Two GPU limit over single thunderbolt bus
 
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Two GPU limit over single thunderbolt bus  

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mcarver316
(@mcarver316)
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Joined: 3 years ago
 

This might seem just complaining, but there are plenty of applications that require laptop only (or minimal/compact equipment) and multiple GPUs.

In my recent journey with multiple GPUs, Thunderbolt and Windows, it seems two GPUs are the maximum over one thunderbolt bus. At least with MSI hardware (GT80S, GT73Vr) with built-in dual discrete GPUs.

I've ordered a Clevo 870DM3 with 2 thunderbolt ports. I'm not completely sure that I will be able utilize 2 Akitio Nodes (I'm also considering the Sonnet Breakaway Box due to its slightly smaller footprint than the Node) or maybe even 2 Cubix with a 1080 Ti and 780 Ti in each (see my other post on GPU pairing compatibility).

An eGPU.io member suggested the Cube3, which accepts up to 4 double wide GPUs. I am leery that I will only be able to use 2 GPU before Windows rears its ugly error code 12 head. Good thing with Cube3 is it can be ordered with thunderbolt, thus eliminating the need for an eGPU such as the Node to act as PCIe adapter. Another option is two Cube2s (which accepts 2 double wide GPUs with a single slot to spare) via 2 thunderbolt ports in the Clevo if Windows will allow such a setup.

I will update this post once I receive the Clevo 870DM3 (yes, I ordered the dual 1080 variety).

2015 17" MSI GT73VR-6RF 2xGTX1070 + [email protected] (AKiTiO Node driving Cubix Chassis) + Win10 > 365Gigahashes per second


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Sky11
(@sky11)
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Joined: 3 years ago
 

Hi Mcarver,

What applications in your opinion require multiple GPUs? Do you have any indication of reasonable performance scaling of multiple eGPUs over Thunderbolt?

Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts


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mcarver316
(@mcarver316)
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Joined: 3 years ago
 

Ooops..I misunderstood your question.

Thunderbolt scales terribly at the moment, at least when compared with native PCIe.

As for applications and multigpu- they were poor choice of words, thanks for pointing that out. What I really meant is projects that make extensive use of PCIe, which is not limited to GPUs.

2015 17" MSI GT73VR-6RF 2xGTX1070 + [email protected] (AKiTiO Node driving Cubix Chassis) + Win10 > 365Gigahashes per second


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mcarver316
(@mcarver316)
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Joined: 3 years ago
 

Looks like Clevo only implemented two TB ports over one bus...oh well. Yes, this means more or less same limitation as having only one port. Well, at least now I can stack 2 Aki Nodes or manufacture my own 2 GPU case with dual Aki Node controllers lol.

http://forum.notebookreview.com/threads/official-clevo-p870km1-p870km1-g-sager-np9876-owners-lounge-phoenix-3-0.800081/page-22

 

2015 17" MSI GT73VR-6RF 2xGTX1070 + [email protected] (AKiTiO Node driving Cubix Chassis) + Win10 > 365Gigahashes per second


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Sky11
(@sky11)
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Joined: 3 years ago
 

I have seen a system which was able to light up 2 eGPU boxes with AMD graphics cards, and all GPUs in the system were functional. However, XConnect was designed to handle only one eGPU at a time, so you have you be careful on unplugging 2 eGPUs from the laptop.

Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts


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mcarver316
(@mcarver316)
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Joined: 3 years ago
 

All my cards are NVIDIA. Other than Windows retarded error code 12, the Geforce cards for the most part, are plug and play.

2015 17" MSI GT73VR-6RF 2xGTX1070 + [email protected] (AKiTiO Node driving Cubix Chassis) + Win10 > 365Gigahashes per second


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mustardseedsg
(@mustardseedsg)
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Joined: 2 years ago
 
Posted by: mcarver316

This might seem just complaining, but there are plenty of applications that require laptop only (or minimal/compact equipment) and multiple GPUs.

In my recent journey with multiple GPUs, Thunderbolt and Windows, it seems two GPUs are the maximum over one thunderbolt bus. At least with MSI hardware (GT80S, GT73Vr) with built-in dual discrete GPUs.

I've ordered a Clevo 870DM3 with 2 thunderbolt ports. I'm not completely sure that I will be able utilize 2 Akitio Nodes (I'm also considering the Sonnet Breakaway Box due to its slightly smaller footprint than the Node) or maybe even 2 Cubix with a 1080 Ti and 780 Ti in each (see my other post on GPU pairing compatibility).

An eGPU.io member suggested the Cube3, which accepts up to 4 double wide GPUs. I am leery that I will only be able to use 2 GPU before Windows rears its ugly error code 12 head. Good thing with Cube3 is it can be ordered with thunderbolt, thus eliminating the need for an eGPU such as the Node to act as PCIe adapter. Another option is two Cube2s (which accepts 2 double wide GPUs with a single slot to spare) via 2 thunderbolt ports in the Clevo if Windows will allow such a setup.

I will update this post once I receive the Clevo 870DM3 (yes, I ordered the dual 1080 variety).

On my MacBook Pro 2017 and the Cube3, I can only run 2 cards on a single TB bus. Adding a third card results in kernel panic. So if you get the Cube3 the only benefits are ample space for cooling and x2 PSUs. The rest of the slots can also be used for other PCIe cards if needed. 

15” MBP 2017 w Touch Bar, OS X 10.13.6, Mantiz Venus w GTX1080. OWC Helios w GTX1080. OSS Cube3 w GTX1080.


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