Robin Humble wrote: > On Thu, Jan 17, 2008 at 01:34:46PM +0300, Vladislav Bolkhovitin wrote: > >>Hmm, I can't find which IB hardware did he use and it's declared Gbps >>speed. He declared only "Mellanox 4X SDR, switch". What does it mean? > > > SDR is 10Gbit carrier, at most about ~900MB/s data rate. > DDR is 20Gbit carrier, at most about ~1400MB/s data rate.
Thanks. Then the single threaded rate with one outstanding command between SCST SRP on 8Gbps link vs STGT iSRP on 10Gbps link (according to that paper) is 600MB/s vs ~480MB/s (page 26). Still SCST based target is about 60% faster. > On Thu, 17 Jan 2008 10:27:08 +0100 "Bart Van Assche" <[EMAIL PROTECTED]> > wrote: > >>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 >> >> > > > it kinda looks to me like the tgt iSER tests were waaay too slow to be > using RDMA :-/ > I use tgt to get 500MB/s writes over iSER DDR IB to real files (not > ramdisk). Reads are a little slower, but that changes a bit with distro > vs. mainline kernels. _______________________________________________ Stgt-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/stgt-devel
