Ryousei, See my comments inlined. Thanks, Kashyap > -----Original Message----- > From: linux-scsi-owner@xxxxxxxxxxxxxxx [mailto:linux-scsi- > owner@xxxxxxxxxxxxxxx] On Behalf Of Ryousei Takano > Sent: Monday, November 30, 2009 7:38 PM > To: Desai, Kashyap > Cc: Moore, Eric; linux-scsi@xxxxxxxxxxxxxxx; DL-MPT Fusion Linux; Support, > Software; takano-ryousei@xxxxxxxxxx; Yang, Bo > Subject: Re: OCZ Z-drive p84 read performance > > Hi Kashyap, > > Thanks for your reply, and I am sorry for lack of information. > > I am using mpt fusion driver version 3.04.10. > > What setup information do you need? > > My PC consists of two Intel Quad-core Xeon E5430 2.66~GHz, Intel 5100 > chipset, > and 4 GB memory (DDR2-667). OCZ Z-Drive p84 is plugged into a > PCI-Express x8 lane. > > Here is my test script: > > #!/bin/bash > > BS=$((1024)) > COUNT=$((1024*1024*10)) > > for i in 1 4 16 64 256 512 1024 2048 4096 8192 16384 32768 65536; do > bs=$((BS * i)) > count=$((COUNT / i)) > > echo bs=$bs count=$count > sudo mount /dev/sdb1 /media/test > dd if=/dev/zero of=/media/test/foo bs=$bs count=$count > sudo umount /media/test > sleep 1 > sudo mount /dev/sdb1 /media/test > dd if=/media/test/foo of=/dev/null bs=$bs count=$count Replace /media/test/foo with /dev/sdb1, you will see raw read > rm /media/test/foo > sudo umount /media/test > done > This test is not purely RAW read/write test. In you test File system performance is also included. While read operation, (sequential read) File system buffering will give huge advantage to data transfer. > This script assumes the Z-drive is /dev/sdb1 and it is mounted on > /media/test. > > Best regards, > Ryousei > > On Mon, Nov 30, 2009 at 10:25 PM, Desai, Kashyap <Kashyap.Desai@xxxxxxx> > wrote: > > Ryousei, > > > > Replied inlined. > > > > Thanks, > > Kashyap > > > > > >> -----Original Message----- > >> From: Ryousei Takano [mailto:ryousei@xxxxxxxxx] > >> Sent: Monday, November 30, 2009 3:08 PM > >> To: Moore, Eric > >> Cc: linux-scsi@xxxxxxxxxxxxxxx; DL-MPT Fusion Linux; Support, Software; > >> takano-ryousei@xxxxxxxxxx > >> Subject: OCZ Z-drive p84 read performance > >> > >> Dear Eric Moore and all, > >> > >> I am installing ubuntu 9.10 (kernel 2.6.31-14-server) on my PC, which > >> has OCZ Z-Drive p84. > >> This drive consists of LSI logic's SAS1068E controller and 4 MLC SSDs. > >> I am using mptsas driver instead of the official binary driver > >> (megasar). > > Is this megaraid driver or mpt fusion? > > Driver version? > > > > I ran simple read & write > >> benchmark using dd(1). The result shows the throughput of sequential > >> read achieves 260 MB/s, > >> which is the half of sequential write performance (520 MB/s): > > Setup information? > >> > >> block size write (MB/s) read (MB/s) > >> 1024 201 241 > >> 4096 472 262 > >> 16384 486 267 > >> 65536 502 266 > >> 262144 472 259 > >> 524288 525 251 > >> 1048576 528 245 > >> 2097152 517 253 > >> 4194304 433 247 > >> 8388608 406 246 > >> 16777216 405 243 > >> 33554432 405 242 > >> 67108864 405 242 > >> > >> I wonder why read performance is worse than write performance. > >> What is the bottleneck of read performance? > >> > >> For more information, please see my page: > >> http://code.google.com/p/pspacer/wiki/ZdrivePerformance > >> > >> Any comments and suggestions will be welcome. > >> > >> Best regards, > >> Ryousei > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
