2012 Mac Pro (GTX980Ti) [1st,12C,X] + GTX 780 Ti x3 @ 64Gbps-PCIe (Cyclone Backplane) + macOS 10.11.6 [hoeveler]
Hello all! I am new to this site, but I wanted to share my unusual setup, and my surprise that I have not seen a single other eGPU build based on used PCIe backplane expansion systems like mine from Cyclone Microsystems or Magma. If you do go searching around, be SURE you're looking at PCIe, not PCI.
- Cyclone Microsystems ATX-sized backplane model PCIe2-427 - found on ebay for $200
- Cyclone Microsystems PCIe host bus adaptor model PCIe2-426 - found on ebay for $120
- Molex X16PC - PCIe x16 server connection cables - found on ebay for $30
- Corsair AX1200i 1200-watt power supply - found on ebay for $182
- Nvidia GTX 780Ti Founders Edition (x3)
- Phanteks Enthoo Evolv ATX case (tempered glass special edition 😉
- 2012 Mac Pro 5,1 ("cheesegrater" cMP) upgraded to 3.33GHz dual 6-core X5680 Xeon
- 64GB RAM
- 256GB Samsung SM951 M.2 AHCI boot SSD mounted on an Angelbird Wings PX1
- EVGA GTX 980Ti Founders Edition
Because my cMP has native PCIe slots (Apple, what were you thinking getting rid of those?!?), compared with what I am seeing about having to run drivers and crazy shenanigans to get the TB ports to talk with the PCIe slots on others' eGPU builds, I was surprised to find that all I needed to do was plug the host bus adaptor into the second x16 slot on my Mac Pro motherboard, plug the molex cable into that, and plug the other end into the backplane, apply power to the backplane, plug my GPUs into the backplane, and boot the computer! Because this is a managed/actively switched PCIe adaptor, the OS only sees the PCIe slots as an extension of the existing PCIe bus, just like plugging a USB hub into a USB port!
Also, with a little bit of shopping around, these rare backplanes CAN be found for less than the price of the AKiTiO boxes and other such contraptions. Of course, if you have a nMP ("trashcan") or a laptop, you'll still have to go through the process of getting your AKiTiO box up and running via your Thunderbolt port, but once you do, you can further extend that SINGLE PCIe slot into an entire array of GPUs. There is one backplane currently available on ebay for only $100 more than I paid for my 5-slot ATX sized board, which can run up to 16 GPUs if you went single-slot on your GPUs or used riser cables to extend the PCIe slots.
I'll post some more current photos later today, but here's a link to a PDF I put together that's about all the upgrades I did to my classic Mac Pro 5,1 - not just this eGPU addition & .
I have since added the M.2 boot drive and added more GPUs to my rig, but other than that it's about the same.
Hoeveler, this is great stuff. Thanks for posting. The backplane manufacturers haven't done a good job of getting the word out. This is a wonderful solution that not many people are aware of.
MP 6,1 | 4c | d700
MP 6,1 | 6c | d500
Thanks! I think these backplane manufacturers don't want to cannibalize their $3000+ turnkey system sales. What I built for less than $500 they sell for $3000 and up.
I just discovered yesterday that a seller on ebay has released "over 10 available" of these hard-to-find boards. Here's the link: http://www.ebay.com/itm/262895086097 NOTE: this model of board is the big brother to mine, and will hold 8 GPUs. BUT in addition to the host bus adaptor card, you'll need this daughter card: http://www.ebay.com/itm/262885434236 There is another model as well that can hold 16 GPUs IF you set it up with riser cables and such, to route the slots out from under the single-slot mounted slots.
For anyone who's already built an eGPU rig from the guides on this site, keep in mind that you should view this as an extension of what you already have. What I mean is that if you put the host bus adaptor card into your PCIe slot on your eGPU, then you should be able to further extend that signal out to the backplane and run up to 16 MORE GPUs for GPU rendering.
Thanks for the post and info. I'm not quite as interested in eGPU applications specifically as I am simply having some more PCIe slots for my Mac Pro to utilize. So I found your thread via search. I'm looking all over eBay to try to locate the components you listed, but there are very few PCIe2-426s (and they are closer to $200), and no PCIe2-427s or Molex X16PC cables. I also cannot find many (or any for the latter 2 items) completed listings w/ these components either. Did you acquire and assemble these items a while back? Any suggestions on other places to find them?
These are indeed somewhat rare to find on ebay. However, you're in luck, since there are a bunch of similar backplane available right now on ebay that have 8 slots, but the only catch is they aren't the ATX size, but are more server size.
Also, that seller has a bunch of the host adapter cards... One more catch with this larger 8-slot board is that they need a daughter card that goes into the backplane. It doesn't have the molex receptacle built in like the ATX size one does. Take a look at the block diagram from this page and make sure you get all 3 parts, not including the cable.
Thanks, hoeveler, for the quick reply! Yeah, I was looking at those linked from your 3/15 post, but I think those would be overkill and overly large for what I'm wanting, not to mention more expensive, due to the higher cost of the board plus needing the extra "daughter card". This is more of an enthusiast/prosumer-level build than something all-out professional/industrial...I really just need an extra slot or 3 because mine are full, so a smaller ATX form factor in a reasonably sized case like you did is what I'm after.
So, what do you think? Just keep waiting to see what pops up? How long ago did you score your parts? I'm guessing a while back, since I don't see any under "completed" either...
I got mine about a year ago. I just happened to search on ebay after doing some research. I was almost going to let the ebay auction pass me by, but I decided to go for it and try it out. I'm glad I did, because I haven't seen another one become available since then. But keep a google alert and/or an ebay search alert going and eventually something will come up. You might also search for the Magma brand backplanes. Just be SURE you're buying PCIe, not PCI. There are lots of old PCI expansion chassis out there and you don't want to make that mistake thinking you're getting a killer deal. 😉