Date: Tue, 10 Apr 2007 12:37:21 +0800 From: "Tzu-Hua Wang" <biogary@gmail.com> To: freebsd-hardware@freebsd.org Subject: the performance of SAS is not better than SCSI in FreeBSD, WHY? Message-ID: <224a745a0704092137h67f5f463w6b355535a6b8415f@mail.gmail.com>
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Dear All:
I have bought the HP ProLiant DL380 G5 (SAS HD and RAID Controller)
By using "diskinfo -t", the information of HD performace is:
=========================================================
/dev/da1
512 # sectorsize
146778685440 # mediasize in bytes (137G)
286677120 # mediasize in sectors
35132 # Cylinders according to firmware.
255 # Heads according to firmware.
32 # Sectors according to firmware.
Seek times:
Full stroke: 250 iter in 2.578974 sec = 10.316 msec
Half stroke: 250 iter in 2.099233 sec = 8.397 msec
Quarter stroke: 500 iter in 2.277551 sec = 4.555 msec
Short forward: 400 iter in 2.018527 sec = 5.046 msec
Short backward: 400 iter in 2.636941 sec = 6.592 msec
Seq outer: 2048 iter in 2.052169 sec = 1.002 msec
Seq inner: 2048 iter in 2.052077 sec = 1.002 msec
Transfer rates:
outside: 102400 kbytes in 2.547162 sec = 40202 kbytes/sec
middle: 102400 kbytes in 3.151423 sec = 32493 kbytes/sec
inside: 102400 kbytes in 3.342559 sec = 30635 kbytes/sec
=========================================================
I have an old server, only SCSI HD and RAID Controller.
By using "diskinfo -t", the information of HD performace is:
=========================================================
/dev/da0
512 # sectorsize
73543163904 # mediasize in bytes (68G)
143638992 # mediasize in sectors
8941 # Cylinders according to firmware.
255 # Heads according to firmware.
63 # Sectors according to firmware.
Seek times:
Full stroke: 250 iter in 2.968575 sec = 11.874 msec
Half stroke: 250 iter in 2.218879 sec = 8.876 msec
Quarter stroke: 500 iter in 3.569766 sec = 7.140 msec
Short forward: 400 iter in 1.798317 sec = 4.496 msec
Short backward: 400 iter in 1.872876 sec = 4.682 msec
Seq outer: 2048 iter in 0.258105 sec = 0.126 msec
Seq inner: 2048 iter in 0.458751 sec = 0.224 msec
Transfer rates:
outside: 102400 kbytes in 1.181019 sec = 86705 kbytes/sec
middle: 102400 kbytes in 1.405735 sec = 72844 kbytes/sec
inside: 102400 kbytes in 2.100786 sec = 48744 kbytes/sec
==========================================================
Generally, the performace of SAS in FreeBSD is far worse than SCSI in FreeBSD.
Is it normal? How can I do to improve the performance of SAS HD in FreeBSD?
Thank you
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