Slow transfer rate on my ext2 partition (Ubuntu 10.04 64 bit)

[stefanofalone]

Hi everyone,
I would like to know if it is normal to experience 10MB/s data transfer rates during copying between partitions on my local hard drives (Toshiba 250GB 5400rpm SATA) while having three times faster (30MB/s) transfer rates between local partitions and USB drives (Kingston 8GB).

Thank You all very much in advance.

Stefano

[Bemk]

Hi everyone,
I would like to know if it is normal to experience 10MB/s data transfer rates during copying between partitions on my local hard drives (Toshiba 250GB 5400rpm SATA) while having three times faster (30MB/s) transfer rates between local partitions and USB drives (Kingston 8GB).

Thank You all very much in advance.

Stefano

Needle movement could be the issue. When copying from partition to partition reading and writing must be interrupted to do each other and in the mean time the needle needs to move to the right place, while when copying from disk to another disk, both actions can be done at the same time letting the needles stay more or less in the same place.
I already notice when copying from 1 place on the partition to another in the same (shorter movements than in partition1 to partition 2).

[Rubberman]

Drive performance depends upon a number of things, such as how the drive is mounted (sync vs async), how much memory the system has for caching data, etc. Also, remember that copying between partitions on the same disc will saturate the sata bus and cause a lot of head thrashing because you are reading/writing from/to different parts of the same drive. The last item can be ameliorated somewhat by use of the appropriate software for copying. Tools like rsync or dd will do a better job at that than cp, cat, etc. because they have options for specifying how much data to read before writing, resulting in fewer head seeks and read/write operations.