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Topic: PCIe x1 -> x16 extender workaround for some mobo's (Read 4495 times)

legendary
Activity: 2450
Merit: 1002
Well, I blew up the mobo I was mining on. Guess its x1 slot couldnt handle the power w/o molex injection. It was an old S939 board had laying around. So, gonna buy new mobo / cpu & RAM today probably.
Heres a question. The mobo Im thinkin bout buying is MSI 890FXA-GD65, has 4 PCIe x1 and 2 PCIe x16

It also has a 6pin PCIe power connector on board for the PCIe slots. Do you guys think this would sufficiently power all the PCIe slots, so I wouldnt have to use molex injected extenders?
hero member
Activity: 575
Merit: 500
Had to do this for 3 slots (16x_1 16_2 8x) on both my GA-990FXA-UD5 for them to take 1x extenders in those slots when running 6 cards, so it applies to some newer boards as well.
member
Activity: 93
Merit: 10
So far, none of the motherboards I've tried needed any tweaks to the motherboard. I saw that thread once, and I majority of the time it applies to older motherboards. Which motherboard are you using?
hero member
Activity: 697
Merit: 500
There is a thread somewhere around here with a list of boards that require the presence pins to be shorted.
vip
Activity: 756
Merit: 503
Thank's might be usefull when I receive my extenders.
legendary
Activity: 2450
Merit: 1002
I dont know if this is a known trick or not. But, last night I hooked up my first GPU using extender cable and for the life of me couldnt get it to work in any combination of GPU's, slots .. on my motherboard.

Turns out after further research I discovered some boards require the presence sense pins to be properly shorted by whatever device is plugged into it.
So, I discovered a trick using a wire to short the needed pins in the x1 connector on mobo, it overrides the sense function and will run w/e device is plugged into the slot regardless.
Heres the graphic:
http://blog.zorinaq.com/images/pcie-short-schematic.png
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