Hello i want to run a graphics card in an old oem computer that doesnt have a 6 pin connector. Can i use the 6 pin connector from another computer thats sitting right next to it and have both computers running at the same time?
So that older computer will be using its stock psu for all components except the 6pin which it will be getting power from an adjacent computer that will be running
I've done pretty much the same exact thing, only different ;-), with an old "office" computer. It's not the prettiest answer, but it does work. Only I didn't leave the old psu in a functional pc. I set it behind my old office pc and jumped the mobo connector so that the psu would power on. Hell in my Power Edge 2950 I run as a Home lab server, I used an old psu from one of HP's office (read, weak ass pc) computers. Was under 300 watts, so the RX580 8GB card works fine.
Do you really need the 2nd old pc to continue running while sapping off some of its 12volts? Or is it just easier for you to use that 12volts without taking out the psu?
It's best to switch on the aux psu first, then your game rig.
Mine was also in a "bookself" type case. The small form factor business machines from 10 to 15 years ago can make excellent gaming rigs with minimal effort and money invested.
Several "answers" to your inquiry are obviously not based on true knowlege, but feelings. Try not to repair or mod hardware based on feelings brother. Dig a little and find that knowledge.