Date: Wed, 14 Mar 2007 15:09:28 +1100 From: Andrew Reilly <andrew-freebsd@areilly.bpc-users.org> To: freebsd-questions@freebsd.org Subject: Expected speed of firewire-attached drive? Message-ID: <20070314150928.2004950b@duncan.reilly.home>
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Hi there, I don't do a whole lot of benchmarking: mostly my computer's speed is "perfectly adequate", and working reliably is key. At the moment, though, I'm curious. I'm sitting here while I attempt to restore a file from a level-0 dump, and it's taking a while. The backup medium is one of those firewire-attached Maxtor 300G drives, but to make it interesting I compress the backup image with bzip2 (which keeps the file size down to about 16G). Dmesg.boot says that the drive is capable of 50MB/s, the firewire driver says nothing obvious about speed, except "invalid speed 7 (fixed to 3)." (details below). The motherboard is a relatively shiny Athlon X2-4400 NVidia-4 based system, so there ought to be oodles of compute grunt for this exercise, surely? Anyway, systat -vmstat says that da0 is doing about 40 128KB transfers per second, or about 5MB/s (actually a bit under), or 12% busy. One of the CPUs is pegged. Hmm, it's pegged running bzcat. That would be the bottleneck, then. OK, so I've answered my own question. Please consider this post informative or noise at your discretion: I'm going to post it anyway on the grounds that it might provoke some interesting discussion, and perhaps a suggestion for a less cpu-hungry compression algorithm (I guess I could try gzip for the next backup...) Cheers, from dmesg.boot: fwohci0: <Texas Instruments TSB82AA2> mem 0xf0004000-0xf00047ff,0xf0000000-0xf00 03fff irq 18 at device 10.0 on pci1 fwohci0: OHCI version 1.10 (ROM=1) fwohci0: No. of Isochronous channels is 4. fwohci0: EUI64 00:14:85:56:00:e6:80:b0 fwohci0: invalid speed 7 (fixed to 3). fwohci0: Phy 1394a available S800, 3 ports. fwohci0: Link S800, max_rec 4096 bytes. firewire0: <IEEE1394(FireWire) bus> on fwohci0 fwe0: <Ethernet over FireWire> on firewire0 if_fwe0: Fake Ethernet address: 02:14:85:e6:80:b0 fwe0: Ethernet address: 02:14:85:e6:80:b0 fwe0: if_start running deferred for Giant sbp0: <SBP-2/SCSI over FireWire> on firewire0 fwohci0: Initiate bus reset fwohci0: node_id=0xc800ffc1, gen=1, CYCLEMASTER mode firewire0: 2 nodes, maxhop <= 1, cable IRM = 1 (me) firewire0: bus manager 1 (me) fwohci0: phy int ... da0 at sbp0 bus 0 target 0 lun 0 da0: <Maxtor OneTouch II 0310> Fixed Direct Access SCSI-4 device da0: 50.000MB/s transfers da0: 286188MB (586114704 512 byte sectors: 255H 63S/T 36483C) -- Andrew
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