750w is fine. Max I have pulled is
550w at the wall when I OCed the card a bit (FE 3080, 3700x, AIO, Fans, SSD, 1xHDD). What is probably more relevant is the quality of the supply to the two 8pin gpu power sockets.
If you have a hungry CPU and one of the OC cards and Overclock things then yea you will need a beefy PSU.
On the other hand if you undervolt then you get a lot less power, heat and noise for little (if any) performance loss. This could be a way to live with a lower PSU until you upgrade.
I just ran the superposition benchmark and took some readings with a meter on the wall socket and HWinfo64 for the max GPU power.
- Stock Wall:473w GPU:318w
- OC Wall:525w GPU:362w
- UV Wall:360w GPU:222w
The OC was all the power and voltage sliders up, +50 core clock and +500memory.
The undervolt is 806/1800 with +500mem clock. This is what I normally run now.
Oh and I have an Corsair RMx 850 so plenty of headroom for my setup.