New graphics card, sudden computer shutoffs.

[iamgregor]

I'm highly suspecting that it's my old 450W PSU that's the problem, but the computer now shuts off every now and then. It's not consitent, and sometimes shuts off after a few minutes and sometimes after a whole day.

Either way, I just got the Sapphire 3850 which says it requires 30amps. I have 2 12v 15amp connectors plugged into it so that should work I suppose, but it could be that the age of the PSU is making it stutter causing the system to shut off to protect itself. To turn it back on, I have to turn off the PSU for a few seconds and turn it back on.

Am I barking up the right tree here? I was looking at possibly getting this PSU to replace it:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817341019

700watt, good brand, low price. Will the power requirements work out ok? Also, my mobo says it needs "ATX power supply (with 4-pin 12V plug)" which I believe is the 20+4 connector on this PSU correct?

Lastly, I believe the Sapphire card uses a PCI-e Power connector (which I have an adaptor for 2x12v 4pin connectors). If I get this new PSU, it would be better to just use the one PCI-e power cord then right?

Sorry for all the questions, but power is probably the thing I know the least about when it comes to computer components.

 

[flyinfinni]

You are probably looking at the right thing. If you have to shut off the PSU and turn it back on to get the PC to turn back on, that sounds pretty much like a PSU issue. What is the PSU you are currently using? I know its 450W but it depends on the rails and quality of power as to whether it can really handle the GPU Requirements.
That OCZ PSU is a solid one, and will definitely run your Sapphire 3850 and will be good for your system. Also- definitely use the PCI-E connectors that are already on the PSU. No reason to use the adapters.
For the Mobo requirements, you have 1 x Main connector (20+4Pin) and 1 x 12V(4+4Pin). The 20+4 is your main mobo connector, and the 4+4 is your CPU connector (which is the required 4 pin 12V plug). It'll powere your board just fine.

 

[delluser1]

The card itself doesn't require 30 amps, that's the reccomendation for the entire system and it's quite a bit higher than it needs to be.
You don't have have 2 12v 15 amp connector's plugged in, the card only needs a single 6 pin power connector and they're rated for 6.25 amps.
The 4 pin 12v cpu plug is seperate from the 20+4 pin main plug.
All of that said, the OCZ is a pretty good deal ( probably much more power than you need ), and yes, you would use one of the pcie power connectors insted of the adapter.

 

[iamgregor]

Awesome and thanks for the quick responses. I'm using Coolmax (pretty decent I think or at least it's served me well so far).

 

[flyinfinni]

Glad to help. Anyway- for a little more info on power supplies, check this out:
http://www.eggxpert.com/forums/thread/323050.aspx

Its a good reference when you are considering PSU's.