NEW: Octane X - is finally here! [MEGA FAQ THREAD] Tweet

[sszyszka]

I'm sorry if this has already been covered, I can't track it down. Will it be possible to use multiple eGPUs? I really kinda love the idea of my 13" MBP with 4 Pro VII's attached...

-Seb
http://sebastianszyszka.com

[cjadams]

This Card:
https://www.amd.com/en/products/professional-graphics/radeon-pro-vii
Though its very similar in specs to the Original VII and still Vega 20.. BUT its like 1800 bucks.. its their workstation equivalent just released in may.
No idea if they tested it though..you could get like 2 or 3 OG VII's for the price though.

[Goldorak]

I'm sorry if this has already been covered, I can't track it down. Will it be possible to use multiple eGPUs? I really kinda love the idea of my 13" MBP with 4 Pro VII's attached...

-Seb
http://sebastianszyszka.com

Yes, should work fine! I tested with 4x R7 on an iMac Pro for many months.

[cjadams]

So do a comparison without RTX on. and lets see more likely render times..

Super exciting and congratulations on the release!

Got a question.
I was curious and wanted to render the exact same C4D scene on my PC with two RTX 2070 Super and then using my 2019 MBP with a Vega 56 EGPU to see the speed difference.
Very far from a fair comparison since the PC setup got about 439OB and the Vega 56 currently got around 117OB. So the speed difference should be around 4x, probably more now since it's early days.

I rendered and the result of the final images are identical down to the pixel, very impressive.
However, the PC rendered the image in 2:15 and it took the MBP 75:12. So PC was around 33x faster.

Is this due to the PC being much more powerful with more memory and better CPU or is an EGPU solution just that much slower?
Guessing there's a lot of lost performance with EGPUs.

Was RTX on and did you have to go out of core on macOS? Those two factors could easily affect speed depending on the scene and kernel settings used.

Don't think I went out of core but RTX was indeed active, that's probably why.
Thanks for the reply and congrats again, really excited to be able to bring Octane on the road.

[james_conkle]

In regards to multiple eGPU - you might want to wait before adding more than 2 eGPU since both the iMac Pro and MacBook Pro only have two thunderbolt controllers. That means once you go over two eGPU (or plug 2 eGPU in the same controller) you're splitting the bandwidth.

https://barefeats.com/iMac-Pro-Four-GPUs.html


It'll work but real world performance might take a hit.

[sszyszka]

Yes, should work fine! I tested with 4x R7 on an iMac Pro for many months.

Fantastic! Thanks! Did you notice any performance hit with 4 vs. 2 as james_conkle mentions? (Assuming you tested with fewer than 4)

-Seb
http://sebastianszyszka.com

[cjadams]

The good news is that with compute versus playing video games the amount of data that's being shuffled is a lot less than trying to keep up with frame rates. So in theory we should be able to do fairly well but not lose a lot of performance even if we use up two cards on both buses. I think any comments from people who've actually done it would be good. I don't have enough GPUs here to test. I remember this being part of a discussion on bandwidth limitations with the eGPUs on a forum some other place (egpu.io) maybe...I can't find the link at the moment.

[sszyszka]

The good news is that with compute versus playing video games the amount of data that's being shuffled is a lot less than trying to keep up with frame rates. So in theory we should be able to do fairly well but not lose a lot of performance even if we use up two cards on both buses. I think any comments from people who've actually done it would be good. I don't have enough GPUs here to test. I remember this being part of a discussion on bandwidth limitations with the eGPUs on a forum some other place (egpu.io) maybe...I can't find the link at the moment.

That's one of the things that crossed my mind. I do think I recall something along those lines being posted on egpu.io, but I don't recall whether a distinction was made in how the GPUs are being utilized. I'm no expert, but my guess is the bus utilization for compute is more "bursty" than gaming.

Being a Mac user I've had little interest in GPU rendering and am coming into all this way behind the curve. So if anyone is inclined to correct me, have at it. I'm here to learn.

-Seb
http://sebastianszyszka.com

[cjadams]

Yeah.. there is a slight learning curve.. I'm still figuring out if I need to have monitors attached and or ghost headless dongle or not..
I think most pro programs like DaVinci and RS/Octane seem to just work and find the devices. But would be good to know if that's needed or not.

[joenyc]

Juanjo is updating octane X studio for houdini, it will be on the list shortly. Sorry about that. The enterprise build is there.

Is there an estimate for when Houdini X plugin will be released for Studio? Wondering if it's worth upgrading to Enterprise to get access if it's going to be a while. (Related: is it possible to upgrade a subscription, or do I need to cancel one and buy the other? I couldn't find a way to do it on the site.)