Does Voltage under/over clocking help raise hashes?

[PandaMiner]

First of all, I have an XFX 6870, which they say leaves very little wiggle room to overclock.

I was able to unlock the core Voltage slider, which currently shows 1174 mV (1.174 V)

My system freezes at core mhz over 950, no matter what my memory is clocked at.  (which, btw, only goes DOWN to 525mhz)

Where can i read up on messing with the voltages in regards to core hertz?

Thanks for your time.


Stock: 225 Mh/s
GUIminer with [-v -w128] flags:  255 Mh/s
GPU memory @525mhz:  270 Mh/s

[stellan0r]

i actually have two xfx 6870 black edition and ran into some trouble lately (after messing up my driver installation and even completely redoing the system and setting up fresh drivers )

so until 2 days ago i had them running in crossfire mode with msi afterburner set to 1050core/300memory, no voltage adjustment (+ an additional 5870 at 950/300 with stock voltage).
if i try this now, it does not work, the system freezes right after hitting the apply button in afterburner or after a couple of seconds when i start mining.

i have tried catalyst 11.5, 11.5b and 11.6. I would really love to hear ideas why it now does not work, while it did work a couple of days ago.

also tried afterburner 2.1, 2.2beta3 and beta4 (which runs fine at lower coreclocks right now).

i must also say, that with 1050/300 my system used about 50 watts less then now (1008/575)!

If anyone knows more about working voltage settings or what voltage increase helps stabilize the system...

[PandaMiner]

I'm having a similar problem.  Even now when I revert to stock clock, but lower memory, it freezes upon clicking the apply button (if miner is on) or just after [start mining] is clicked.

My next thing is to unedit the EULA changes.

[stellan0r]

i had freezes even when changing the fan setting at stock clocks ^^

[PandaMiner]

Maybe its the program.  MSI AB.  :-/

[stellan0r]

the question is, why does it work one day, and fails the other?!

i already eliminated one point of failure regarding the amd ccc, as this seemed to happen to me several times:

http://support.amd.com/us/kbarticles/Pages/ATICCCInstallFreezes.aspx

the Microsoft .NET Framework also seems to make trouble to some of us, too, if you read the support articles from amd