[slack3r]

You're only reading 300MB, which is being cached in available memory on the Pi2, so after the first read from SD card the second read is simply reading from the RAM cache. That's why my test is using count=1000 so there's no risk of the entire file being cached.

Ok, thanks.

[EDIT]
New test on Pi 2:

Code:

~ # dd if=/dev/mmcblk0p2 of=/dev/null count=1000 bs=1M
1000+0 records in
1000+0 records out
1048576000 bytes (1000.0MB) copied, 33.034641 seconds, 30.3MB/s

~ # dd if=/dev/mmcblk0p2 of=/dev/null count=1000 bs=1M
1000+0 records in
1000+0 records out
1048576000 bytes (1000.0MB) copied, 33.029086 seconds, 30.3MB/s

and Pi 1B:

Code:

~$ sudo dd if=/dev/mmcblk0p2 of=/dev/null count=1000 bs=1M
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 57.0789 s, 18.4 MB/s

~$ sudo dd if=/dev/mmcblk0p2 of=/dev/null count=1000 bs=1M
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 57.0655 s, 18.4 MB/s

Sounds good?