WD Passport Essential SE 1TB – Advanced format?

Having been using this WD Passport Essential SE 1TB USB removable drive (formatted as ext3) to backup my NAS for the last few months, I’ve been consistently underwhelmed by it’s performance. So I tried aligning the sectors to a 4kb boundary on the off chance it behaved like the WD10TPVT drives in use within the NAS itself, and I’m seeing write performance increases of such magnitude I’m left thinking the drive within (a WD10TMVV model) has 4kb physical sectors as well, Western Digitals so called ‘Advanced Format’.

A very simple benchmark of I/O write performance with non-4kb-aligned-sectors:

# fdisk -lu /dev/sds

Disk /dev/sds: 999.5 GB, 999501594624 bytes
255 heads, 63 sectors/track, 121515 cylinders, total 1952151552 sectors
Units = sectors of 1 * 512 = 512 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sds1   *          63  1952138474   976069206   83  Linux

# time dd if=/dev/zero of=zero count=1000 bs=1M
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 65.5702 s, 16.0 MB/s

real    1m5.869s
user    0m0.015s
sys     0m8.167s

And again with 4kb-aligned-sectors:

# fdisk -lu /dev/sds

Disk /dev/sds: 999.5 GB, 999501594624 bytes
255 heads, 63 sectors/track, 121515 cylinders, total 1952151552 sectors
Units = sectors of 1 * 512 = 512 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sds1   *           8  1952151551   976075772   83  Linux

# time dd if=/dev/zero of=./zero count=1000 bs=1M
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 36.2553 s, 28.9 MB/s

real    0m36.577s
user    0m0.009s
sys     0m7.906s

A near 100% improvement in write performance!