Hi all. For now just posting to -performance and -questions. Please advise if e.g. -hardware is more suitable.
I first reported this issue on forum: https://forums.freebsd.org/threads/mrsas-and-the-mystery-of-lost-speed.79585/ which will offer you detailed report. Here're cliffnotes: Dell R730 + PERC H730 (LSI SAS3108 controller) + SAS-3 12Gbps SSD drives. With `mrsas` driver I'm getting transfers reported 150MB/s which is obviously nonsense (best guess is mrsas thinks its talking SAS-1 at 1Gbps) and indeed random IO tested with `fio` on FreeBSD and on Linux show 2x perf difference. Above Forum post links respective spec-sheets etc. Was also advised that something similar had been reported for another LSI 3108 controller https://forums.freebsd.org/threads/system-hang-freezing-boot-lsi-3108-and-seagate-exos-7e8.76373/ but was solved by replacing controller with another model. I'm also seeing a separate issue where for whatever reason PERC controller BIOS reports negotiated speed for the drives at 6Gbps - but that's probably some HW issue. Trying to figure this with Dell community support, my seller and anyone who would listen really. Thank you -- Best regards Vlad Kozin _______________________________________________ freebsd-performance@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to "freebsd-performance-unsubscr...@freebsd.org"
