SLI with no room. Riser Cables?

UPDATED: The situation resolved itself when the controller card started acting flakey. This was probably a result of me trying to jam that second card and the riser cable into the mb at the same time. Eventually, I released the magical blue smoke from one of the leads on the riser cable. The bay still seemed to work, but it seems probable that I damaged it, and the card itself is still fine.


I have an Asus II Rampage Gene (in a 4U rackmount case). It's got a RAID card on the 1x slot, and a "double wide" EVGA 660 GPU on the x16 slot farthest from the CPU.



The RAID controller leaves no room for a second GPU.

Here's what I'm considering, in order of most preferential as I perceive it:

1. Daisey chain two 1x riser cables together and run them up between the GPUs in order to "extract" the controller card from it's current bay.
2. Move one of the GPUs and the RAID controller down a notch with a 16x and 1x riser cable, and hope that I can find an aftermarket SLI bridge long enough to reach.
3. Lose the RAID controller.

Obviously, I could ditch the RAID card and solve this problem, but I'd rather not for a few reasons, not least of which is that solving this sort of problem is half the fun.

I'm assuming that latency is not an issue for either card if I add 12-30cm of cable to the PCI bus, but I could be wrong about that. I'm worried that the extra millisecond introduced by the riser cable on one of the GPUs could turn out to be a problem down the road in an SLI setup.

I assume this isn't an original problem, but I can't seem to put the right words into the Google machine to find a solid answer.

Any help is appreciated in advance.

Why not sell the 680 and buy a faster GPU?

Kinda wanna try SLI only cuz I never have. Alternatively, I could use the ability to hook up more displays.

Sounds like you think there is no hope?

Are these reference blower cards? If so I would think you could use a standard PCIE x1 or x4 riser cable and pass it between the cards given as long as there's enough clearance to plug in the riser with the 1st card installed. If you're down for some modding the 7" on a standard riser should give you enough room to clear the graphics cards. I have seen some new 11" riser cables with molex power adapters floating around lately too and the reviews are pretty good: http://www.amazon.com/dp/B00I4BUUKM

Alternatively I've seen these odd new USB style setups that I personally know nothing about but they supposedly let you run a PCIE device nearly 3ft. from the slot with a pretty minimal clearance. No idea how much performance would be preserved, assuming these work properly:
http://www.amazon.com/dp/B00IKIOXES/

As Atminside mentioned though the elegant solution would definitely be a single GPU upgrade.

I got a 30cm riser cable to see if I could get my RAID controller out from in between my GPUs.

As Galaxy suspected, there is not enough clearance with the riser cable plugged in to seat the 2nd GPU.

I looked into getting a new MB that perhaps had enough room for all 3 cards, but it doesn't make sense to spend that money when for some reason the price has barely come down on the LGA1366 MBs. Even used ones are over $200.

My last hope is to get 1 or 2 16x riser cables...

But there is no way I can run just one card on a riser, is there? The added latency, however minor, with the cable length would probably make the SLI real glitchy, no?

TBH, I'm thinking of getting a second case, riser cables for everything, and moving my disks and cards up into that one.

This wouldn't look as bad as you may be thinking, since I'm using a 4U rackmount case as a HTPC case, and I have an identical one laying around.

What I learned from reading reviews on Amazon, etc. is that riser cables are dangerous. They are not mass-produced. Some 8-year olds may be soldering them in China. Miswired power connections can fry your motherboard or start a fire. Secondly, a lot of positive reviews are fake -- you can see that because supposedly unrelated people reviewed the same totally unrelated things, like a PCIe riser cable and a nose hair trimmer. Thirdly, if you use anything other than an x16 slot, you will need powered risers, because the power specs are different for sub x16 slots (75 vs 25w) Good luck, but I personally decided to stay the heck away from all that.