I am having an issue with ram usage so I tried to turn off caching on the DOP network. Technically I'm just writing the cache to disk I don't really need it stored in memory, but this became a problem because the sim behavior changes. Then I read a little more and found this.

http://www.sidefx.com/docs/houdini/nodes/obj/dopnet.html [www.sidefx.com]
“Many solvers will not work properly unless this option is enabled”

Anyone know more specifically what options don't work properly? I need to weigh the options of using vs not using this caching option, because for some reason my machine keeps crashing beccause it is out of ram, but if I turn it off, the sim will finish but it looks different, I don't want to be in the wild west of unreliability and need more info about what works and what doesn't with caching disabled?

You can limit the Cache Memory to something like 1000-2000 MB on the DOP network since outright disabling caching are not advisable from my experience.

Hopefully others can chip in their advice on this issue.

What I don't understand is when I set a memory limit, why doesn't the machine respect that limit and just swap the ram when it needs more. The machine seems to just plow through and use 64 GB of ram, and then crash.

I'm not sure if that's an issue with the machine or with the settings in Houdini to run the sim?

So lowering the cache limit seemed to help prevent the machines from maxing their ram and crashing.

But what I don't understand is this “Cache Memory (MB)” setting doesn't seem to work as expected?

You would expect the machine to start swaping the ram when it reaches the limit but its not happening. For example when the default of 5000 MB is used the machines will peak at over 20,000 MB usage during the caching process, so It's not clear if this is a multiplier per frame or per CPU thread? Would be helpful to know so I can more accurately allocate the ram usage per sim.