I have Fsp hydrp G 750w and 850w PSUs. Does watt difference matter If I connect 2 of them to one rig? Will they work properly? What do you think?
No, it doesn't matter. As long as you are not crossing power feeds, you can use two PSUs. Use the 750W one to power the Mobo and maybe 1 or two cards and their risers. Then use the 850W one to power the rest of the GPUs and their risers. The GPU and riser have to be powered from the same PSU. Never ever ever power a GPU from one PSU, and the riser from another PSU. There will be lots of smoke.