RAID Setup WC OFF

RAID Controller: 3ware 9650SE
RAID Level: RAID10 256K
Disks: 4 x Western Digital RE4 2000 GB
Write Cache Setting: Disabled
Read Cache Setting: Intelligent
Drive Queuing Mode: Enabled
StorSave Profile: Balanced

RAID Performance WC OFF

dd if=/dev/sda of=/dev/null bs=1M count=16000
16777216000 bytes (17 GB) copied, 56.0381 s, 299 MB/s

lvcreate data-fast -n test -L 32g
dd if=/dev/zero of=/dev/data-fast/test bs=1M count=16000
16777216000 bytes (17 GB) copied, 79.4135 s, 211 MB/s

mkfs.ext3 -b 4096 -E stride=64 -E stripe-width=128 /dev/data-fast/test
mount -o noatime /dev/data-fast/test /mnt
bonnie++ -d /mnt -u root -n 0
Version  1.96       ------Sequential Output------ --Sequential Input- --Random-
Concurrency   1     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
finnix          12G   563  99 153523 26 84247  13  2049  99 292174 21 597.8  13

cat /sys/block/sdb/queue/scheduler
noop anticipatory deadline [cfq]
cat /sys/block/sdb/device/queue_depth
254
cd /tmp; http_proxy=http://proxy.gsd-software.net:8080 wget http://smp.if.uj.edu.pl/~baryluk/seeker_baryluk; chmod +x seeker_baryluk
for threads in 01 02 04 08 16 32; do echo -n "Threads: $threads "; ./seeker_baryluk /dev/sdb $threads | grep Results; sleep 1; done
Threads: 01 Results: 84 seeks/second, 11.895 ms random access time (974994305 < offsets < 3994280682071)
Threads: 02 Results: 166 seeks/second, 6.005 ms random access time (1655876718 < offsets < 3999256645656)
Threads: 04 Results: 259 seeks/second, 3.854 ms random access time (761879086 < offsets < 3998661172497)
Threads: 08 Results: 333 seeks/second, 3.002 ms random access time (312727063 < offsets < 3999696575773)
Threads: 16 Results: 382 seeks/second, 2.613 ms random access time (19132984 < offsets < 3999676178060)
Threads: 32 Results: 412 seeks/second, 2.422 ms random access time (434897278 < offsets < 3999690548287)

RAID Setup WC ON

RAID Controller: 3ware 9650SE
RAID Level: RAID10 256K
Disks: 4 x Western Digital RE4 2000 GB
Write Cache Setting: Enabled
Read Cache Setting: Intelligent
Drive Queuing Mode: Enabled
StorSave Profile: Balanced

RAID Performance WC ON

dd if=/dev/sdb of=/dev/null bs=1M count=16000
16777216000 bytes (17 GB) copied, 55.9486 s, 300 MB/s

dd if=/dev/zero of=/dev/data-fast/test bs=1M count=16000
16777216000 bytes (17 GB) copied, 59.1244 s, 284 MB/s

mkfs.ext3 -b 4096 -E stride=64 -E stripe-width=128 /dev/data-fast/test
mount -o noatime /dev/data-fast/test /mnt
bonnie++ -d /mnt -u root -n 0
Version  1.96       ------Sequential Output------ --Sequential Input- --Random-
Concurrency   1     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
finnix          12G   585  99 181292 32 108096 17  1975  93 275122  19 608.8  14