I traced down the poor performance I was seeing with USB to only the ext2 filesystem. With FAT32 I am getting 10MB/sec for file transfers, but with ext2 I am only getting 100KB/sec.
I formatted the drive with:
mkfs.ext3 -j -L iomega -O dir_index,has_journal,large_file -t ext3 -v /dev/sdc1
mke2fs 1.41.11 (14-Mar-2010) fs_types for mke2fs.conf resolution: 'ext3', 'default' Calling BLKDISCARD from 0 to 1014095872 failed. Filesystem label=iomega OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 61952 inodes, 247582 blocks 12379 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=255852544 8 block groups 32768 blocks per group, 32768 fragments per group 7744 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376
I have seen this behavior with several drives. I do not see this poor performance with IDE.
I am using EHCI USB with all of the latest patches. I have made only minimal changes. Our code base is based off of 2010.09 but I have applied all of the GIT patches to USB and the filesystems with only a couple exceptions in the USB code (which do not affect performance).
I don't have any other platforms to test the USB performance with.
-Aaron