Hacking a motherboard for more PCIe x1?

[Flashman]

Hey smart folks,

I've got a mishmash of marginal GPUs getting retired from main mining machines, which are gonna be litecoin dedicated now I guess. However, the prospect of unused hash lying around irks me a bit, but of course, spending any kind of coin to get it running is not worth it. Just wanna glom them all together in one machine that I can turn on for new alts or leave pointed at middlecoin overnight when the electric is cheap or something.

So, I'm wondering about hacking a plain jane motherboard to provide more PCIe x1 connections. I've got a board I don't particularly care about, has one PCIe x16 and one PCIe x1 on it. Chipset is Xpress 200 for intel, board is an intel D101GCC. Chipset is supposed to have 22 lanes, but figure I'm going to have an easier time stealing lanes off the x16 and crippling it to 8 rather than finding the undeployed ones off the northbridge.

I've got some x1-x1 extensions I got cheap, figure I might hack up one or two of those. Don't wanna hack too many up trying though.

Has anyone done anything like this? Are there any resources anyone can think of to help me out? Been searching here a bit either there's nothing or I'm not getting lucky with keywords.

Thanks for any hints/moral support/allegations of idiocy for thinking about it.

Flash

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[PEBKAC]

It seems this would be quite possible, based on a quick Google search.

There actually are PCI to PCIe x1 adapters you could use to transform regular PCI slots into PCIe.
http://www.amfeltec.com/products/pci-to-pci-express-adapter.php

Another option would be a PCIe Splitter. The particular example I found splits a single PCIe x4 slot into four PCIe x1 slots.
http://www.amfeltec.com/products/x4pcie-splitter4.php

[Flashman]

Thanks,

I see from other posts mentioning those though that they appear to be prohibitively expensive. Can't believe there's not a way to figure it out in a more "passive" fashion, doesn't look like motherboards with more than a couple of slots need all that junk to support them. I guess it might be industrialized with buffers and extra power regulation.

I'm coming up with some intel that PCIe cards short certain pins to tell the bus how many lanes they use. I'm guessing I'd have to jumper the x16 slot to x8, anyone know of a good writeup on how that works?

[Flashman]

Hokay, got the presence pin thing sorted in my head.

Been reading about the physical layer a bunch of times, and nowhere do I see anything like a mention of address decoding required, but the simplest risers I'm finding pictures of, do seem to have some logic on...
http://www.compsource.com/ttechnote.asp?part_no=RSCR2UT2E8R&vid=428&src=F
http://www.wiredzone.com/Supermicro-RSC-R2UE-2E4R-2U-PCI-E-%28X8%29-TO-2X-PCI-E-%28X4%29~10017841~0.htm

Was hoping to nibble at the edges of the technical stuff an pull out what I wanted, but possibly time to suit up and dive in to the full spec.

[Flashman]

Most interesting article I've bumped into so far...
http://diymediahome.org/dual-tuner-mini-itx-build/

Seems those mini-ITX/HTPC guys are interested in slot splitting.

[Flashman]

Got no further, found another article that has a couple of useful hints in...
http://blog.zorinaq.com/?e=42

It's kinda depressing that this thread propagated to google so quick and is appearing front page on most of my searches LOL

[PEBKAC]

Got no further, found another article that has a couple of useful hints in...
http://blog.zorinaq.com/?e=42

It's kinda depressing that this thread propagated to google so quick and is appearing front page on most of my searches LOL

You do understand that this forum, as many others, is very likely to have Google tracking code installed? (primarily for Analytics)
Because Google also uses that to find out what is interesting to you and customises their search results to be as interesting to you as possible.
Thats why this page is quite likely to turn up first or on the first page of your searches, but not for me.