A really weird situation on 128 core computer


#1

I tested same process on diferent computers
6 ndi 1080p videos at same time

the CPU usage result are:
intel 2683v3(14x2G) 36-42
intel 2618L(8x2.3G) 35-40
amd 1700x(8x3.4G) 19-23
amd 3800x(8x3.9g) 18-21
amd 1950x(16x3.4g) 13-15

these looks make sense, and seems like the frequence are more important than total power

but I get a super weird result on a 128 core computer (2 CPUs, each 64c/128t)
its about 42%, worse than all above…
the only thing that could cause this problem I think is the frequence (or numa problem), but still wired for this high CPU usage


#2

Memory channels and base clock are a priority. For example, a 7900X with a 3.3Ghz base clock and 10 cores is a good balance on the Intel side. It can reach a sustained >4Ghz with many active cores with a good water cooler as some of the AMD models you listed.
Performance is not linearly scalable, as you said NUMA is a factor for slow performance on highest end CPUs.


#3

y, that is also what I get from these results
I will be needing a high clock CPU than a lot of cores, I just searched and think i9 9900KS or AMD 3960X might be the best balance choices with cores and clocks


#4

yes, and this is true for many video-broadcast softwares, not only CasparCG. 9900k is the best choice atm for me after testing some AMDs.


#5

Hi,

In general, CasparCG Server has poor support for dual CPU as is today. This has not been something we have been working on or focusing at because we can’t find a use case for it really. You can always create a feature request at GitHub

Best regards,
Armin


#6

I successfully run multiple instances of CasparCG on dual CPU systems. That worked also with dual GPU‘s tied to the CPU‘s.


#7

Yes it’s possible but it’s not optimized for it as far as I know. I haven’t tried to run dual GPU’s, how has your experience been with that out of curiosity?


#8

I made a studio decor with a lot of outputs. We had two systems with fual CPU, dual GPU and dual Decklink Quad. Running rhem from one instance was only working for about 6 channels. Using 2 or 3 Caspars left us with 6 channels for each instance. So that was quite suprising. I used 2.0.7 for this, as there were a few Flash templates involved. If you come to Switzerland I will show the installation :grinning: