to 1000/1250 and it ran 3dmark06 fine with no artifacting or anything, but once I opened witcher 2, display drivers stopped working. Same with furmark after ~10 minutes. I'm at 960/1145 right now crossfire. (wtb higher clocks)

I think the only way to increase the limit would be to mess with your cards bios. I can't remember the program that I have at home (at work atm) but it allows you to create a bios for an ATI card, and you can set the limit that overclocking utilities can reach. It's one of the more popular ones that's used to backup your bios as well.

Hmmm I was afraid I'd have to do a BIOS mod. That's okay though, I got to know RBE very well with my 4830 xD I'll post some results in a bit.

Wow! Well thats convenient. I grabbed my BIOS using GPU-z loaded it up in RBE and RBE gave me a message basically saying it "fixed" RiveTuner to work with my card! Lets see if it'll let me go past 1000Mhz...

sexy. Good luck sir!

Well unfortunately RiveTuner still refuses to let me play with clocks and there is a huge storm here making the power surge (the power is notoriously unstable around here as it is) so no BIOS swapping tonight. I don't want to risk having the power go out during a BIOS flash...

Well I decided to test out the memory OC and the max software settable 1250Mhz was easily obtainable. I ran FurMark for a good 20 or 30 minutes and the GPU die temp reached 44C. I'd say there's a lot left in it Now to slowly and carefully BIOS OC...

Well I just had a bit of a scare... I found a little feature in RBE for changing the key-protected values of max settable core and mem frequency and I decided to change them. If it were to work then I'd be able to do all my OC'ing through software and not be forced to keep reflashing the BIOS. But... after attempting the flash Windows started BSOD'ing right before the login screen. So I had to pull out my card use the iGPU to get into Windows using the low-res boot option, uninstall CCC + drivers, reboot and into Windows, reflash the BIOS to stock, reboot, reinstall CC + drivers, and all fixed.

I don't see much of a point going past 1000Mhz core and 1250Mhz mem so I will leave it there to avoid bricking my card lol

Dooms101 said:

Well I just had a bit of a scare... I found a little feature in RBE for changing the key-protected values of max settable core and mem frequency and I decided to change them. If it were to work then I'd be able to do all my OC'ing through software and not be forced to keep reflashing the BIOS. But... after attempting the flash Windows started BSOD'ing right before the login screen. So I had to pull out my card use the iGPU to get into Windows using the low-res boot option, uninstall CCC + drivers, reboot and into Windows, reflash the BIOS to stock, reboot, reinstall CC + drivers, and all fixed.

I don't see much of a point going past 1000Mhz core and 1250Mhz mem so I will leave it there to avoid bricking my card lol

Click to expand...

Mind telling us what voltages you used to get 1ghz? I have 2x MSI R6870 hawk edition cards i'd really love to push to 1ghz