I'm a newbie too but my 2 cents based on what I've learned so far.

You're much better off going with the 1200 watt PSU. If I were you, actually, I'd get 2 PSUs for 750W each and chain them together using an Add2PSU. Don't risk overloading your PSU or it could burn out, your GPU could burn out, both could burn out, or worse. I had it happen to me but luckily I caught it before any major damage was done. I use 3 PSUs (750W chained) now for my 5 GPUs. Overkill? Sure. But I have peace of mind

Hi everyone,

I have an MSI Z77a-GD65 and I need to short one of the slots to get it to work. The MB was working fine with 5 GPUs until a couple of weeks ago when one of the slots stopped working. I know it's the slot because when I plug this GPU and riser into another slot it works and when I plug another GPU and riser into this slot it doesn't work.

So, I see posts about presence shorting a 1x slot. I found a page here that provides description of pins for all slots (1x, 4x, 8x, 16x).
http://pinouts.ru/Slots/pci_express_pinout.shtml

All slots except the 16x seems easy enough but the 16x has multiple presence detect, hot plug detect, hot plug present detect, etc pins. Any idea how to do a presence short?

I'm using a 1x to 16x powered riser.

Help will be truly appreciated.