[OpenIndiana-discuss] Test on Sun X4170M2 between STEC Mach16 SLC/MLC and Intel DC S3700

[Albert Chin]

I've tested three SSDs in a Sun X4170M2. This server has 8 internal
SSD 2.5" drive bays with a Sun Storage 6 Gb SAS PCIe RAID HBA. I
believe the chipset on the HBA is a LSI SAS2108 (according to
http://tinyurl.com/koc6kdn).

I tested by adding each SSD as a ZIL for a pool and then running the
following command on one of the file systems in the pool:
  $ /usr/gnu/bin/dd if=/dev/zero of=file bs=1 oflag=sync

Iostat numbers below are given by:
  $ iostat -cnx 1

$ cat /kernel/drv/sd.conf
...
sd-config-list="*MACH16*","disksort:false, cache-nonvolatile:true",
               "*INTELSSD*","disksort:false, cache-nonvolatile:true, physical-block-size:8192";

The 8k block size for the Intel S3700 comes from:
  http://wiki.illumos.org/display/illumos/List+of+sd-config-list+entries+for+Advanced-Format+drives

Product part numbers:
  1. STEC Mach16 SLC 100GB - M16CSD2-100UIU
  2. STEC Mach16 MLC 200GB - M16ISD2-200UCV
  3. Intel DC S3700 - SSDSC2BA200G301

ATA-STEC    MACH16 M-0300-93.16GB (SLC)
  $ /usr/gnu/bin/dd if=/dev/zero of=file bs=1 oflag=sync
  $ iostat -cnx 1
  r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b
  0.0 1439.2    0.0 5756.9  0.0  0.8    0.0    0.6   0  84
  0.0 1478.7    0.0 5915.0  0.0  0.9    0.0    0.6   1  86
  0.0 1491.1    0.0 5964.2  0.0  0.9    0.0    0.6   1  88
  0.0 1506.0    0.0 6023.8  0.0  0.9    0.0    0.6   0  89

ATA-STEC    MACH16 M-0289-186.31GB (MLC)
  $ /usr/gnu/bin/dd if=/dev/zero of=file bs=1 oflag=sync
  $ iostat -cnx 1
  r/s    w/s   kr/s    kw/s wait actv wsvc_t asvc_t  %w  %b
  0.0 8079.7    0.0 32318.9  0.0  0.5    0.0    0.1   2  52
  0.0 8229.1    0.0 32916.5  0.0  0.5    0.0    0.1   2  53
  0.0 7368.0    0.0 29471.9  0.0  0.5    0.0    0.1   2  47
  0.0 7318.0    0.0 29272.2  0.0  0.5    0.0    0.1   2  47

ATA-INTEL SSDSC2BA20-0270-186.31GB (MLC)
  $ /usr/gnu/bin/dd if=/dev/zero of=file bs=1 oflag=sync
  $ iostat -cnx 1
  r/s    w/s   kr/s    kw/s wait actv wsvc_t asvc_t  %w  %b
  0.0 9196.0    0.0 18392.0  0.0  0.2    0.0    0.0   1  19
  0.0 9144.3    0.0 18288.6  0.0  0.2    0.0    0.0   1  19
  0.0 9288.7    0.0 18575.5  0.0  0.2    0.0    0.0   1  19
  0.0 8352.0    0.0 16704.0  0.0  0.2    0.0    0.0   1  17

The STEC Mach16's are 3.0Gbps devices. The Intel SSD DC S3700 is a
6.0Gbps device. Just two questions:
  1. Why don't I see double the IOPS performance between the
     6.0Gbps device than the 3.0Gbps devices?
  2. Why does the STEC Mach16 100GB SLC suck so badly in comparison
     to it's 200GB MLC cousin? I know that the 100GB drives won't
     perform as well as the 200GB models but I did not expect this
     much of a difference.

Even using bs=4096 on the Intel S3700, I was hoping to see >10K IOPS,
possibly matching the numbers from the anandtech review:
  http://www.anandtech.com/show/6433/intel-ssd-dc-s3700-200gb-review/3
ATA-INTEL SSDSC2BA20-0270-186.31GB (MLC)
  $ /usr/gnu/bin/dd if=/dev/zero of=file bs=4096 oflag=sync
  $ iostat -cnx 1
  r/s    w/s   kr/s    kw/s wait actv wsvc_t asvc_t  %w  %b
  0.0 8714.5    0.0 34858.0  0.0  0.2    0.0    0.0   1  22
  0.0 8410.9    0.0 33639.6  0.0  0.2    0.0    0.0   1  21
  0.0 8431.1    0.0 33728.2  0.0  0.2    0.0    0.0   1  21
  0.0 8295.0    0.0 33224.0  0.0  0.2    0.0    0.0   1  21
  0.0 8970.1    0.0 35740.4  0.0  0.2    0.0    0.0   1  23

Am I getting the best possible performance out of the Intel S3700?

-- 
albert chin (china at thewrittenword.com)