On Fri, 31 Aug 2007 12:50:42 -0500
Les Mikesell <lesmikesell(a)gmail.com> wrote:
Mikkel L. Ellertson wrote:
> dd should not use lots of CPU time. The bottleneck is disk access
> speed. Depending on the drivers used, and some tweaking, the system
> may be spending a lot of time in the disk driver routines doing
> basically nothing.
CPU use will depend on your disk controller. IDE controllers have a lot
of CPU overhead for seeks/positioning even if DMA is used for the data
transfer - that's why people still use SCSI for busy servers.
Thankfully no longer true as of SATA providing your controller does AHCI
or similar and the drives support NCQ
Alan