Linux RAID mdraid "stripe_cache_size" vs. transfer rate

Part of the Linux RAID mdraid RAID6 & RAID5 benchmarks, and Linux RAID mdraid RAID10, RAID0 benchmarks (continued) series.

"stripe_cache_size" vs. transfer rate

Generated with the following shell script:

for cache_size in 256 512 768 1024 2048 4096 8192 16834 32768; do
 for i in {1..3}; do
 echo ${cache_size} > /sys/block/md0/md/stripe_cache_size
 echo 3 > /proc/sys/vm/drop_caches
 echo "stripe_cache_size: ${cache_size} (${i}/3)"
 # for write
 dd if=/dev/zero of=/dev/md0 bs=3145728 count=5460
 # for read
 dd if=/dev/md0 of=/dev/null bs=3145728 count=5460