william p :
Zotac makes a GTX1050Ti Mini which is a single slot card that will fit your BTX without mofification. Also a Zotac GTX1050 Mini.
Q9650 is max. CPU but Q9550 is popular also.
Dell T9303 heatsink is an upgrade also.
DirectX12 is backwards compatible.
meanness6 :
I looked at the Evga 1050ti on newegg and I see 5 . The problem I am stupid about to tis the one I need . I understand the GB part but nothing else. Thanks
Ah, no problem. From looking at the manual for the mini tower optiplex 780, it looks like a dual slot card will fit, so your major concern will be length of the card. So first measure the spot to see how long a card can be. If you can fit one with dual fans that is better for keeping it cool and will be more silent. The price differences between the EVGA models is from cooling and speed of the overclock. The differences in fps probably isn't that much but if you want the faster cards that's up to you.