Read timings on file systems

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Figured I would post this for information sharing purpose.

I have been doing some device read timings on internal memory / sdcard file systems.

My setup:

- internal flash -> standard
- SD card with 1 VFAT partition
- SD card with 1 ext4 partition

Below measured read timings (measured with "hdparm -t"):

1) internal flash

bash-3.2# /data/hdparm -t /dev/block/mmcblk0p25
/dev/block/mmcblk0p25:
Timing buffered disk reads: 90 MB in 3.01 seconds = 29.87 MB/sec

2) VFAT on sdcard partition

bash-3.2# /data/hdparm -t /dev/block/mmcblk1p1
/dev/block/mmcblk1p1:
Timing buffered disk reads: 22 MB in 3.07 seconds = 7.17 MB/sec

3) ext4 on sdcard partition

bash-3.2# /data/hdparm -t /dev/block/mmcblk1p2

/dev/block/mmcblk1p2:
Timing buffered disk reads: 28 MB in 3.03 seconds = 9.24 MB/sec

Clear where you have to store your data if you want high read throughput (and not surprising of course).

Note: "hdparm" compiled for arm from original source code.
Readahead = 8192 in all cases.