Could I use two psu's to power a motherboard which still sends power to a gpu and one for only the gpu

Question

so I'm having issues with a pc. the pc was already built to work but i've wanted to change the graphics card but the current psu wont be able to handle it alone because its underpowered, the psu is 240watts and its already powering everything else with only 2 cables, originally the 2 cables would transfer the power to everything like the gpu but the new rtx2060 needs a 8 pin connector and wont have enough energy from the current psu since it also has no 8 pin connector, the connectors included are a 6 pin connector which i guess works for the motherboard without 24 pins like others do and there's another 4 pin connector that i guess powers the cpu and thats it. I think its a dell 3668 or 3650 motherboard.

Could one psu thats 240 watts power the mother board and rest while another psu thats 200watts directly goes into the 8 pin connector graphics card, will ther be any problems with this? If only the 8 pin connector is connected?

Answer 1

Recommend pull the existing PSU and replace with one PSU that can adequately supply enough power for all hardware in your computer. I build computers.

Answer 2

It might work, but there are some reasons to expect problems:

• Ground loops: with two different power supplies pushing large currents, points that should be at ground might have significant DC bias across them, or worse, AC or RF leakage.
• Startup: It's unlikely the two supplies would start simultaneously. What happens if either GPU or CPU receives power when the other hasn't?
• Difference in voltage: Some components may be connected across both hot rails of the two supplies. What happens if there's a small difference in voltage between the two supplies? E.G. 4.99 VDC and 5.00 VDC, which may seem insignificant, but across a PC trace with 1 mΩ (milliohm, not megohm), that's 10 A flowing through the trace and the supplies.

Compare the price of a new PS to that of the rest of the PC, which might be destroyed.