Do the M1 Macs “shutoff” RAM or CPU Cores

m1memory

Question

Is there any new way the M1 Macs manage memory or long running processes that would explain the behavior I describe below? I wanted to investigate what I might not know about the M1s before chalking it up to a software bug.

Background

When I run BOINC (via Rosetta2) it runs without issue with one project per CPU core. But after some time of inactivity it seems that certain cores are "shutdown". I have observed this happening one core (bionic task) at a time with about 30secs between the next "shutdown". The BOINC software seems to interpret this as the system not having enough memory. As can be seen in the image each project needs <1GB of RAM to run. With the Mac having 16gb of RAM all tasks can run.

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TLDR

M1 MacBook Air with 16gb seems to "shutdown" cores or parts of RAM after a predictable amount of time of inactivity.

Post Script

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Best Answer

No, the issue you're seeing is not in any way caused by the M1 "turning off memory" or "turning off cores". It is entirely caused by the manner in which this particular software program is structured.

Remember to check your BOINC settings - you can actually decide how large a part of your RAM that BOINC can use. The lower you set it (all else being equal), the more you'll see "Waiting for memory".