[Stgt-devel] Performance of SCST versus STGT
Thu Jan 17 10:40:52 CET 2008
On Thu, 17 Jan 2008 10:27:08 +0100
"Bart Van Assche" <bart.vanassche at gmail.com> wrote:
> I have performed a test to compare the performance of SCST and STGT.
> Apparently the SCST target implementation performed far better than
> the STGT target implementation. This makes me wonder whether this is
> due to the design of SCST or whether STGT's performance can be
> improved to the level of SCST ?
> Test performed: read 2 GB of data in blocks of 1 MB from a target (hot
> cache -- no disk reads were performed, all reads were from the cache).
> Test command: time dd if=/dev/sde of=/dev/null bs=1M count=2000
> STGT read SCST read
> performance (MB/s) performance (MB/s)
> Ethernet (1 Gb/s network) 77 89
> IPoIB (8 Gb/s network) 82 229
> SRP (8 Gb/s network) N/A 600
> iSER (8 Gb/s network) 80 N/A
> These results show that SCST uses the InfiniBand network very well
> (effectivity of about 88% via SRP), but that the current STGT version
> is unable to transfer data faster than 82 MB/s. Does this mean that
> there is a severe bottleneck present in the current STGT
> implementation ?
I don't know about the details but Pete said that he can achieve more
than 900MB/s read performance with tgt iSER target using ramdisk.
http://www.mail-archive.com/stgt-devel at lists.berlios.de/msg00004.html
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