I’m running make.contigs on my local desktop (Mac Pro with 32G RAM). It always fails in the middle. But the job can be finished in my M1 Mac Air with 8G RAM. I found the memory usage is very different. When it runs on M1 Mac Air, the memory usage is about 400~500 MB. But in my Mac Pro (3.5 GHz 8-Core Intel Xeon W), it uses 200GB (most in SWAP) and was killed with error “Killed:9”. The version of mothur is 1.44.11 on both machine.
I’m not sure why there’d be a difference between the two computers. How many processors does the MacPro have? I wonder if the Pro’s using a lot more processors than the Air and thus sucking up more RAM per processor. Also, you might try upgrading mothur to 1.45.3, which is the current release.