[ubuntu] Slow USB, cannot enable DMA

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http://ubuntuforums.org – I have been googling this issue for a while now, but have not been able to get this resolved. I have a Toshiba satellite with this spec - (Core duo, 2 GB RAM, Intel ICH7 ). When I try to write on a USB pen drive / passport drive copying speed drops from 10-15 MB/s to 4-5MB/sec with high CPU usage. I suspect this is because DMA is not enabled. I am not able to enable DMA using the hdparm. $ sudo hdparm /dev/sdb1 /dev/sdb1: HDIO_DRIVE_CMD(identify) failed: Invalid exchange readonly = 0 (off) readahead = 256 (on) (Hardware)