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I think I have bought the wrong PSU...

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June 30, 2010 7:20:57 PM

Hey all, I recently put together my first computer. Everything was running great until I put the graphics card under any sort of strain. The monitor would turn off after about 20second - 1 minute. I have a http://www.ebuyer.com/product/135159 PSU which runs an amd phenom x 4 955, and a single hd 5770 card, as well as 4gb of ram.

I am fairly sure this is the problem, after doing everything I could think of: updating drivers, plugging card directly into psu (had been using the adaptor), ect. I then read i need 40Amps for each 12v rail. I will be honest and say I am not too confident with PSUs, so I may have bought a poor one. Looking at the side I think I only get 18A per 12v.

What do you guys think? Could it be something else?

Thanks

More about : bought wrong psu

a c 272 ) Power supply
a c 194 U Graphics card
June 30, 2010 7:24:03 PM

That unit should have plenty of power for the 5770, its a low power draw card. A good 500-550 has about 40A between its 12V rails, if you have two rails 18A on each its alright, you dont need 40A on each rail.
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June 30, 2010 7:25:29 PM

oh.. oh. So what's my problem do you think?
a c 272 ) Power supply
a c 194 U Graphics card
June 30, 2010 7:32:47 PM

Get something to monitor your temps like HW Monitor, then use furmark and prime95 to load up your CPU and GPU. First do each one alone, then do them both at the same time, when you are doing them both at the same time you will be at max possible power consumption so if you are close to your PSUs limit this will cause it to shut down. There is also the possibility that you might be overheating and causing an auto shutdown, running them will also help you find the max temp your components hit.
June 30, 2010 7:35:03 PM

Thanks! I have indeed already tried that, and my cpu ran for a fair time reaching just under 60C without any power problems, however using furmark on my gpu causes it to crash. The temperature will rise rapidly to about 80, and slowly reach up to 90. however it sometimes crashes at 75C. If it's an auto shutdown, how can I find out when its programmed to do that?

Thanks again
a c 91 ) Power supply
a b U Graphics card
June 30, 2010 7:37:01 PM

Try using the other port on your video card for connecting to the monitor..
June 30, 2010 7:38:00 PM

It has only one port, unless you mean the integrated graphics card?
a c 272 ) Power supply
a c 194 U Graphics card
June 30, 2010 7:38:46 PM

Your GPU generally wont have the ability to auto shutdown the system, if running furmark alone can cause your system to crash then you were right in thinking it might be a power problem, i would put my bet on either a GPU issue or a PSU issue. Do you have another PSU that you could use to test your system with, or someone who would let you test your 5770 in their system to see if its at fault?
June 30, 2010 7:39:58 PM

I could test the 5770 (not 4870) in my older computer, however I have no idea if that will work at all, do you think that's the best next step?
a c 272 ) Power supply
a c 194 U Graphics card
June 30, 2010 7:42:25 PM

Yeah, i would consider that the next best step. If that system doesnt crash while running furmark then you can rule out it bring a problem with the card.
June 30, 2010 7:43:01 PM

ok thanks, I will try that! Will let you know the results
June 30, 2010 8:43:37 PM

Ok, I think I have ruled out faulty GPU, however it has made me ask many questions. I ran the gpu on my old pc, which is a miracle in itself soon as its a packard bell stock pc, with somehting like a 250w power supply, and I was a lil worried about temps as they approached 100C very very quickly on furmark. So I downloaded the catalyst tool, put fan up to max settings and ran it again for about 3 minutes. There were no problems whatsoever. However I was unable to test for much longer as I was seriously concerned about temps, they had once again reached 100C+. However I ask:

How come my GPU could run on a much much worse PSU?

It is definetly not shutting down due to overheating, as it only reaches 80C on here, max. So what is it?


I am swaying towards faulty PSU... any otherthings I should test?

Thanks
June 30, 2010 8:44:32 PM

Running for 3 minutes doesnt absoloutely count the GPU as ok, as it had run for that long before... but I dunno, maybe I should try the furmark test on here yet again?
June 30, 2010 9:07:53 PM

Ok retried it, same think furmark froze solid after less than a minute. Fortunately I could ctrl alt delete quickly and it eventually came up with a display driver recovered error. Dunno if thats helpful
a b ) Power supply
a b U Graphics card
June 30, 2010 9:42:34 PM

It sound to me that you have an overheating issue on the 5770 and should return it to default values (Set motherbd clocks back to default also), check the gpu and make sure the fan is spinning and theres heat sync compund on it (I once got a card where they missed putting some on), or exchange it if its still under warranty.
June 30, 2010 9:45:23 PM

hey thanks for the reply, I have not overclocked it at all so I cant see that being the problem... I am thinking of returning it but like I say, it seemed to work on another pc...
July 1, 2010 9:44:27 AM

Ok heres an update. I tried it yet again in the other computer, it seemed to work fine. However I noticed, even in a case without any additional fans, it heated up a lot slower. I tried it in a different pci slot on my new computer, and although this seemed to fix the locking up problem, it did two new things. 1 it is further down the case so it heats up a lot faster, up to 108C... which I know is wayy too high, especially considering I had the gpu fan at 100%!!!!!!!!! There is some kind of issue here... could it be that one of the computers was reading the temps wrong? I am using furmark to check it.

Also after 3 minutes on my new computer, the fan that was at 100% went off.. or no not off, back to default settings.. however when I then closed furmark it went up to 100% again...

I'm baffled.
July 1, 2010 10:16:48 AM

Ok this really is getting weird. I am now fairly sure that the problem was with the other pci-e connection... however the temperatures in this other one are much higher... 105C with case side off. I would say with 100% fan but thats the other problem, the fan goes off about 1 minute into the furmark test.


So update:

Fixed monitor going off

temps wayy too high even with case side off

eratic readings on furmark and other temp reading software... the graph on furmark was like^^^^^^ in other words up down jumping between 104 and 108C..


Any suggestions?
July 1, 2010 1:22:32 PM

Describe all the cooling on your system, input and output fans, sizes, RPM's, CPU cooler, etc.
July 1, 2010 2:46:48 PM

what psu your gpu supports ?
July 1, 2010 6:32:19 PM

Ok I have got my psu 500w, not sure of fan speed, but there is one on side and bottom, I have an 80mm fan on the back of the case, the front has a fan which is built into this case http://www.ebuyer.com/product/146271 . I have also just bought a pci fan that uses 2 80mm fans, and of course the CPU fan....

I still reach 100C on furmark max settings, but it takes a litte longer. Is it possible the card is broken?
!