Question Need suggestions for graphics card upgrade

[Krakboi]

I currently have a Dell Optiplex 9010 i7 @ 3.44ghz with 20GB Ram and 1.5TB HDD.
I recently installed a BenQ monitor that should output 1080p resolution but the graphics card I have right now ( Intel HD Graphics 4000)is not doing the job.
I would like suggestions on a superior graphics card I can install that won't warrant having to get a new PSU.
Thanks in advance.

 

[SkyNetRising]

What form factor Optiplex 9010 ?
What model PSU does your pc have?
What's the purpose for discrete graphics? What exactly integrated graphics can't do for you?
What is your budget for graphics upgrade? How much are you willing to spend?