Everything is possible, especially in this modding forum... But normally no, you can't power your system with 2 PSU's. Two pins in the large power connector to the motherboard is s used to turn the PSU on/off form your case power button. You can't turn on 2PSU on normal condition. Hacking it would require voiding the warranty of both PSU's. And risk of electric shock as well as permanent damage to your components. Your system with 1 GPU (even with the Geforce 280, and 2-3 HDD's and 2-3 Optical drive and many fans) will/should work with the Corsair HX 620W. Again, it is not the Watts that power-up components but the Amps. So a low end PSU 600W might fail to turn on your computer but a high-end 600W can do the job properly.
Also If i attempt to run the gtx from an underpowered psu, will i risk damaging my system? sorry to be a pain..... cheers
Lamaltor, that guide is excellent. Much like hot wiring a car lol. I'm sure i've done similar things to get round powering up issues with car audio devices. Does it require an ATX psu or will this work with any?
The only reason I asked about the second psu was that it's a bit of a mission replacing psu's, what with all the tucked away cables and everything. However I guess I'll just have to spend a little time on it.
I think i might go for one of these........slightly cheaper than the corsair and seems to have the required amp rating http://www.awd-it.com/scripts/prodview.asp?idproduct=1487 Am I right in thinking this should work?
That is a special PSU. Both PSU have a cable which allows communication between each other, to allow both of them of work properly together.
for PSU to turn on, just short 2 pins in the 24pin motherboard connector. so in that logic, to use 2 PSU, isn't it a mater of hot-wiring both 24pin's 2 "important" pins to the mobo? then they will both turn on and off at the same time. whatelse is there required for 2 PSU to work together?
Actually no. Based on the articles that was posted above. The PSU that doesn't have the motherboard connector onto the motherboard would always stay ON unless you switch the PSU OFF from the back switch, and not shutdown by the OS or system power button (computer case button). Giving power to components like GPU while the motherboard turned off is not something that was designed... and could potentially damage the video card. It's fine for optical drive and such... but these devices don't use much power compared to a video card. Also it's going to be a pain to turn ON/OFF your computer with proper order and always go on the back of the comp and such. Also, another problem that could arise is what happens when the reset button is pressed. I say not worth the trouble unless you have money to throw away... but then you get a 6000W PSU or something ridiculous like that and you are set.
that's what i was trying to say! both PSU have their "on-off" pins connect to the motherboard, thus will power on, or power down according to the motherboard.
I've been considering getting the Enermax Pro 82+ 625W ATX12V to power my GTX 260 card and the rest of th system. This should do the job shouldn't it?