Is this a sign of my graphics card failing?

[Rubidoux]

Here's my setup:
EVGA GTX 460 SSC+ 1GB
AMD Phenom II x6 1055t
MSI 870A-G54 mobo
4GB GSkill Ripjaw 1600 DDR3
Rosewill RP600V2-S-SL 600W ATX12V Power Supply
Some 23" HP LED backlit monitor I managed to find in some half price desktop bundle, don't know model off hand.
22" Samsung P2250 Syncmaster monitor

All of this was bought around February this year.
What's happening is if I play anything that's pretty heavy on graphics, Crysis 1 and 2, RIFT, etc etc. I'll be playing and all of a sudden both my monitors go into sleep mode, and my pc sounds like it's slowing down. It remains on, but there's no display, a little LED will flash on the front of my case, and I won't be able to turn the power off using the normal power button, even if held down, I have to flip the switch on my PSU. If I just use the pc normally for regular browsing and what not it will last for as long as I need it to, but soon as I play some heavy games for half an hour (Sometimes it happens instantly, rare though) it'll happen. Now I don't all the much about PCs, I know enough to build one and that's it (Not saying much), so I want to know, does this sound like the graphics card is just failing? Is it getting too hot? PC Wizard never showed it as getting too hot, but if I immediately restart after the sleep thing it won't boot, so I wonder if it needs a few to cool off or what.
Another friend of mine thought it may be the PSU or Mobo, and I have no idea how to test any of that, so I'd like to get some opinions who deal with these things a little more frequently. Thanks

 

[zodiac321]

it could be your PSU, from what I've heard, bad PSU brands don't exactly give out all the power they say they do. I can't say for sure, becasue I have a 1000w Roseill, and it powers my PC effectively,

 

[Rubidoux]

Browsing around the reviews for my PSU, I noticed everybody was complaining about the low Amp on the 12v rails. I don't really know what that means, but could that affect it? Overall it has quite favorable reviews, had 425 5 ratings on Newegg, averaged out over 4 so it can't be that bad.

 

[Helltech]

I would venture to guess its that Rosewill PSU.

Two things you can try... Try a different PSU in your system, try your GPU in another system.

 

[JAYDEEJOHN]

Your 12 V is what youre gpu needs for power
Some PSU makers make huge claims on numbers, like 40 amps, but thats added for each type of voltage on the cheaper/bad PSUs
Say 10 for the 3.3 volt, 10 for the 5 volt and 20 for the 12 volt lines.
And many times, you cant even get 20 amps out of the 12 volt lines either.
Id say its your psu, the sooner you find it out, the better the rest of your componants will be

 

[davcon]

Yep! more then likely it's the psu which i've seen linked to similiar problems on this forum.
It's an ATNG oem which isn't exactly a first rate psu maker..
Also a rather outdated model by today's standards
+3.3V 30A /+5V 55A /+12V1 19A /+12V2 19A
The first two rails Amps are a dead giveaway it's an old outdated design.
Reason why most of us here always recommend not to cheap out on your psu.

 

[_Pez_]

I would say that's a syntom of a hot graphic card, I used to have the exactly same issue with a gtx285 SC, monitor turned off, pc still powered on and when re-turned on won't it boot, until Gpu was cooled.. and it may be caused because it is an SSC Super-super-cloked. so you should understeand why.. maybe the gpu or memory chip's or another electrical part of the graphics pcb gets to hot and need to be cooled, until then it boots again. I wouldn't complain about the PSU because my computer has been working with a 1200 Watts thermaltake sli certified and 80 plus certified, and that issue was there, now my computer has 2 gtx580 SLI and the gtx285 as physx card and there's no issue anymore. The way to fix that is raising the rpm of the cooler, you can do it manually with EVGA Precision. Fan monitor. Try this and let me know if it changed.

 

[_Pez_]

I forgot to say.. If you keep thinking that your PSU might be the problem check this link of toms H. and see by yourself if your psu "sucks".. http://www.tomshardware.com/reviews/power-supply-oem-manufacturer,2913.html

 

[Helltech]

We already know who makes that PSU, its ATNG.. and no they aren't great by any means.

 

[JAYDEEJOHN]

Those 19 amp 12v rails is no higher than my old 420 watt Enermax
Thats alot of rig to be runnin so skinny

 

[Onus]

The PSU is an older, inefficient, overrated design; the little voltage switch gives it away. Please replace it before the unpredictable voltages it delivers as it shuts down damages some other part of your rig. Seasonic, Antec, Corsair, Enermax, and XFX are among the better brands. A quality 500W PSU is sufficient for your build. Expect to spend a minimum of $60-$80 on a decent one like an Antec Earthwatts; twice that for a really good one like a Seasonic "X" series.