Divinci Resolve With Cubix GPU Xpander

[Jesse Korosi]

I am just curious if anyone out there has got there hands on the Cubix GPU-Xpander to use along with Divinci Resolve yet?

Will this speed up renders as well or just the playback/realtime performance of your color grading experience?

I am currently running Divinci on a MacPro with the Quadro FX 4800 along with a RedRocket. But I am curious if I would get better performance for specifically Rendering if I were to add another rocket ... or two, or another Quadro FX card?

Thanks in advance!

[Steve Johnson]

Jesse,

I spoke to a company here in the UK called jigsaw24 about this and got talking with one of the techies. I asked how much to full 4K playback etc you could get if you added the expander box with 3 Quadro 4000 cards as per the spec on the website.

He said that they where talking directly on a weekly basis with the guess test Davinci for Mac and with the expander box and 3 Quadro 4000 cards, they where getting full 4K half debay with 24 nodes, so I would get you could get 4K Full debay with 12 nodes.

You might want to get that checked independently but thats what I was told.

Hope that helps.

Steve

[Nick Shaw]

…they where getting full 4K half debay with 24 nodes, so I would get you could get 4K Full debay with 12 nodes.

I don't think that logic works. Apart from anything else, 4K is four times as many pixels as 2K, not twice as many.

[Jeff Kilgroe]

I don't think that logic works. Apart from anything else, 4K is four times as many pixels as 2K, not twice as many.

Correct. 4X the amount of calculations for the demosaic / debayer operations to go from half to full debayer. Not sure how that would translate to overall performance as there's a lot of other things going on as well. But I would say that it's going to be less than just half as fast.

[Steve Johnson]

Correct. 4X the amount of calculations for the demosaic / debayer operations to go from half to full debayer. Not sure how that would translate to overall performance as there's a lot of other things going on as well. But I would say that it's going to be less than just half as fast.

It would be interesting to see on a system that actually is running using the expansion box and the extra 4000's to see exactly what you can get out of them in terms of what resolution vs what debayer vs how many nodes!

[Steve Johnson]

I don't think that logic works. Apart from anything else, 4K is four times as many pixels as 2K, not twice as many.

Hi Nick

Yes i would agree with you on that logic. That is what I thought at first but that's what these tech guys told me. Never believe a tech guy! ;-)

Steve

[Jesse Korosi]

Hey Steve,
Thanks for the response!

That is awesome. But I am not getting a 4K monitor ANYTIME soon. haha My main concern was whether or not I could speed up rendering specifically if I had the Cubix.

One of my co-workers was just told by a Divinci Rep today that we would be best served to go with a 12 Core Mac if we were to mainly use it for transcoding.

"The GPU will make it faster but when working with compressed formats the CPU
plays a greater role.

So if you were going DPX to DPX I would say yes as many GPU's as possible
but if you had to pick between CPU or GPU additions with h.264 etc I would
say go 12 core CPU"

[Steve Johnson]

Hey Steve,
Thanks for the response!

That is awesome. But I am not getting a 4K monitor ANYTIME soon. haha My main concern was whether or not I could speed up rendering specifically if I had the Cubix.

One of my co-workers was just told by a Divinci Rep today that we would be best served to go with a 12 Core Mac if we were to mainly use it for transcoding.

"The GPU will make it faster but when working with compressed formats the CPU
plays a greater role.

So if you were going DPX to DPX I would say yes as many GPU's as possible
but if you had to pick between CPU or GPU additions with h.264 etc I would
say go 12 core CPU"

Hi Jesse

No problems - hope it was some help.

Steve

[Chris Parker]

also, as i understand, the GPU expansion helps only with applying color fx or nodes on an uncompressed image (eg. 2K DPX). But if your source material is compressed (eg. QT) then it is CPU power you need more than GPU power.

and that the gpu expander won't work any magic on render times.

if you are needing to have more nodes applied to 2K DPX files and maintain realtime playback and monitoring, this is where the multi GPU comes in.

is this correct?

[Steve Johnson]

also, as i understand, the GPU expansion helps only with applying color fx or nodes on an uncompressed image (eg. 2K DPX). But if your source material is compressed (eg. QT) then it is CPU power you need more than GPU power.

and that the gpu expander won't work any magic on render times.

if you are needing to have more nodes applied to 2K DPX files and maintain realtime playback and monitoring, this is where the multi GPU comes in.

is this correct?

Chris,
So does that not make the case to work in an uncompressed format on Davinci for Mac? So by that rational, correct me if I am wrong, if you work in r3d files, which are not compressed (e.g. QT) is that not better as you would have all the RAW data, so therefore the GPU expander would work. Is that right?