Hey guys, this is the first guide I ever wrote back in 2008 when I was just starting out in the community. I originally published this guide on overclock.net, but decided to put it back on here as well.
So. I have an 8800GTS 320MB sitting around. I want to use it, but how do I place it into a Rig that has only a 300W power supply without blowing the thing up? How do I do this without spending money?
The answer is mod yourself a GPU dedicated PSU.
Heres what I did.
I have an old dell that sits around and collects dust. So I decided to part it out for fun. I realized that I had a perfectly good 250W power supply. Now, I know power supplies have been modded before to work without mobos, but this one wasn’t any normal ATX PSU. So I started to research the pinout on the particular power supply. I stumbled across this:
This is the exact pinout for my power supply. I discovered the Grey wire is the switch for the PSU. I need to connect this to ground, in order to get the PSU running without a motherboard. Then I could connect it to a molex to 6-pin PCI-E connector in order to supply enough power to the 8800GTS.
So I started by removing the PSU from the old dell machine:
I compared the pins on the motherboard connector the the pinout shown on the website. They matched. The next part took me awhile. I needed to find a viable solution to connecting the PSON (gray) wire to ground (black). I did not have any copper wire, so i used a very thin piece of solder wire.
I bent the solder into a U shape, and fit it into the 2 pin connectors. It fit perfectly. (sorry for the blurry pic)
Now to test it. I plugged the power supply into a wall socket, and tadaa. The fan was spinning, and that indicated to me that the power supply was active.
I decided to finally connect it to the 8800GTS 320. I used a Molex to 6-PIN PCIE adapter cable to do this. This is shown here.
I started up the computer with the 8800 inserted, and the PSU mod in place feeding power to the card.
It worked perfectly with no issues or warnings. YES!
Heres one last final pic of the entire mod put together. (I warn you, it’s very messy, Ill organize it later):
So after I found out it worked, I installed 177.40 drivers and got folding. I now have 2 dedicated GPU folding rigs.
There has been no problems whatsoever when the 8800 takes on load in the modded computer. Success!
I hope this will help some people who aren’t willing to shell out for a new power supply. And this mod was fun to do!
WARNING: If you perform this mod I nor overclock.net take any responsibility for any PSU failures, hardware failures or other problems!
***Also, If you perform this mod the life of the modded PSU may be severely shortened if you don’t load the other rails of the PSU. This can be done by also connecting it to optical drives or other non-critical hardware. Thanks to those who gave me the heads up on this!
**** And remember, if you perform this mod and turn off the computer it is used in, remember to remove the plug from the back of the modded PSU, or it will stay on without a load. Doing so may result in the life of the psu being severely reduced!