Disk Cache oddity

[Frank Kruse]

I'm having weird things happening with disk cache. So I have 48GB of RAM. I assigned 16GB to disk cache. I currently have a massive session containing 20 episodes along the timeline to assemble a couple of new ones.

A bit extreme I know but there's no other way to do this efficiently.

PT throws up an error from time to time that I'm running low on RAM and that I should lower the disk cache to let it use more and then the confusing part of the message: "you currently have 16GB of unused space in disk cache"

When I look at the system usage I indeed see 9% of disk cache used. Why on earth are only 9% of 16GB used when I have 200 tracks of BG and FX track-lay for 20 45minute episodes of film in my session? That seems like a miracle to me. Or does PT only cache the surrounding of the current cursor position? I always thought it will try to fill the entire cache.

So I lower the disk cache down to 8GB just to see what happens. MacOS says I now have 32GB available memory total. Memory usage is down to 83% (it was at 99% before) but now disk cache is at 100%.

So before:


dc assigned: 16GB
dc used: 9%
system memory available: 10GB
PT usage window: Memory 99%

after switch to 8GB
dc assigned: 8GB
dc used: 100%
system memory available: 25GB
PT usage window: Memory 83%

So then I set DC back to 16GB. Now Memory in system usage is at 100%. MacOS says I have 32GB available and disk cache is at 0% and doesn't really re-cache after I hit play.

Very odd. What am I not getting? Seems very buggy to me.

Thanks!

Frank.