I've just started getting a strange problem with this motherboard. First some background.
I've upgraded the chipset cooling (NB and SB) with the idea of trying for a better OC (current OC is 2.65GHz - has been stable for over 1 year). This is no longer my primary system so a good learning opportunity.
There is a setting in the bios for this board to 'Overvolt CPU vCore'. I earlier read on the Corsair support forum that you could activate this and it would result in a 0.2V increase in vCore and enable 8-phase power. The enabling of 8-phase power was a bit of a surprise as I thought it would always be enabled. However, I decided to give it a try. So, I enabled it and dropped my vCore down to 1.20V (previously was set at 1.3875). Checked in WinXP using SpeedFan 4.32 and all seemed ok - vCore was reporting around 1.41 (was previously reporting 1.44v) with vDroop down to 1.39v under load (previously 1.41v). Everything is stable (Prime95 and Memtest) and my CPU temps have dropped by around 3-5C under load
However, since enabling this, the pc will no longer power down. This also happens when trying to restart/shutdown from windows and when saving changes from BIOS. I can see that the memory powers down (Corsair 3500LL Pro with LEDs - which stop flashing), but the fans just keep on going and restarts never restart
Has anyone else experienced similar problems?
I'm reluctant to go back to my previous settings as I believe I can push the OC further from this starting point.
Full system spec (more or less same components running stable at same OC for over 1 year):
Opteron 170 @ 265 x 10
Asus A8N32-SLi Deluxe (HR-05 heatsinks on NB and SB; HR-09 on Mosfets)
2x1GB Corsair 3500LL Pro @ 2-3-2-5 220MHz (CPU/12)
XFX 7800GTX Extreme (Factory OC)
2x74GB Raptor (Raid 0)
400GB Seagate 7200.10
Edit: oops - it seems that it will power down if shutdown from WinXP, but not on restart (either from WinXP, BIOS, or Memtest) :?
I use the same motherboard and have had similar problems. The answer may be in your description of the voltage changes and temperature drops.
You did not get the full .2v increase that you expected from the use of the overvolt feature. Try increasing the setting until you have at least the same measured voltages as before the change.
OPTERON 165 @ 9x325 ( current setting )
FREEZER 64 PRO / CERAMIQUE THERMAL COMPOUND
1GB GSkill DDR550 @ 2.5-4-4-7 /11 divider (266mhz)
v-core set @ 1.45
2X GIGABYTE 7900GT IN SLI @ 551 CORE 776 MEM
HT LINK 1300 ( 4X SETTING )