dell optiplex 990 DT Mini Tower PSU

[paullewisville]

I'd like to upgrade my Dell 990 PSU so I can use a video card. The standard PSU is 300 watts.
The system configuration is:
16 gig ram
I7-2600
80 gig internal HD
1000 gig external HD
BIOS: Dell Inc. A06 07/25 /2011
Windows 10 (upgraded from 7)
My questions are:
Will a large PSU 600-700 watts fry my motherboard?
Should I upgrade my BIOS first?
Do I choose my PSU based on the video ram or gpu?
Thanks

 

[william p]

That should take any standard ATX PSU. Check the reviews (by testers not owners) and the PSU Hierachy or Tier charts. Buy quality. Seasonic EVGa, Corsair are respected brands. You should be able to run up to a GTX1050Ti 4GB w/o a PSU swap.