Normal psu used externally

[ubisoftblackbox]

is it safe to use an external power supply on a gpu?

i have 2 psu's one 400W but to run the card i need at least 500W . i have another 400w
and i can turn it on by connecting the green pin to the black pin using a wire on the 24 pin connector.
use the 4 pin to pcie 6pin converter and connect it to the graphic card.

the card will draw 75W from the pcie x16 slot and
it will need another 55W.it can draw this much fro the other power supply.

i've done this to run DVD ROMS and Hard drives.

but not graphic cards,should i do it?
or will it do a lot of damage.

 

[1000FPS]

It is quite safe, I've done it before. But I wouldn't recommend doing it for a long term build

 

[ubisoftblackbox]

It is quite safe, I've done it before. But I wouldn't recommend doing it for a long term build

gonna do this to an hd 6850
and is it safe to use the 4 pin 12v rail 1 to power a graphic card
because the 4 pin connector gives more power than the rest of the connectors?

 

[obsidian86]

whats psu's do you have?

 

[ubisoftblackbox]

Best answer selected by ubisoftblackbox.