External PCIe expansion (non TB3)

[trispembo]

Awesome thread! Thanks for providing a great resource.

Looking to expand my Mac Pro 5,1 with two more GTX 1080 Ti (total 3, maybe 4) and some more data storage for DaVinici Resolve. I've already installed the Pixlas mod to power the internal 1080 Ti in PCIe slot 4.

I've managed to get hold of a Cyclone PCIe2-427 backplane and cable. The supplied HIC is a Dell C10F001 which has a PLX chip on board. I have it installed in PCIe slot 2 (x16) of my Mac Pro 5,1, but MacOS 10.13.6 doesn't "see" anything occupying that slot.

Has anyone here managed to successfully use that HIC, or should I be getting a Cyclone PCIe2-426 card?

Couple more questions..
1. I have a 1200w PS feeding the 24-pin ATX power connector. However, on the 427 backplane board there's a few power connectors with nothing plugged in (J10, J9, J11) - should there be something plugged into those from the PSU?
2. The fans in my case are all 3-pin. The fan connectors on the 427 backplane are 4-pin. Looks like they connect ok, but will they still work ok? Presuming the backplane has heat sensors which tell the fans when to spin up, but just want to make sure I'm doing things right and not going to overheat my components.

Any help would be appreciated.

 

[joevt]

Awesome thread! Thanks for providing a great resource.

Looking to expand my Mac Pro 5,1 with two more GTX 1080 Ti (total 3, maybe 4) and some more data storage for DaVinici Resolve. I've already installed the Pixlas mod to power the internal 1080 Ti in PCIe slot 4.

I've managed to get hold of a Cyclone PCIe2-427 backplane and cable. The supplied HIC is a Dell C10F001 which has a PLX chip on board. I have it installed in PCIe slot 2 (x16) of my Mac Pro 5,1, but MacOS 10.13.6 doesn't "see" anything occupying that slot.

Has anyone here managed to successfully use that HIC, or should I be getting a Cyclone PCIe2-426 card?

Couple more questions..
1. I have a 1200w PS feeding the 24-pin ATX power connector. However, on the 427 backplane board there's a few power connectors with nothing plugged in (J10, J9, J11) - should there be something plugged into those from the PSU?
2. The fans in my case are all 3-pin. The fan connectors on the 427 backplane are 4-pin. Looks like they connect ok, but will they still work ok? Presuming the backplane has heat sensors which tell the fans when to spin up, but just want to make sure I'm doing things right and not going to overheat my components.

Any help would be appreciated.

There's a PLX switch chip on the back plane (PEX 8680). A host interface card doesn't have a PCIe switch. The picture in the manual says it's a repeater. That means it's a redriver or a retimer.

http://www.cyclone.com/pdf/600-2707.pdf

PCI Express® Retimers vs. Redrivers: An Eye-Popping Difference - Astera Labs

Retimers and Redrivers both provide different capabilities in PCIe 4.0 and 5.0 systems. Learn about the differences between the two.

www.asteralabs.com

While downstream PCIe slots have a standard, I don't think the same can be said for upstream PCIe slots - which means not all HIC cards will work.

3 pin fans will work when connected to 4 pin connectors.

Three-wire and four-wire CPU fans, what's the difference?

What is the difference between 3-Wire and 4-Wire CPU cooling fans? Of course, the obvious answer is “1 Wire!” :-)

superuser.com

Manuals for other Cyclone backplanes state that while the connectors are 4 pin, there is no PWN (did they mean PWM?) circuitry so you might as well stick with 3 wire fans.

http://www.cyclone.com/pdf/600-2712.pdf

http://www.cyclone.com/pdf/600-2720.pdf

J11 is for a third PCIe aux power connector. The other jumpers:
2012-mac-pro-51-cmp-gtx980ti-3x-gtx780ti-cyclone-microsystems-backplane-host-bus-adaptor-win10-or-os-x-10-11-6-el-capitan
You should verify with Cyclone.

 

[startergo]

Manuals for other Cyclone backplanes state that while the connectors are 4 pin, there is no PWN (did they mean PWM?) circuitry so you might as well stick with 3 wire fans.

I am wondering why my PWM fans run at full speed. I thought it was because not all slots are populated:

"Because the power supply has been sized for a fully populated chassis, when in placed under light loading, the supply may not stay in regulation. Symptoms of a supply that is not regulating properly are loss of link back to the host (green “CABLE” LEDs are not ON) or a chassis that powers up momentarily, then turns OFF. To hedge against this situation, the PCIe2-427 has on-board load resistors that can be jumpered into service. Users can selectively load the +12V1 and +12V2 rails as required for their application. The +12V1 rail services slots J1, J2 and the six position PCIe auxilary power connectors. If these slots and connectors are not used or are lightly loaded, then install the jumper shunt across the pins of J21. The +12V2 rail services slots J3, J5 and J7. If these slots are not used or are lightly loaded, then install the jumper shunt across the pins of J22."
[automerge]1582719079[/automerge]

Has anyone here managed to successfully use that HIC

I have this board but my cable is Nvidia if I am not mistaken I have to verify. Works fine.

 

[trispembo]

Thanks very much for the extra information gentlemen, that's nailed it. Got the system up and running!

 

[trispembo]

Ok, my second GTX 1080 Ti finally arrived and I've installed it on the Cyclone PCIe2-427 backplane.
However, now I'm starting to get glitches in the display.

Moving Finder window ends up leaving a streak across the screen Chrome is not rendering websites properly and everything is a little sluggish.

I have a EVGA GTX 1080 Ti FE (MacVid flash) in slot 4 (Mac Pro 5,1) and EVGA GTX 1080 Ti FE in J7 in the backplane. Just to see what would happen, I removed the 1080 Ti from the backplane and installed my older GTX 980. Same problem occurs. Remove the second card, and everything works fine.

System Report can see the card. I've got the current NVidia GPU & CUDA drivers on 10.13.6.

Others are reporting successfully using more than one GTX GPU in the Mac Pro 5,1.. so what's going on? I've done a quick search online but can't find anyone with he same problem.

 

[Le_Cactus]

Ok, my second GTX 1080 Ti finally arrived and I've installed it on the Cyclone PCIe2-427 backplane.
However, now I'm starting to get glitches in the display.

Moving Finder window ends up leaving a streak across the screen Chrome is not rendering websites properly and everything is a little sluggish.

I have a EVGA GTX 1080 Ti FE (MacVid flash) in slot 4 (Mac Pro 5,1) and EVGA GTX 1080 Ti FE in J7 in the backplane. Just to see what would happen, I removed the 1080 Ti from the backplane and installed my older GTX 980. Same problem occurs. Remove the second card, and everything works fine.

System Report can see the card. I've got the current NVidia GPU & CUDA drivers on 10.13.6.

Others are reporting successfully using more than one GTX GPU in the Mac Pro 5,1.. so what's going on? I've done a quick search online but can't find anyone with he same problem.

Hi when I was Under 10.3.6 with two Nvidia GTX 1070, there was only a driver who worked with multi gpu.
378.10.10.10.25.106
CUDA 387.128

 

[bsbeamer]

Believe all of the 387.XX.XX.XX.XX.XXX series drivers have issues with multiple GPUs in some capacity. Would not recommend anything higher than macOS 10.12 for multiple NVIDIA GPUs.

 

[Le_Cactus]

Trispembo, you can try
378.10.10.10.25.106
CUDA 387.128

 

[trispembo]

Thanks.

Reason I need MacOS 10.13 is because DaVinci Resolve 16 only works with 10.13 +. I'd stick with DR15, but it doesn't support the new Blackmagic RAW codecs my cameras capture. So, if I can get this to be stable it'll be my setup for quite a while.

If I can't get it to be stable, I'll probably have to sell my 2 x 1080 Ti and invest in something like Radeon VII.

I just installed 378.10.10.10.25.106 & CUDA 387.128

That certainly fixed the GUI problem, and everything seems to be responsive with 2 x 1080 Ti installed.

Unfortunately DR16 doesn't recognise there's a CUDA compatible GPU installed and defaults to Metal (which is much slower). So I installed the latest CUDA 418.163 and DR16 fires up fine. Just running an export now and it seems to be stable and slightly faster than with single 1080 Ti.

I'll do some more testing, but so far so good. Thanks for your help.

EDIT: Been running the machine for 24 hours now - doing intensive Exports/Rendering of a huge documentary project. Everything seems very stable and responsive. Thanks Le-Cactus, you've saved me a world of pain and given me hope there's still life left in this old Mac Pro 5,1 beast!

 

[Le_Cactus]

Hi all,

I've a friend who's searching a Cyclone PCIE 2.0 x16 Expander for his Mac Pro 5.1, is-it easily foundable?

I don't know, if it's still interesting.

Thanks.

 

[startergo]

It is perfect even for a PC. Instead of trying to fit these wide cards in the PC or the cMP it is much easier to use the expander. Also, you don't need any power cable modifications in the cMP. I am using mine on both the cMP and the PC.

 

[Le_Cactus]

Thanks for your answer startego , I own one.

But these expanders aren't easy to buy, they are very rare on the second hand market ...