Insufficient proprietary power supply

NoobUserLOL

Commendable
Dec 29, 2016
13
0
1,520
this is the first time ive posted in the forums so bear with me plz.

not long ago i had bought a HP Z200 workstation, and several months later a GPU (gigabyte gtx 650 oc 1gb) which requires a 400 watt power supply to work efficiently.

the stock power supply which came with the case was exactly 320 W but the GPU somehow automagically underclocked itself and is still working perfectly despite the deficient power however im not getting the performance the GPU should be delivering and that explained a lot.

Ive already realized that no ATX power supply can work with the proprietary HP motherboard (20 pin) in my case

To counter this problem ive determined 2 solutions:

1. Buy another power supply and connect it just to the GPU and let it dangle outside the case making it look like that a moron has set up this low tier PC

2. Use another Proprietary PSU (450W) from an older HP case the hp xw4600 workstation. however im not sure this methord will work as it was a seperate PSU designed for a different proprietary motherboard , furthermore i think that the mobo has a 24 pin slot (still unsure) and that just reduces the chances of it working properly.

Most ATX power supplies (including my cousins, with which i have already meddled with) dont even FIT in the Z200 case as they are too small.

I plan on changing the case and the motherboard once i have enough budget but for now i need a crude solution.
 
yup i found this solution in other forums but the problem is that amazon and ebay (which are out of stock too) dont make deliveries in the country i live and newegg is always out of stock, ive learned that its unlikely for other cases' PSUs to work with another case and mobo.

so that seriously forces me to go with step 1, so which power supply should i use to power the gpu alone? i currently have access to branded 350W and a 500W PSU which one should i use? how much power will the graphic card i mentioned drain at most from both the external PSU and the PCI-E slot on the mobo ?
 
for the 500w one:
Cooler Master Extreme Power Plus - 500W

as for the other:
Corsair VS Series VS350 - 350 Watt

almost forgot to mention that both of them are old and used (not excessively tho) for 2 years each, both sitting in the attic of some relative... waiting