Hello, I recently purchased three net6501-70. I intend to use them with a pair of SATA disks each, mostly just for booting but I have to consider OS updates and unplanned usage patterns too. Everything was going fairly well but then I noticed I could get 90MB/sec read performance from my 2.5" hard drives and only about 20MB/sec write, even to the raw disk device with dd. If I put the drives in a normal desktop, write speed is fine. I've tried 2 other 2.5" SATA HD models and even a SSD. The SSD got 130MB/sec read but only 20MB/sec write. Even more mysterious is if I try to write to both disks at once, the 20MB/sec gets cut in half and each disk only does 10MB/sec. My symptoms sound similar to: http://lists.soekris.com/pipermail/soekris-tech/2012-June/018472.html
I was able to boot Ubuntu 12.10 and write over 80MB/sec using dd, an amount large enough that I know it is not being cached in ram. I noticed in Linux it appears to be using MSI for AHCI interrupts, but FreeBSD is not (it would by default if it detected MSI). I've already contacted the AHCI driver author in FreeBSD and he can't explain what might be happening without the hardware to experiment with. FreeBSD *does* use MSI for the Intel network ports. Has anyone been able to write to a SATA device using a net6501 running FreeBSD at over 20MB/sec? gstat -I 50000 is an easy command to watch the transfer speed. I am really hoping to find some way to improve this. I would be happy to provide more information or run reasonable tests. Thanks. _______________________________________________ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
