[issue1116] HAMMER:file read speed

Matthew Dillon dillon at apollo.backplane.com
Mon Aug 11 19:53:38 PDT 2008

    The two configurations aren't even remotely similar.

    You are comparing a FreeBSD SMP system running on 2 cpus against
    a DragonFly kernel running on 1.

    The VMWare running FreeBSD is emulating an Intel ethernet adapter (EM0).
    The one running DragonFly is emulating LNC0.  Totally different network
    adapters.  EM0 is a much better adapter.

    The disk configuration is also completely different.  If those VMWare
    disks are backed by plain files they could be fragmented on top of that.

    If you want to compare the systems you need to equalize the
    configurations so you are comparing the same thing.  FreeBSD
    will still probably pipe the dd test better, but it won't be 2x.

    My guess is that the network adapter differences are creating the
    biggest issue.  Get EM running on DragonFly too, instead of LNC.  Also
    either run FreeBSD UP or build a SMP DragonFly kernel.  Check the
    VMWare setup for those disks as well.


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