Hi

I have a computer like this

athlon x2 3800 oced at 2.3ghz
biostar tforce 939
elixir 2x512 mem

I used to do encoding like this always but today every time i do encode video with you name it (convertxtodvd, tmpenc, winavi) and they use both cores (multithreaded) at full 100%, then the pc just shuts down after a pair of minutes it started encoding. the temp is at 45, so its not a heat problem.

BUT if i run them with normal settings (NO OC) it works just fine, or if i use a program single threaded i works fine even overclocked because they only use cores at 50%.

could this be a CPU problem, Power suply or mobo problem?

thanks.

What is your power supply?

It could be many things and you havent listed enough details of hardware and your oc.
you cant set the clock and walk away .
downlaod prime 95 and burn both cores adjusting Vcore ,memory voltage and timings until stable.
Like stated above your psu is not listed so its not a fair troubleshoot without more hardware specs.

I'll agree with the guy above.. uh to me it appears to be a PSU problem; I had a similar problem before where my 12v rails dropped too low(around 10.5v?) when my cpu/vid card put on load ~75% and reset or turned off completely...

I would be more inclined to say that one of the cores becomes unstable at the overclock you have. A lot of times you'll have one core being stable at a higher speed than the other and that can cause problems if the unstable core is fully loaded.

Ok I forget to tell you I have a 450w PSU. the problem ONLY comes when OCed(automatic 15%), at normal speed it works like charm.
I used to have it OCed for about 6 months until now, i guess either the cpu does not tolerate OC anymore or my PSU is failing.