USB drives connected to the rev2 running Raspbmc read/write twice as quickly as the rev1 running Raspbian. Why is there a difference in speed?
I tested the same external USB hard drive connected to both machines. I created a 50 MB test file from random data.
$ dd if=/dev/urandom of=/media/HDD/randomness bs=1M count=50
On the Raspbmc (two replicates):
$ time cp randomness randomness2 real 0m1.922s real 0m1.984s
On the Raspbian (two replicates):
$ time cp randomness randomness2 real 0m4.649s real 0m4.709s
I compared the mount options. On the Raspbmc
$ mount | grep media /dev/sda1 on /media/HDD type ext4 (rw,nosuid,nodev,uhelper=udisks)
On the Raspbian (mounted with
$ mount | grep media /dev/sdb1 on /media/HDD type ext4 (rw,noatime,data=ordered)
I tested mounting the Raspbian HDD with
noatime,nosuid,nodev,data=writeback, but I still get read/write times that are about double that of the Raspbmc
real 0m5.127s real 0m4.966s
Why is the rev1 Raspbian Pi hard drive not as quick as the rev2 Raspbmc?