The first graphics cards that support OpenGL 4.5 with bindless textures and everything are the Geforce GTX 600 series and the Radeon HD 7000 series. All later AMD/Nvidia cards do as well. for a cheap low power gpu that works with 790DT you can consider entry level geforce 600 series such as gt 630 or gt 620.  It needs to be low profile short bracket to fit DT case.  GT 630 / 620 supports OpenGL 4.6 [URL] [URL]  
i was currently using a dell optiplex 790 i5 DT, mainly using it to play minecraft and there were no issues.however to play the new update game you require a minimum of openGL 4.4 but the intel HD graphics 2000 can only run up to openGL 3.1,can someone recommend me a gpu compatible with the dell optiplex 790 i5 DT that does openGL 4.4, nothing else is really needed as i wouldn't put it to use so a lower end gpu is best ? side note if this matters ? nothing has been upgraded before so the specs are the default.thanks in advance !
dell optiplex 790 i5 DT gpu upgrade