PC restarts non stop unless I overvolt at stock settings :S

[the associate]

I've had this am2 6400+ for a few months now, and ever since I got Vista 64 I had restarts ranging from 5 to 60 minutes apart. That was because of undervolted ram.
Now everytime my pc would start to load windows, it restarts. My cpu's stock volt setting from what i've been able to pick up on is 1.4 volts. When I up it to 1.45 the restarts stop. Why does my spu suddenly need an extra 0.05 volts?? I have the same issue on both my psu's, thermaltake toughpower 850w mod (which i exchanged for another when I got this issue since recently bought, same problem with 2nd one) and an Antec 850w TP Quatro.

In bios and with OCCT it reads my cpu running at stock speeds, so thats not the problem, maybe I have a crap cpu? or is it just that their all crap (amd cpu's in general).

 

[calinkula]

Not sure what your mobo is, but if it has a big V droop you would see such voltage problems.

 

[Superhal]

check the memory using memtest86.

get cpuz and click on the "spd" tab. that will tell you the manufacturer's suggested settings for that chip.

if it's ddr2, 1gig, 800 mhz, the minimum voltage is 1.8v. 1.4v is way too low. on mine, it's usually 2.1v or higher.

you can estimate psu wattage at: http://extreme.outervision.com/psucalculatorlite.jsp

also, you should always list your mobo make and model. there are many known issues that this could be, e.g. Asus bios always sets the voltage too high for phenom chips, which causes random freezes and reboots.

 

[br3nd064]

@Superhal: 1.4v is talking about the cpu voltage, not the ram voltage.

I agree with Calinkula, it does sound like Vdroop.

 

[the associate]

After running OCCT for 2 hours my cpu voltage is stable, never drops.
As for my ram, it's running at OCZ's voltage recommendations of 2.1.
It's weird because my pc NEVER screws when in heavy use (benching, OCCT, games)
The restart happened to me once since I uped the voltage 0.05, maybe a voltage glitch involving capasitors or power transfer management issues with the board during startup only somehow? :S

This is my cheesy mobo
Gigabyte GA-MA770 DS3
Replaced nb heatsink with a bigger+better one, and put little zalman sinks on those fat cubes near voltage regs since they burn to the touch.