My PSU MAX output is 350 yet is running 450 MINIMUM card??

Sadistt

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Jun 17, 2012
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Hey guys, I'm looking to replace my NVIDIA GeForce GTS 240 (card broken or something, keeps overheating when cleaned HSF + thermal paste, idles at 70~80 degrees and goes over 100 easily under load which crashes computer with black screen) with EVGA Geforce GTX 550 Ti and I noticed that the requirement for the GTX is 400 W minimum, and since my GTS 240's requirement is 450 W I thought I didn't need to replace my PSU until I actually looked inside and saw that my PSU caps at 350 W. What the hell is this? How is it able to run a card that requires 100 more power than what my PSU can output? I understand that they overrate the card's power requirement but still, a 100 W in difference?

What's going on? And since the GTX's requirement is lower than my current GTS, can I still use the same PSU?

My PSU came with my Dell Studio 540. It's "bestec atx0350p5wa"
Just in case it matters here's my spec:

Windows Windows 7 Home Premium Edition (64-bit)
Memory (RAM) 4096 MB
Intel(R) Core(TM)2 Quad CPU Q9400 @ 2.66GHz
NVIDIA GeForce GTS 240
Motherboard: Dell Inc. Model: 0M017G
 
check the cards TDP. A GTS240 is 120W a 550ti is 116W.

That PSU is actually listed as 400W so I'd not be surprised dell used it, but its only got 190W on the 12V rail so I would definitely not. and that's before you consider its age. if it didnt come that way from dell and the original card was added id say you got very lucky nothing blew. This type of issue is exactly why manufacturer recommendations are so high. Everything that really matters is on the 12V, and PSU makers are dishonest at best
 

Sadistt

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Jun 17, 2012
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Uhh, sorry what? Can't understand what you're saying. What's exactly the reason I can't run 550 when it has lower req than 240? again?
 


like I said you are running a 95W CPU and a 116W (so 211W plus the motherboard) on a 190W PSU. And as PSUs age they loose capacity. You've been lucky so far. it might work. it might explode and take everything out with it. it might explode in a week. or a month. or die quietly in its sleep.

I personally would not even consider turning it on with that PSU, even though nothing bad will probably happen till its stressed.
 

erunion

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Apr 14, 2011
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The recommended power supply wattage is not how much power the card draws. The recommendation ensure that your PSU will have enough for your other components as well. As unksol said, the video card draws power from the 12v rail so its actually that number that is the most important.

If you can run a GTS240 without problem then there is no reason you shouldnt be able to run a 550ti.
 


At issue is what's comming up in Google as the rated 12V wattage for that PSU Since this number is often much lower than what they put on the advertising. But its late and I need sleep. Found another post

saddist look here
www.tomshardware.com/forum/293393-33-5570-5670-5770-350w-bestec

the +12V numbers are what you care about. if they match those its 300W not 190W and you're fine. not sure what's with these other spec sheets. maybe its a knock up coming up or they dropped a rail on it accidentally
 

Sadistt

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Jun 17, 2012
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I'm not running a 550ti right now, which is why I posted the question. Are you saying the GTS 240 will explode in the future? And could PSU aging be the reason why my GPU is overheating when it's spec clean?
 

Sadistt

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Jun 17, 2012
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yes that's the one that I have, so I'm good to go?

And in case it's not, what's the worst possible scenario that can happen when I replace the GPU to 550?