2 psu's 1 for the system 1 for the gpu

ok...i just bought a new computer.....and i used my old graphics card.....7800 gtx...it is pci-e...there is a power plug in that is supposed to be in the power supply...the card asks for atleast a 400 watt powersupply but the new comp...only came with a 300...my question is if i can take the old power supply....a 350....and run that one only from teh graphics card...other wise that my adapter and plug it into the graphics card....one reason i dont know if it is safe is if it is grounded correctly.....it my sound stupid but i dont want to buy another...And question 2 is if i do have to buy another psu....are they all the same size?....

sorry if it is confusing....it was the best way to put it

 

Well, if your new machine is a generic model, the P/S should be a standard size. You do NOT want to try to use two power supplies, buy one 500W (or better) supply, and make sure you don't buy one of hte $20 models.

 

Kevy214, you posed an interesting question.

Although this article is a little over a year old, with the power hungry cards being produced today, in the future we may very well see the need for dual power supply's.

http://www.anandtech.com/tradeshows/showdoc.aspx?i=2770

 

Synchronizing two supplies properly would be a nightmare unless they were designed for the task. I think we're a ways from needing dual supplies.

 

JW, you may be correct, however when ATX version 2.2 was adopted in 2003/2004 all it provided for was the 24 pin mainboard connector to support PCI-e.

Now we're using the extra power on the PCI-e buss, plus 1 or 2 additional connectors. Where it will all end, who knows.

 

Lol, things changed while I was thinking about them. Check these out.

http://www.thermaltake.com/product/Power/PurePower/w0099/w0099.asp

http://www.thermaltake.com/product/Power/PurePower/w0130/w0130.asp

 

I see they've tapped off the main supply for sensing when to power this one. It's really a different way to package more power.

One issue here is the lack of proper cooling. You'd be either pushing hot air out the front of the case (probably not all that desirable), or putting it into the case (definitely not that desirable!). I'm not all that impressed. I'd much rather have a proper single P/S.