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
