Hi
Ubuntu 20.04 aarch64, Open-MPI 4.0.3, HPL 2.3
Having changed the MTU across my small cluster from 1500 to 9000, I’m wondering
how/if Open-MPI can take advantage of this increased maximum packet size.
ip link show eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc mq state UP mode
DEFAULT group default qlen 1000
link/ether dc:a6:32:60:7b:cd brd ff:ff:ff:ff:ff:ff
Having run a Linpack benchmark before and after the MTU change, it appears to
have had minimal impact on performance. I was, probably naively, expecting some
benchmark improvement. Are there any Open-MPI parameters, or compiler options,
that can tweaked that are related to MTU size?
Kind regards
