optiplex 790 DT, graphics card help

https://www.amazon.com/GIGABYTE-GeForce-GV-N1030D5-2GL-Computer-Graphics/dp/B071DY2VJR

Processor is too weak for this graphic card:

Intel Core i3-2120 (Clock speed at 100%) with NVIDIA GeForce GTX 1050 Ti (Clock speed at 100%) x1 will produce 27.43% of bottleneck. Everything over 10% is considered as bottleneck.

Graphic card and processor will work great together:

Intel Core i3-2120 (Clock speed at 100%) with NVIDIA GeForce GTX 750 Ti (Clock speed at 100%) x1 will produce only 0.02% of bottleneck.  At least 8GB RAM is recommended.

The above quotes are from PC Builds.  Of course, make sure you get the LP GDDR5 version

YouTube videos have been showing 60w GTX 750 ti and 75w GTX 1050 ti cards being run on stock PSU's in Optiplex's including DT and SFF models.  Since it was harder to pull up the 790, I pulled up the similar 7010.  https://www.google.com/search?client=ms-android-americamovil-us-revc&ei=1-viXtGhHLSTwbkPk_-ckAU&q=optiplex+7010+gtx+750+ti+youtube&oq=optiplex+7010+gtx+750+ti+youtube&gs_lcp=ChNtb2JpbGUtZ3dzLXdpei1zZXJwEAMyBQgAEM0COgQIABBHOgYIABAWEB46BQghEKABOgUIIRCrAjoHCCEQChCgAVC0Glj8QWD1R2gAcAF4AIABxQSIAbMLkgEHMC43LjUtMZgBAKABAQ&sclient=mobile-gws-wiz-serp 

While the 790 MT has 265w PSU and 7010 275w, DT's in both are 250w.

From PC Builds:

Graphic card is too weak for this processor:

Intel Core i3-2130 (Clock speed at 100%) with NVIDIA GeForce GT 1030 (Clock speed at 100%) x1 will produce 70.74% of bottleneck. Everything over 10% is considered as bottleneck.

For NVIDIA GeForce GTX 750 Ti can i get away with 4gb RAM will it still be good?

Intel Core i3-2120 will need at least 8GB of RAM to work well. If you are planning to work with some memory intense programs, or run multiple programs at ones, you should consider adding even more memory. - PC Builds  This is what comes up in PC Builds when pairing the I3-2120 with the GTX 750 ti.

So if you try it on 4GB, I'm not sure what effect it'll have - if you don't get the expected FPS or resolution.  You could still try it, it won't break anything, and post the results here.

I posed the question in Google, "What effect does RAM have on GPU card?"

https://forums.tomshardware.com/threads/will-my-cpu-and-ram-affect-the-performance-of-my-graphics-card.1944671/ - I could not explain it any better.  Another way to explain it is you're familiar with how bottleneck works, right?  Whichever is weaker, the CPU or GPU, becomes the skinny little bottleneck, or the throttler.  But picture this without bottleneck - more RAM = bigger bottle for all of that data.

Top answer in Google is good to know too:  Adding more RAM will improve your system performance since it'll have more breathing space, but it won't increase graphics memory. No it won't. The graphics card has memory that is only used on the graphics card itself.

You can Google it yourself if you want.  No shortage of reading material.