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Graphics card upgrade- PSU/power problems!

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September 3, 2009 9:11:55 PM

Hi all,
Recently I upgraded my graphics card to an Nvidia 8800 GTS, which I bought off a freind. I know its not the best or newest GPU, but its a good temporary solution for now. The problem is, when I had it installed, the computer repairs shop told me I would need a new PSU to provide the correct rails. So I had the PSU replaced and the GPU installed. Everythign works perfectly, apart from a few things.
The PSU WAS making a strange 'electric' sound a few days after it was installed, but that seems ot have gone now. The other problem is that when I run a graphics intensive game (or the high detailed objects in 3D modeling programs) a fan in the computer (maybe all of them im not sure) slows down. I can tell this due to the decrease in pitch of the fan noise, which is very noticable. Would it even be possible to slow down the fan due to a too heavy load?
The PSU is a jeantech ATX 405W, which supplies power to:
AMD phenom quad core 2.2 ghz
Nvidia 8800 GTS
4GB DDR2 RAM
500 GB HD (not sure of the make)
On board sound card
DVD-R/W (not sure of the make)
Those are the main components, but knowing me I have forgotton a few small ones somewhere (USB etc) Sorry for the vagueness- I dont have the computer infront of me at the moment
So! The real question- Is the PSU good/powerful enough? I've heard of stories of things breaking up and such
I would really appreciate any ideas/sugguestions at all- I'm a little apprehensive to use it at the moment
Thanks so much in advance!
a b U Graphics card
September 3, 2009 9:25:56 PM

The problem is your PSU, in too small for the system...you need a 500W PSU minimun.
September 3, 2009 9:28:56 PM

saint19 said:
The problem is your PSU, in too small for the system...you need a 500W PSU minimun.

Thanks for the quick response.
Is it not safe to run on 405w then?
Do you know how many watts a quad core/ HD/ RAM uses?

Once again thanks for the help
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a b U Graphics card
September 3, 2009 9:36:05 PM

That sounds like a crappy psu, and it is likely the problem. Return it if you can. Replace is with a good brand like Corsair, PCP&C, Seasonic, or Antec. A good quality 400W or greater psu can run your system fine. It's likely the output voltages on your current psu drop a lot under load. That may be why the fans sound like they slow down.
a b U Graphics card
September 3, 2009 9:40:14 PM

For a X4, 2 SATA HDD, a GTX260, 6GB RAM 800MHz, and fans, DVR-RW.....you need minimum a 450W PSU....If you see my system, can be work with a 500W PSU, but the problem is that if you gone make overclok, the PSU isn't support the Watts and reboot the pc, is 'cause i have a 850W PSU

This link can help you with the calculate of the PSU.

http://www.thermaltake.outervision.com/index.jsp
September 3, 2009 9:57:23 PM

Thanks for the help. I will see about returning it and upgrading it. I used the wattage calculator and it came back with about 325W, and thats with the max of the components im not sure about, so that seems ok.
What is the danger?
a b U Graphics card
September 3, 2009 10:03:03 PM

Don't exist danger, the only problem is that if you will do overclock the CPU or GPU or both, the PSU could be not enough and the PC will be reboot.
September 3, 2009 10:15:19 PM

saint19 said:
Don't exist danger, the only problem is that if you will do overclock the CPU or GPU or both, the PSU could be not enough and the PC will be reboot.

Ok thanks :)  It does have voltage and temperature protectors so it should be safe anyway
Plus i'm not planning on overclocking any time soon
Thank you all for the help
a b U Graphics card
September 3, 2009 10:22:16 PM

saint19 said:
Don't exist danger, the only problem is that if you will do overclock the CPU or GPU or both, the PSU could be not enough and the PC will be reboot.

No. :pfff: 

The danger is that, because it is a crappy PSU, it has a high possibility of failing catastrophically. This means things like exploding capacitors or bursting into flames. It's true that you do not need a lot of power, but it should come from a good PSU.

This Corsair is one of the best 400 watt PSU's around and if you hurry, you can get it for $30 after rebate:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
a b U Graphics card
September 3, 2009 10:34:28 PM

Trumple,

Not all PSU's are created equally, you'll be fine with a 400W PSU from OCZ or Corsair, but a 500W PSU from another brand may not be enough.
It all depends on the MAXIMUM COMBINED WATTAGE ALONG THE 12V LINE your PSU can supply, this info should be on a sticker on your PSU.
For your system 360W (or 30 Amperes) on the 12V line should be more than enough, even if you overclock your CPU, but you could probably get by just fine with 300W (or 25 Amperes) if you stick to mild overclocks and limit the system to 1 DVD-drive and 1 harddisk.

The Corsair VX450W has 396W, the Antec Earthwatt 430W has 360W, the Corsair CX400W has 360 and the OCZ Stealthstream 400W has 372W on the 12V line.

People tend to exaggerate the power needs of their systems, I myself am running a core i7 920 (overclocked to 3.2ghz) with an ATI HD 4890 on a Corsair HX520W with no problems whatsoever, so just check the sticker on your PSU and if it has less than 300W on the 12V line(s) just buy one of the PSU's I mentioned and you'll be fine, no need for the expensive 600-800W monsters people on the forums usually recommend.



September 4, 2009 2:29:01 AM

The guy at the shop ripped you off...

1. He gave you a crappy generic power supply

2. It's not strong enough

3. Go back at the shop and ask to be refunded
September 4, 2009 5:02:49 PM

Ok thanks for the help. The upgrade wasnt too long ago so I will see what they say. Otherwise i'l have a spare PSU and have to fork out another wad...
and I dont feel up to re-connecting the power by myself

But thanks again
!