CPU Voltage Fluctuates

[php_wizardry]

I have a phenom ii x3 720 on a ta790gx 128M ver 5.x motherboard. On default and overlocked settings my cpu vcore voltage goes from 1.47 to a 1.1 under load. When its not under load its back up to 1.47. But when I run prime95, its drops big time, causing my system to crash. Any idea how to fix this, without replacing something...thanks in advance.

 

[saaiello]

That is one of two things either its a really bad case of VDroop or your PSU isn't able to handle the extra load.

 

[jsigur]

yes, some motherboards have v-droop control and this is something thqat has to be enabled in the bios.When there is no v-droopo control, you have to set your cpu voltage .5 volts or so above what it needs underload,. V-droop is a protection device for the motherboard but many overclockers buy mobos that cazn disable it

 

[roonj]

On another angle just out of curiosity, that cpu defaults @ 1.325v yet you say 1.47. Does that mean you raised the volttage for your overclock?
Also since the sensors either internal/cpu or motherboard temp throttle the chip back when overheating (by lowering voltage) would this indicate C1E is turned on or cooln'quiet is still on. Been too long since I read that material to remember which method is used but I thing it's voltage drop.?
I have this feeling someone's going to say vdroop is voltage throttle back.

 

[lordszone]

I have a phenom ii x3 720 on a ta790gx 128M ver 5.x motherboard. On default and overlocked settings my cpu vcore voltage goes from 1.47 to a 1.1 under load. When its not under load its back up to 1.47. But when I run prime95, its drops big time, causing my system to crash. Any idea how to fix this, without replacing something...thanks in advance.

Hi
I think the voltages are set to auto, if you set them to a specific value then i dont think the voltages would fluctuate. and i think your psu is weak. hope i helped.

 

[jsigur]

Hi
I think the voltages are set to auto, if you set them to a specific value then i dont think the voltages would fluctuate. and i think your psu is weak. hope i helped.

voltages fluctuate underload. Motherboards that disable v-droop, make that fluctuation less, sometimes in the case of my Rampage 2 with bios revision 1804, they can raise the voltage underload. Just learn your mobo's particular habit in this area.