PCIe kludging

[x88x]

I'd seen guesses/etc at this elsewhere, but this is the first time that I've seen it actually done and working. Apparently it is possible to block off PCIe lanes on a GPU card and it still work. (http://hackaday.com/2011/01/02/hackaday-links-january-2-2011/) So, from that, I'm guessing that the bus uses the first lane for all the really important communication, detects how many more lanes it can see, and uses all that are available. Now that I think about it, that explains why an x16 card works just fine in an x8 slot.

So, lesson of the day is:
Next time you need to add another GPU to a PC and all it has is a PCIe x1 (or x4, presumably) slot, don't waste money on those weirdly expensive x1 GPUs. :D

[Diamon]

As far as I know there's no performance increase in running a GFX card on 16x rather then 8x lanes. But you'll definitely lose performance if you run a high-end GFX card on 1x lane.

[NightrainSrt4]

I did this last year when I wanted to use three monitors on my rig for SoftTH.

The difference being I physically cut the connectors off my 7600GS pci-e x16 to x1. Worked perfectly. I had to physically cut the entire extra set of connectors as they were hitting the board when I tried only cutting a notch. I'd rather chop up an old card that wasn't getting used than cut up my motherboard. With the chips on the board I would have had to cut the card anyway. Works great. The pictures of the 3 screens that were in my FS thread, the Samsung on the left is running off the x1 7600.

I might be able to grab a pic if I can be bothered to dig it out of the storage bin.

[x88x]

As far as I know there's no performance increase in running a GFX card on 16x rather then 8x lanes. But you'll definitely lose performance if you run a high-end GFX card on 1x lane.

There's another thread about this somewhere around here, but iirc the consensus was that no, most don't benefit much from more than 8 PCIe v2 lanes, unless they're pushing heavy stuff at a lot of pixels.

[Technochicken]

I did this with my old 8500 gt:

http://www.techspot.com/gallery/data/501/medium/DSCN1305.JPG

It works perfectly well. I did it by scoring the board with a box cutter and then just snapping the extra pins off with pliers.

[dr.walrus]

It's much easier to cut the plastic on the motherboard at the back of the slot, surely?

[Technochicken]

I'm not sure, but would rather mess up on a low end video card I don't need than a motherboard I do. I have seen some pictures from when some guy removed the plastic on the motherboard, and he could not cut it. He had to melt it away with a soldering iron.

[nevermind1534]

I'm not sure, but would rather mess up on a low end video card I don't need than a motherboard I do. I have seen some pictures from when some guy removed the plastic on the motherboard, and he could not cut it. He had to melt it away with a soldering iron.

A Dremel would be able to, but I'd be worried about it damaging the pins on the slot.

[dr.walrus]

sharp knife, just cut the thin part at the back of the socket away, 20 seconds