Hi, just registered here because I didn't quite see the answer and I'm sure someone has probably messed around with this. This isn't really bitcoin specific, but there seems to be an abundance of people here that have played around with pci-e risers, so I figured I might as well ask.
I read numerous times about shorting A1-B17 for getting a slot to register 1x. - https://bitcointalk.org/index.php?topic=36061.0
However, if I have an 8x slot and use a 8x --> 16x adapter/riser, and want it to run at 8x - assuming the board needs to be shorted - I see multiple routes and I'm not sure if someone has actually tested it and has experience.
From the second to last post in the aforementioned thread - https://bitcointalk.org/index.php?topic=36061.msg757661#msg757661
It appears that I could either short A1-B48, or I could short all of the hotplugs (B81, B48, B31, B17) together. The latter option, being either on the female side (16x slot) of the riser, or on the mb slot itself (and only having B48, B31, B17).
The likely conclusion that I think is correct is that shorting B48 on either the female end or the mb end will end up in recognizing the port at strictly 8x, whereas shorting together all the pins simply gives the option of any card running at the highest achievable speed. Can anyone with experience confirm this, or give some insight? Thanks!
As a second part, has anyone had any problems where a board simply would not recognize a card correctly with an adapter? I'm wondering if the riser I had was simply bad as the last pin on female side looks messed up - on one board and in one slot I get it to work fine, whereas the other slot it wont recognize. On another board, it will only work in one slot, and there a quick gpu-z gives me an anomalous result that the card is running PCI-e 2.0 @ 32x and the card errors out. Hoping that a replacement adapter fixes this, but we'll see.