PCIe Extension - feasible?

Discussion in 'Mac Pro' started by NOTNlCE, Jun 25, 2014.

  1. NOTNlCE macrumors 6502a

    NOTNlCE

    Joined:
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    #1
    Hey all-
    I just came across an opportunity to throw dual GTX 660s into my 3,1 Mac Pro, but I've got an issue to sort out before I pull the trigger. Currently, my 3,1 has 3 PCIe cards installed. In the main port, a dual slot GTX 660 OC 2GB Edition from EVGA, the second slot is empty and in 3 and 4 there is a Velocity Solo x1 and a BlackMagic Intensity Pro, respectively. My issue, of course, is that by installing another 660, I would need to REMOVE one of the existing PCIe cards, which I don't want to do. So my question is now this - is there a way to fit all these cards in my system by use of a PCIe extension cable, or something similar? Obviously the Solo x1 would be the card to be "hidden away" in the system, as it doesn't have ports I would need access to. At present, there is NO hard drive in the 4th bay, I was thinking I could rig up some kind of modification to hold the card up there, and then run an extension cable from the 3rd slot (the one that would be covered up by the second GTX 660) up to the card.

    Has anyone attempted something like this? Should I just forget about it and be happy with what I have?
    Any input is appreciated. Thanks as always.
    -N
     
  2. 666sheep macrumors 68040

    666sheep

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    Poland
    #2
    Didn't try, but it looks that there's enough space between the card and slot to fit flexible pcie extension ribbon.
     
  3. NOTNlCE thread starter macrumors 6502a

    NOTNlCE

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    #3
    I've been messing with the tower for a few hours, and I think it's probably doable. I would just need to jury-rig the Solo into a stable position, and it SHOULD be fine.
     
  4. mikeboss macrumors 65816

    mikeboss

    Joined:
    Aug 13, 2009
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    switzerland
    #4
    another possible solution: if you're using the 2nd GeForce only for CUDA etc you could place the second card in slot nr. 4 at the top. of course you would have to remove the 3.5" HDDs in slot 2, 3 & 4. I just checked this and it looks doable to me...
     
  5. NOTNlCE thread starter macrumors 6502a

    NOTNlCE

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    #5
    I'd want it for SLI under Windoze. With the Steam sale, a whole bunch of my friends are doing quite a bit of gaming, and I want to really rock my 5760x1080 setup.
     
  6. NOTNlCE thread starter macrumors 6502a

    NOTNlCE

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    #6
    To anyone who was curious - with the PCIe extension cables that I have tried, this is not feasible. The extension cable isn't flat enough to run behind a GPU. Attempting to install a GPU over top of a PCIe slot with the cable installed results in the GPU not being placed all the way into the slot. Looks like I'll need to put my capture card into a different slot. On a side note, twin GTX 660s is very nice.

    -N
     
  7. OS6-OSX macrumors 6502a

    OS6-OSX

    Joined:
    Jun 13, 2004
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    California
    #7
    A few questions: 1. Is your OS on the SSD connected to the velocity x1? 2. What’s on the hard drives in slots 1-3? If your OS is not on the SSD and you are using it just for speed, put 3 HD’s in slots 2-4 and software RAID 0. You can calculate the speed of that setup to see if it’s close enough. If not close enough, put 3 3G SSD’s in iceydocks and software RAID 0. Using 3G SSD’s because of the 3G connection of the MP. You can place the current SSD in the optical bay and run a cable from the logic board.
    If your OS is on that SSD, will the speed of 3G v. 6G adversely affect gaming if placed in the optical bay? Removing the Velocity solo x1 of course will give you the PCIe space needed.
     
  8. NOTNlCE thread starter macrumors 6502a

    NOTNlCE

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    #8
    My OS X install is a Fusion Drive based on the Solo x1 and a 1TB Hard Drive. However, it's not the issue. I have no desire to spend more on this machine and bother with RAID 0, and the spare PCIe slot would have gone to my capture card, not that important at this time. Sure, removing a card would obviously give me the space, but the effort isn't worth the results at the moment.
     

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