Linux tar –blocking-factor

I wasn’t aware of tar’s –blocking-factor parameter:

   -b, --blocking-factor=BLOCKS
          Set record size to BLOCKSx512 bytes.

This actually reduces CPU load and backup creation times measurably. Figures for backing up 7GB on my home NAS:

Setting Seconds

Setting		Minutes.Secods
------------------------------
default		1.18
 512		1.07
1024		1.05
2048		1.08

The fastest setting (1024) is 11% faster than the slowest (default).