You can't replace the integrated graphics. It is part of the board, not a card. See the manuals for all versions and select your model-

Support for OptiPlex 7010 | Documentation | Dell US

@Mary G is spot on, the Intel graphics are part of the CPU on the MB. And any of the compatible CPUs have very similar graphics. The only way you could get better graphic performance would be with a discrete GPU but which one depends on your system form factor and PSU Wattage. See this forum thread for additional information.

JOcean is correct. If OP has 7010 DT then psu upgrade option is limited. You can still install a low power low profile discrete gpu that beats the igpu of intel 3rd gen cpu in 7010.  Dell supplies oem HD7570 and HD7470 as well as gtx 745 gpu for 7010 DT/SFF that are low profile and low power which do not neee psu upgrade.

optiplex enthusiast brad likes to post tech guide for reference. so here it is

https://i.dell.com/sites/doccontent/business/smb/merchandizing/en/Documents/OptiPlex_7010_Technical_Guidebook_1.pdf

@lkomlos 

XFX Speedster SWFT105 Radeon RX 6400 would be the recommended update.

SWFT105 RX-64XL4SFG2   B09Y7358KJ

Dawid Does Tech Stuff says its the best card in 400 years.

Note the part in his review of the card where he shows you how to change to low profile bracket for smaller units.

https://www.youtube.com/watch?v=EoP9SLHkFY0

By the way, RX 6400 is only 50w, besides having LP bracket, which is why it'll work in a DT.

Hi @redxps630 - public images in Dell Community are downloadable (if you don't know already), so, if you like the following image better...  : )