Looking for a very "low profile" SLI bridge connector...

Silenus

Senior member
Mar 11, 2008
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Does anyone know of any SLI bridge cables that have a very low profile height? What I mean is that pretty much all SLI connectors stick up above the height of the card a fair amount. I am looking for one that rises above the height of the video card as little as possible. Trying to do a setup in a 3U rack mount case which has very little clearance above the cards. Too little for the standard SLI bridge. I need a very "thin" sli connector otherwise it will have to be limited to a single card....which is sad. :(
 

nenforcer

Golden Member
Aug 26, 2008
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The dual SLI connectors I have seen are the flexi material which pretty much are parallel when fastened to the cards. In addition you can move them or have other cards inbetween the SLI'd video cards.

Its the triple SLI connectors which have the rigid PCB connector I could see causing a problem. These have no give at all but any card which support 3x SLI are dual slot so there would be no room anyways.

Do you not have a dual flexi SLI bridge?
 

Silenus

Senior member
Mar 11, 2008
358
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I have the flexi bridge. The cable itself is not a problem. It's the plastic connector which physically connectos to the card. It sticks up above the height of the top edge of the card enough that it will not allow the cover of the case to go on. Pics I took below which illustrate the issue. This is why I'm looking for something "lower" in profile...though I very much doubt anything exists. This is a very niche problem.

PS- Please ignore the slot location of the video card in these photos. Pics shot with a non SLI motherboard so the card is not in the "correct" slot. This is just to illustrate the height issue of the SLI bridge.

SLIBridge1.jpg


SLIBridge2.jpg


SLIBridge3.jpg
 
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Ruger22C

Golden Member
Sep 22, 2006
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I'm just guessing, but I bet the only options you have are:
Leave the side off of the case.
Get a new case.
Get new video cards.

Make your own cable.
 

Silenus

Senior member
Mar 11, 2008
358
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I'm just guessing, but I bet the only options you have are:
Leave the side off of the case.
Get a new case.
Get new video cards.

Make your own cable.

I've considered all these already. This is actually a project at work for a customer, not for myself. Side off the case is no good as these are going to an end user in a rack and would be 4 of these 3U's stacked on top of each other, each with the same video setup. So even without the cover the connector might hit the bottom of the case above it...not to mention it won't look right for a paying customer.

New (4U) case I threw out there but customer won't go for it. they actually wanted to go down to a smaller case but the 3U is the smallest we can do with a "serious" video card. 3U is the max they can fit in their rack setup.

New video cards is maybe a possibility. They really need as much video power as possible. Previously this system was tested with a single Radeon 5850...it works but their application may run better on nVidia so we are trying the 460. 460 is is most powerful nVidia card that will fit this case...everything above has the PCIe power connectors on the TOP edge of the card....which also will also interfere with the case cover. The idea was to test an SLI config and see if that could squeeze more GPU power into this small case. There are some non reference 5870's that will fit also...but again the customer really wants to try an nVidia card as of now.

Custom SLI cable. That would be nice. However....this will be for production machines that we would be building regularly. So if a custom cable could be made...it would be something that we need again on a regular basis. Anyone know any place that might be able to build custom SLI cables at reasonable cost??
 

Ruger22C

Golden Member
Sep 22, 2006
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"Custom SLI cable. That would be nice. However....this will be for production machines that we would be building regularly. So if a custom cable could be made...it would be something that we need again on a regular basis. Anyone know any place that might be able to build custom SLI cables at reasonable cost?? "

You sure you can't just take the cable you have now and shorten the plastic? It should still look professional. . . file it down
 

Silenus

Senior member
Mar 11, 2008
358
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"Custom SLI cable. That would be nice. However....this will be for production machines that we would be building regularly. So if a custom cable could be made...it would be something that we need again on a regular basis. Anyone know any place that might be able to build custom SLI cables at reasonable cost?? "

You sure you can't just take the cable you have now and shorten the plastic? It should still look professional. . . file it down

The top of the gold finger on the video PCB bottoms out inside the SLI bridge connector...so shorthening the connector won't help it seat further down.

It sucks how close is it is to fitting. I need literally 1/8" of an inch to clear everything, even 3/32" might just do it. So close yet so far... :)
 

Ruger22C

Golden Member
Sep 22, 2006
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The top of the gold finger on the video PCB bottoms out inside the SLI bridge connector...so shorthening the connector won't help it seat further down.

It sucks how close is it is to fitting. I need literally 1/8" of an inch to clear everything, even 3/32" might just do it. So close yet so far... :)

If it bottoms out.. you should have spare room.
Shorten the finger. What do you have to lose? He's not going to SLI it if you don't.
 

Silenus

Senior member
Mar 11, 2008
358
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By the way I have tried grinding down the plastic nubs and the metal pins onthe top side of the sli bridge. It got me closer but I am still like 1/16" too high!

SLIBridge4.jpg

SLIBridge5.jpg



If it bottoms out.. you should have spare room.
Shorten the finger. What do you have to lose? He's not going to SLI it if you don't.


Yes shortening the finger might in fact do it. However...these would be regularly ordered system from us so it would have to be done every time. We will also inevitably have a card go bad or otherwise need repalcement. Will eVGA warranty the card if we have ground down the gold finger?! Hard to think they would be ok with it!

In reality my last resort may in fact be to have a new bottom plate made for this case (this is our own design), which will lower the motherboard and thus the cards just a little. Combined with a new rear panel on the case to line up the slots with the lower board...it might just work. I will talk to the chassis designer when he is in about doing this. Problem with this is it will take weeks and cost more money to get prototype pieces made. But still....could be worth it if we can then offer an SLI/Crossfire option for this case to other customers.
 

Ruger22C

Golden Member
Sep 22, 2006
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Okay, good luck.
You might want to do it just for this one build though, so you don't lose the $$ this one time, and so your customer can be happy with his SLI.
 

Silenus

Senior member
Mar 11, 2008
358
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BTW nice camera, what do you have?
I have T1i :)

First of all thanks for your help and suggestions! As everything sits now we are going to ship the system with one card. I may send the customer the second card just so he can run some SLI test with the cover off. It may turn our that SLI doesn't benefit him with his application and then we won't have to worry about it.

Camera is my trusty old Nikon D40. Lens is the Nikon 16-85 VR. And most importantly an SB-800 flash bounced off ceiling! Photography is actually my main hobby. I actually consider the above shots pretty quick and dirty...but good enough to show the problem. :p
 

ther00kie16

Golden Member
Mar 28, 2008
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Try SLI without the bridge. The performance would be somewhat lower than with the bridge but it will still give him an idea of the performance scaling.

Lowering the motherboard may not help because the bracket is still fixed in the same place. You'd have to mod the entire back of the case. Fastest way may be to physically shorten the bridge and contacts since it's just an electrical connection. I've never done it but it's theoretically possible.
 

Silenus

Senior member
Mar 11, 2008
358
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You know...I was thinking about SLI without the bridge. I don't like the idea but it might be worth a test.

Yes I would be lowering the motherboard AND getting new backplate made to accommodate the lower height (this would be done at the factory where the case is made so getting these parts changed is not actually difficult...just not something I could test right away). There is very little leeway, but perhaps just enough to accommodate going 1/16" to 3/32" lower. At this point we can't wait for that for our current customer. I am simply thinking about that for future use.

I think it would be kind of neat to promote and SLI/crossfire capable case in a small rackmount package. This case is only 16" deep and 5.25" (3U) high! It is also very quiet (not counting possibly loud video card fans :) )
 

alfa147x

Lifer
Jul 14, 2005
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Make sure you put a piece of tape or something so it doesn't short out against the door
 

Silenus

Senior member
Mar 11, 2008
358
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Make sure you put a piece of tape or something so it doesn't short out against the door

Indeed. I would not forget. :) We actually have some adhesive electrical insulating flim that I would stick to the under side of the case cover over the area of the SLI bridge.