2012 Mac Pro (GTX980Ti) [1st,12C,X] + GTX 780 Ti x3 @ 64Gbps-PCIe (Cyclone Backplane) + macOS 10.11.6 [hoeveler]
Hey Hoeveler! Well, it took seemingly forever, but I finally found and acquired a PCIe2-427 backplane and accompanying PCIe2-426 HBA. The x16 cable was actually the hardest thing to find w/o paying a ridiculous $300 for one. I got a basic case— not a fancy one like you, but I mainly wanted to keep it small and inexpensive. Also got a 600W PowerSpec power supply from Micro Center.
I'm having trouble getting the chassis to connect and show up, but I think it is mainly down to getting the power connections right on the 427 board. Your PDF above is a Dropbox public link, which no longer works, so I'm unable to refer to your documentation...but I wondered if this might be obvious to you. Referencing the diagram on p16 of the 2707 user manual here:
and my power supply's specs here:
do you have any suggestions or guidance for how to connect? I have posed this question to Cyclone, but not sure if they'll want to help me, since I'm not buying a $3K turnkey system... Here's what I sent:
I am configuring an installation of a PCIe2-427 & PCIe2-427 pair in a custom enclosure. When connecting the 427 to the host via the 426, I get a red power LED on the 427 board and my 10GbE card shows power, but I get no green link light on the back, and no host visibility of expansion cards connected to the 427.
I have the main power supply 24-pin feed connected at J13, as well as the 4-pin processor feed at J10. ...I know that J11 is for PCIe card aux power (such as for a GPU), but I can find no mention of J9 anywhere. I believe this might also be referred to as “12V-3”. A photo on your site shows what appears to be an 8-pin power lead connecting to J9, but my standard ATX power supply doesn’t appear to have a matching connection…unless this is an *input* PCIe aux feed for J11 (I *do* have some 6+2 PCIe connectors on my PS). I have tried jumpering J21 and J22 as well to engage the resistors, but this doesn’t appear to change the behavior I’m seeing.
Any idea what I should be connecting at J9? Table 3-3 on p11 suggests it's pretty important, as it supplies 12V to the baseboard. Sorry to be dumb about this...I don't normally build PCs from scratch, much less specialized boxes like this!
Meant to follow up on this a long time ago for anybody using this thread as a reference... I was able to get my custom Cyclone PCIe2-427 solution powered up and working by "ganging" the two 4-pin connectors into the 8-pin J9. Here's the response from Cyclone (who were awesome to help me out, and if you want turnkey stuff, definitely give them a shout):
Cyclone: The issue is that he needs to have a power supply connected to the 8 pin aux. 12V power connector (CPU pinout).
The 8 pin connector (J9) supplies power to the on-board circuitry (hence the red power LED being lit).
The main connector (J13) gets 12V to slots J1 and J2.
The 4 pin connector (J10) gets 12V to slots J3, J5, and J7.
The 8 pin connector (J9) gets 12V to slots J3, J5, and J7 and the on-board circuitry.
The power distribution was setup to split the the 12V power across multiple power supply rails.
Both J9 and J10 use the CPU-style pin-out (as opposed to the PCIe add-in card/GPU 12V aux. power pinout)
FT: my power supply actually has two of those 4-pin CPU connectors as one “bunch”, nearly joined all the way to the connectors. I was using just one of them in J10. Should I undo that one and put the pair into J9?
Cyclone: If the two 4 pin connectors are "gangable" with an interlocking plastic tab to create an 8 pin configuration, I would suggest doing that and plugging it into J9. That would give you 12v power to all the slots and to the backplane circuitry.
Super cool to be able to do this! Thanks to hoeveler for his thread/input and Cyclone for their technical advice!
Wow Fred, sorry I missed your reply back in November! I’m glad you got it working. I didn’t have the same problem because I was able to get my PSU connected to the backplane on all the connectors.
GPU performance has been scaling every GPU generation. By comparison, Intel's CPUs have had marginal performance increases. This older system would make a good barebones candidate to boot the OS & run multiple eGPUs for processing on an Apple platform, and bypass Thunderbolt altogether.
Wow! I had no idea! (...and so very Apple of them to do so...)
Here's that pdf... and I will update all that info into a new post, but here's the old one:
Hey Hoeveler can you confirm how many GPUs you have gotten working and on which os version? I thought the current macOS will only address 3 total.
Hi! I had one GPU internal to the cMP and 3 GPUs on the backplane. I would have been able to fit one more on the backplane but at the time it was mounted inside the Phanteks case. I’ve since moved the backplane onto a wall-mounted Thermaltake Core P3 case where I can fit one more GPU at the bottom edge of the backplane.
so wait - you do have four gpus working? In what version of macOS?
I had 4 GPUs working in OS X 10.11.6 El Capitan. But I have since switched this system over to Windows as my main machine because Apple kept changing everything and I have work to get done. 😉 I still have and love my cMP system as my file server and my wife uses that machine for Lightroom. I stopped bothering to force Apple’s old and awkward hardware to do GPU rendering.