new computer build

[rustywoods]

Hello all,

I am going to be building a server/computer to do DCP-o-matic tasks and sometimes I might make it a DCP-o-matic Encode server

my processor will hopefully be a Threadripper 2 2990WX, is this the best processor to go with because it has 32 cores or is the AMD Ryzen Threadripper 2950X better for DCP-o-matic because it has a higher Passmark? cpubenchmark

basically what is the most efficient processor for DCP-o-matic - intel and AMD options are fine?

i hope you can help?

thanks in advance

[Carsten]

Clearly, the more cores, the better. Unfortunately, AMDs Ryzen CPUs so far are not dual CPU capable, so, having a 32core CPU clearly is an advantage over a single 16core CPU when running DCP-o-matic.
So far, a Threadripper should make the best and low cost single CPU system for DCP-o-matic.

If you have built a 2990WX system, don't forget to submit a benchmark!

https://dcpomatic.com/benchmarks/fps

- Carsten

[rustywoods]

Thanks for getting back to me Carsten,

I will 100% send you guys my benchmark cause if I need it, someone else will need it for sure

I was tempted to get a epyc dual core motherboard and get one cpu now, one later but as it's £1000 more for the system alone, so I may as well build 2 threadripper systems.

Quick question is RAM size important? I was going to get 32GB as I have a feeling DCP-o-matic is just more processor reliant than RAM size.

[Carsten]

RAM may become important when using many cores, and especially when doing 4k. However, I doubt anyone would actually setup a system with 32 cores and 8GB RAM. I can't give you exact numbers like x GByte per core - but I regularly use 24-36 threads on my dual CPU 24core machine with 12GB RAM only, and don't get into trouble. Not even when I tried 48 to 64 2k threads, so...

- Carsten

[rustywoods]

Hello,

So I have bought a 32 core processor with 16gb ram and a 1tb m.2 drive

and have downloaded the Big_Buck_Bunny trailer at 854x480 and am building it into a 24fps DCP.

it is encoding at 8.6 fps (max) any idea why it's slow?

[Carsten]

Oops, that is dead-slow. Now, for that kind of machine, BigBuckBunny is not a suitable test anymore - on fast machines, it will typically complete within a few seconds. Sintel is better (also because the content resolution matches real applications better).

Go to DCP-o-matic general preferences and check how many threads are set there. Does this machine run under windows? Open TaskManager-> and check how many logical CPUs the OS has detected, and, while encoding, check their load.



- Carsten

[rustywoods]

Hi Carsten, Thanks for getting back to me

yeah it's not great results

Only 14-15 frames on Sintel (2048 x 872 (270 Mb, mp4, 5.1) I checked the thread usage before i set it off and it was 64 threads.

I've attached a screen grab of taskmaster and dcp-o-matic in the background and you can see the low frame rates and yes i am using Windows 10

[Carsten]

Strange. Try to make runs with a setting of 32 threads and 100, just to see what happens.

There is a Ryzen 1950X benchmark result with 24+ fps with Sintel.

Maybe you can supply a log of an encoding (Bunny should suffice) to Carl. Go to advanced prefs and check all log options before running it.

- Carsten

[Carsten]

There is a known memory bandwidth issue with the 2990WX. I doubt that DCP-o-matic is exceptionally memory bandwidth hungry during encoding, but you may look for some internet sources dealing with dual vs. quad channel configurations. Do you have two or four memory sockets populated?

- Carsten

[rustywoods]

I have 4 sticks of ram of 2 different sizes in slots A1,B1,C1 and D1 - still only doing 11fps


none in slot *2, shall I change it to A1,A2 and C1,C2 to see if it makes a difference?


I have 16GBx2 and 8GBx2 - a total of 48GB... should be enough

thanks for any help

Regards

Russ