Hi all
Here’s a default cold smoke setup on a 1cm sphere.
iMac Pro sim is pretty quick.
Mac Pro sim is very slow.
Same default scenes.
Scenes on desktop not server.
iMac Pro - 10 core, 128GB RAM
Mac Pro - 28 core, 192GB RAM
Can I send the movies to a DM please as they’re too big and .mp4 which won’t upload.
Cheers
Steve
Hello,
You can send file over through https://support.chaos.com/hc/en-us - there is a submit a request button at the top right.
Can you also set the log verbosity to debug, run the sims again for a few frames and send over the log files if possible. This would provide us with more info on what is happening. You can do that from the the Global Preferences window from the top Maya PhoenixFD menu.
Usually the log is located in** /Users/$USERNAME/**
Thanks a lot!
Hi Georgi
Thanks for the info.
I’ve posted the vids and the log fro the macPro.
Will get the iMac Pro log sorted too and send over.
Cheers
Thanks a lot for the logs, we have a suspicion that it might be that the more threads are causing the issue.
Can you try to go to the Simulation rollout of the simulator > Threading > and change the thread limit to something like 10 or 20 for example. Does this speed up the process on the slower machine?
Ah, the threads appear to have an effect on the speed:
On 10 Threads
Faster and more like the PC and imacPro
2x Maya crashes so far
On 20 Threads
Faster also
Maya crashed on frame 36 with message
‘Copy the existing caches of ‘PhoenixSimulator1’ to the new location?’
56 Threads
Back to slow sim
28 Threads
Crashed at frame 37.5
Oh, nice!
If there is a dump file - can you send it over?
The crash dump files are stored either in the /Library/Logs/DiagnosticReports (system-wide) or ~/Library/Logs/DiagnosticsReports (user-wide) directories, depending on the type of the process that has led to the crash.
Another crash dump file named core.<pid> (where <pid> stands for the PID of the crashed process) must be created in the /cores directory. In order to create this second crash dump file, activate the full core dumps via the ulimit -c unlimited command which makes the core dump files size unlimited. Also make sure to have write permissions for the /cores directory.
In case the /cores directory is hidden in Finder, you can show the hidden files via the defaults write com.apple.finder AppleShowAllFiles TRUE command.
Thanks a lot for the help!
Thanks for the info.
Does the crash dump file have the .hang file extension?
I may need a bit more info on how to get the core. file.
A dummies guid really 
Funnily enough, I haven’t had more crashes on simming since our last email
Just a query on speed, will the ‘use GPU to aid simulation’ help the speed on the Mac?
The Mac Pros have AMD Radeon PRO W6800X 32 GB
Cheers again
Sweet spot seems to be 10 Threads.
Weird how 12 Threads is double the time and then 20 Threads is a bit quicker.
5 Threads 1min
10 Threads 33sec
12 Threads 1min 1
20 Threads 45sec
10 Threads
Deselecting ‘Use GPU ro Aid Simulation’ seems to be roughly the same - 32.8 sec
Interestingly if we drag out a Simulator from scratch (not a preset), and add a Source and then ball, the speeds seems to be ok with Threads on 0.
Correction - putting the Threads on 10 speeds the sim up even more.
Could there be an issue with some of the presets?
If you use the same settings as the preset when building a sim from scratch and there is a difference - this means there is an issue indeed.
If you compare the speed between a default simulator and a default Source to one of the presets - there will a significant difference due to the many settings affecting the sim.
As for the dump files - you can press Command + Shift + . to show hidden items on Mac
Cool, cheers for the info.
Just had a crash but nothing appeared in the cores folder.
On the default sim and source file:
I turn off the Temperature and put the adaptive grid on Smoke but the grid doesn’t become adaptive.
The adaptive grid works ok with temperature on and set to Temperature/liquid?
When you use the Smoke for the adaptivity - you will need to adjust the threshold to be something like 0.01 for example, the Threshold for the Temperature that is used by default is 1000 and is too high for the smoke.
Super, cheers for the info.
Do you think that the thread issue is a bug?
Would be nice to use all 56 Threads instead of 10 for sims.
It’s not a bug - when it comes to fluid simulations - processor speed is more important than core count.
NUMA and multiprocessor architectures do not perform well with Phoenix. Simulating on one NUMA node or on limited number of threads is often faster than waiting for multiple nodes to synchronize.
I hope things can be improved in the future, but it’s a difficult task to handle so let’s see how things go.
Cool, thanks for the info.
It’s weird how the speed changes across cores though.
5 - slow
10 - faster
12 - a lot slower
20 - faster the 12 etc.
And adding GPU was a little slower.
__________________________________________________ __________________________________________________
5 Threads 1min
10 Threads 33sec
12 Threads 1min 1
20 Threads 45sec
__________________________________________________ __________________________________________________
Just want to mention that several artists here had decided that Phoenix was not usable as the sim speed was too slow.
It’s pretty important to cover that there seems to be a magic 10 thread (or perhaps 1 thread) somewhere in the manual, where a dead slow sim then becomes somewhat usable.
I’ve only stumbled across this through persistence as I wanted to keep within the Chaos render family/ecosystem.
Just want to mention that several artists here had decided that Phoenix was not usable as the sim speed was too slow.
It’s pretty important to cover that there seems to be a magic 10 thread (or perhaps 1 thread) somewhere in the manual, where a dead slow sim then becomes somewhat usable.
I’ve only stumbled across this through persistence as I wanted to keep within the Chaos render family/ecosystem.
It’s pretty important as some people will just assume that phoenix is too slow and move on to Houdini etc.
