My friend picked up a HP Z800 Workstation and wants to make it a budget PC. The specs HP Z800 workstation. Intel Xeon x5680 @ 3.33 Ghz, 6 core, 12gb ram Nvidia quadro fx3500 MOBO Hewlett-Packard 0AECh
He's looking to play FPS and racing games in 1080. Is looking for the most bang for his buck. I'm thinking a used GTX770 might be a good choice to give the graphics a boost but not sure if it will work on this MOBO.
From what I'm seeing online, the power supply that is installed in the Z800 workstation only has one 6 pin pcie power for the gpu dedicated, so whatever you buy has to be a single 6 pin power maximum. That is going to limit you severely unless your friend is willing to spend maybe $150 for the new RX 460 or RX 470 when those come out, as they look fairly capable in terms of specs and will consume little power which would make it ideal for this use case and system.
I think I might have that current workstation at the office. It is a six core that is just like the intel i7 970 Socket LGA1366, right? That thing turbos to 3.6 if it has a good cooler. Mine has a 450 W PSU, and I tested my old GTX-660ti when some jerk on ebay returned it claiming that it did not work (it did and they next guy loved it). The motherboard is huge, blue and has lots of slots.
The motherboard will take any GPU, but the problem is power. I would recommend a a GTX-750ti. It will run that fine, or perhaps a GTX-950. If you can get your hands on a GTX-1060, then that might work great as well if the power draw is not excessive. I could be wrong on that though and perhaps you require a GTX-950 or 750. Do remember to pull the Nvidea graphics adapter out so it does not waste power.
Your GTX-770 will require a PSU upgrade. Also, you need to get some kind of audio solution, either USB headphones or a sound card. My z800 has a legacy PCI slot, so you can get a cool old sound card like an HT Omega Claro or an Auzentech on Ebay, or get an Asus at Microcenter or NewEgg. I am serious about the audio. I have this thing at work, and I still had to put a sound card in it.