Hello I have this XPS720H2C with 2 GTX8800 and I want to change the video cards with new ones. So I have purchased two brand new GTX 295 and I installed them. But Surprise! the system won't boot. After reading the GPU install instructions it appears that the problem is the lack of a 8pin power connector in my system. Those XPS 720 H2C do not have a power supply with general power conectors to fit any power cable adapter they only have four 6 pin connector coming from the Power Supply straight to the video card. So my questions are: Do I need to change the Power Supply? Is there a 6 pin to 8 pin cable adaptor? And if I buy a new Power Supply with 8 pin connectors, do I need a special one for BTX format or any ATX one will do? (Dell XPS720 is built on a BTX case) If you can help with some advice it would be nice I am sitting next to those 2 GTX 295 it's pretty frustrating.
look in the box you got your 295 in there sould be a 8pin connecter with to molex conecters at the end. plug that in to your 295 with 2 molex conectors. and that should solve your problem
Yeah I have those in the gpu box but I only have only one free molex coming from Power supply and I need 4 of them, 2 for each card. Anyway there is such a thing as 6 pin to 6+2 pin adapter those should fix my problem.
2nd PSU probably won't fit - you'll probably need a beefier PSU OP, Dell don't give over-specced hardware unless they really have to. Even if you could plug them in I suspect you won't have the power to make that setup run properly. Tbh you'll likely find one 295 will be plenty of horsepower, and you probably won't need a PSU upgrade to get it going.
i recon you should try and send back the 295's and get your money baack and spend it on something else in your rig because two 8800gtx is quite a lot of horse power and you could quite easily wait to see if fermi is any good
This should sort out the connection problem BUT before you do use them make sure that your PSU is up to the job. Check the 12v rating of your psu, should be either on the side of the PSU or in the manuals from Dell. I would expect you will need at least 700W on your 12V rails. If your PSU is struggling you may wish to have a look at something like this.
I found some 6 pin to 8 pin adapters and the GPU's are up and running now. However my 1000 watts PSU is indeed at the limit. IF I use two displays it is still ok but if I turn on the quad SLI on one of them while keeping the other one on, my PC just turns off. Anyway I am ok with it as I either use 2 displays without SLI or just one display with SLI. Thank you for the tips.
well after more testing it seems my PSU is not really enough for this setup so now I need to upgrade my PSU. The thing is I have a BTX case. Can I fit a AT PSU on this BT chassis DELL tower?
