Ram Disks are limited to ~32GB size when TmpFS is used.

[tonmischa]

Trying to create a TmpFS RAM Disk with a size bigger than 32.768 results in a RAM Disk with 34,36 GB usable space.

(Maybe some Int16 limitation?)

[imothee]

Hmmm, turns out this is due to the way that mount_tmpfs works which seems to set a default limit to 50% of your total ram. I'll do some research to see if this can be changed, if not will have to set a max on creation I guess.

[tonmischa]

That explains it... I have 64 GB of RAM in my MacStudio.