That is a helpful YouTube video. I am aware of this psu but have not seen a good demo. if your current psu is doing well for you, there is no need to upgrade it yet unless you want to change to a more powerful gpu. the Q9650 cpu will work for 780, regardless of psu power rating. gt1030 is connected to the rest of the system using a PCI-Express 3.0 x4 interface, your 780 has q45 chipset using PCI Express* x16 Gen 2.0.  gt1030 is backward compatible and running at gen 2.0 speed and using x4 lanes, thus 2.0x4.  Although the x16 slot can support up to 16 lanes, your card only takes 4 lanes.
Hello Dell Community, I hope all is clear for you on this hard times... Few months ago, i updated a old Optiplex 780 with a SSD, a new grphic card, 8gb of ram and a sound card. This OP work great and i can play some game, watching HQ videos and more. I would like to thanks all the poeple than can help me for choose a correct combination of this new parts! On web search i find a brand new 280W power supply and appear to be able and compatible with the 780SFF Somebody have hear about that? The power supply is from the Optiplex XE, there's a video: [URL]   Now i would like to know if i can put a Q9400 - Q9550 - Q9650 with this new PSU and if i dont have too much bootleneck with my actually graphic card EVGA GT1030 SC ? This new CPU would be appreciate for multi task and more    Thanks in advance for your help and take care! P.S.: you can see my all configuration on the signature and if you need more infos please ask me! 
Optiplex 780 SFF