[mhb]

I had Activity Monitor running and it was showing "inactive memory" at about 25% of RAM.

Then I kicked off OmniDiskSweeper and after a few seconds, the "inactive memory" became "free".

I am curious what OmniDiskSweeper does to do this? The only way I have seen this happen before is after a restart.

Thanks
Mark

[Brian]

Did the number get larger or smaller?

Inactive memory is memory that's sitting there idle. By firing up OmniDiskSweeper, more memory would be put into use, which I would expect would make the inactive memory number shrink. (By using up some of that free memory.)

[mhb]

Overall, the free memory slice increased and the inactive memory slice decreased.

And this is "Free" and "Inactive" as shown in Activity Monitor on the System Memory tab.

Interestingly, the same behaviour also happens when running SuperDuper!

Cheers
Mark