I just bought a new iMac with 32g RAM, 3.6 GHz Intel Core i9,1TB hard drive running Mojave 10.14.6. I also use an Apollo 8P as my interface. Installed Pro Tools and finished a song. Went to start a new one with zero plug ins. System usage says I am using 100% of my RAM. I have changed the cache size as well as the h/w buffer to no avail. There is literally no way I am using all that RAM - nothing has been recorded or even playing! Anyone have any ideas?

Memory leak? Bad SIMM?

I mean, it is a brand new computer. I restarted pro tools last night - was at 0%, left the computer on - it is now at 40%.

Ooooo, I *do* love a good mystery!

Open the 'Activity Monitor' app in 'Utilities', and check the 2nd top tab for 'Memory'. There'll the first two columns displaying the 'Process Name' and 'Memory'. From that we can begin developing a list of suspects.

Keep in touch.

Pro Tools........ 3.1GB
AvidAppManHelper.......252.2MB
Activity Monitor ...... 102.7MB

I just recorded 4 guitar tracks, disk cache is at 78% and memory is at 48%. Zero plug ins.

Gearslutz is #4 with 90.3 mb

I am very quickly realizing that there may be a terminology problem that may send us all into the ditch.

- What product/component has the 'System Usage' indicator at 100% ?
- I assume that the "cache size" and "HW buffer" settings are within the Pro Tools product. True?

Since that Activity Monitor says Pro Tools is using 3.1GB of RAM, I'm guessing that the "System Usage" indicator is also a Pro Tools internal asset that's reporting. I stopped using Pro Tools long ago, so I'm not the right one to move this diagnosis forward.

Which version number of Pro Tools is in play? A 32-bit version perhaps?