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kirkbross

macrumors 6502a
Original poster
Mar 6, 2007
666
22
Los Angeles
I have the latest Mac Mini with 32GB of memory. How can it be that with only Activity Monitor open, it shows 10GB used (7GB apps / 3GB wired)?

Please help me understand why this is normal.
 

LogicalVue

macrumors regular
Aug 28, 2007
103
86
USA (Maine)
It's normal because unused RAM is wasted RAM. Generally macOS tries to keep RAM highly utilized. Things will be cleared out when needed. As long as your Memory Pressure graph remains in the green, you are fine and don't need to worry about the Used amount.
 

macdos

Suspended
Oct 15, 2017
604
969
That is so not true. It will keep cached files as long as it can, preferring to swap to disk and compress memory before giving up cache, slowing down the system considerably. Doesn't happen on Linux.

My Windowserver is currently 14 GB, and it can't be purged. Real memory is 1.2 GB.

It's normal because unused RAM is wasted RAM. Generally macOS tries to keep RAM highly utilized. Things will be cleared out when needed. As long as your Memory Pressure graph remains in the green, you are fine and don't need to worry about the Used amount.
 

Krevnik

macrumors 601
Sep 8, 2003
4,100
1,309
That is so not true. It will keep cached files as long as it can, preferring to swap to disk and compress memory before giving up cache, slowing down the system considerably. Doesn't happen on Linux.

This seems to run counter to the whole design of the memory manager in the OS. But it should be noted that VM used isn’t the same as pages resident in RAM. So untangling what is going on in memory isn’t straight-forward.

It’s hard to really help provide clarity in the general case, but I can say this isn’t the sort of behavior I’ve seen as a developer.

My Windowserver is currently 14 GB, and it can't be purged. Real memory is 1.2 GB.

Its very likely there’s a lot of memory mapped or shared data in there causing the VM address space to have a lot of usage. Real memory is the count of allocated pages associated with the process. Real memory is the one you should pay closer attention to if RAM usage if what you want to know about.

There isn’t really any point to purging a VM page that hasn’t even been faulted in yet, and made real. If it hasn’t been faulted in, there is no RAM being used at that point.

Although having that much virtual memory addressable is pretty large. Now I’m curious about how Windowserver moves data between processes, as I suspect it’s related to that.
 
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