Undervolting & stability

[thewhat]

I'm undervolting an X2 4000+ (AM2) on an Asrock ALiveNF6G-VSTA. Using RMClock.

I went down to 0.8 GHz and 0.8V. Run it stable with LinX and Prime. (Even at 0.775V.)

But here's what's interesting: While it's stable in those stress programs, when browsing or moving windows I get a BSOD or restart.
Can anyone explain what's going on?
If I had to guess it would have to do with graphics.. but why would undervolting (underclocking) the CPU affect graphics?

 

[SlitheryDee]

It could be that AMD's version of turbo is kicking in when you stress test. That may include upping the voltage alongside increasing the clockspeed to a level that is able to run stably. While you aren't doing anything particularly stressful (moving windows around, etc.), it remains at the settings that you specified and it turns out that .8 volts isn't enough to run at .8 ghz, causing the instability.

That's just a guess. Someone with more knowledge should chime in here as well.

 

[richierich1212]

Don't use RMClock, try out PhenomMsrTweaker instead:

http://phenommsrtweake.sourceforge.net/

 

[universeis42]

AMD doesn't have turbo mode on any of their processors except Phenom II X6. How long did you test for? A couple hours or more is necessary to ensure stability.

Also try using K10STAT as another undervolter. Maybe RMClock adjusts offset instead of voltage for each power state.

 

[thewhat]

It could be that AMD's version of turbo is kicking in when you stress test. That may include upping the voltage alongside increasing the clockspeed to a level that is able to run stably.

Could be, but:
1. I saw no indication in CPU-Z of such voltage or frequency increase during stress testing
2. I now set it to 0.8V in BIOS and disabled CnQ and it works fine so far, both in stress testing and overall

But yeah, CnQ (or something similar) could have something to do with it. Or RMClock..
The only reason I had CnQ enabled was to make the RMClock scaling features work. (EDIT: now that it's at .8V and .8Ghz in BIOS it seems to be working even with CnQ off.. hmmm.. I'll do more testing)
I need frequency scaling based on CPU load.

Don't use RMClock, try out PhenomMsrTweaker instead:

http://phenommsrtweake.sourceforge.net/

I don't have a K10 CPU, the program wouldn't run.