Yes you would need to upgrade psu to 350+ w.  790 MT stock psu is 265W.   basic psu calculator: Load Wattage:288 WRecommended PSU Wattage:338 W even if you use only ssd and no dvd, Load Wattage:246 WRecommended PSU Wattage:296 W the gigabyte low profile 1050ti in video will work as long as psu is upgraded.
So I have a gigabyte GTX 1050ti 4GB ddr5 low profile and I'm wondering if it'll be compatible? (this one) Will I need to upgrade PSU or will it at all work? Edit: I have 16 GB of ram and an i5 2400
Dell Optiplex 790 minitower GPU question