Computer shuts down on heavy load

[markb_in_fla]

Hello all, new to this forum,
Here's my problem, When i run games or a stress test the computer shuts down, doenst BSOD, just completely shuts off. Is this a power supply problem?, I am over clocked (see below). Any suggestions would be welcome.

Here's my spec's:
AMD Phenom 720 X 4 (unlocked 4th core)
multiplier @ 17.5 = 3523 Mhz cpu @ 1.53v
4 Gb G Skill ram
Gigabyte Ga-Ma790x-ud4p Bios rev f5
Corsair 650 watt power supply
Nvidia GTX 260 896Mb

 

[obsidian86]

does it bsod with only 3 cores?

 

[jsc]

If your PSU is working properly, you have more than enough power capacity. In fact, your system should be able to be powered by a good 550 watt PSU.

First thing to try is to borrow a known good PSU of similar (or better) capacity.

 

[outlw6669]

...
AMD Phenom 720 X 4 (unlocked 4th core)
multiplier @ 17.5 = 3523 Mhz cpu @ 1.53v
...

The fourth core was disabled for a reason.
Enabling it then pushing a massive (for a first generation Phenom) overclock on it is not recommended.
I seem to remember most true Phenom x4 CPU's having difficulties getting past 3-3.2Ghz stably.
I doubt you will get yours even that high stably with the rejected fourth core running...

Disable the fourth core and back off the overclock until your system becomes stable.

 

[markb_in_fla]

It has been running with all 4 cores stable (six hours of prime 95) for 3 months, just within the past fews days its been acting up. No BSOD.....just powers off, but can boot right up with no problems

 

[JDFan]

Are you using the Stock HS\fan that came with the Chip ?? - If so at that OC with the 4th core it is probably overheating (mine is running stable with the 4th core at 3.0Ghz. but I do not push it anymore right now because I do not have my aftermarket HS yet so it is running a bit high on the temp (nothing near shutting the system down but high enough I don't want to go further with) at that setting under stress (the stock cooler is just not up to the job with the extra core and the extra Mhz. ) So if you are on the stock parts I'd say it was definitely the Temps.