On Tue, 16 Feb 2010, Ramya Desai wrote: > > Yes: hdparm, dd, and time. > Using hdparam, I was unable to perform write operations. I am using > this command as hdparm ?t /dev/sdb1 to perform reads. > Could you please let me know, how to make writes using the tool. I don't know anything about the internals of hdparm, and you can read the man page as well as I can. > > It would be better to use "of=/dev/null" because then the outcome > > wouldn't be affected by the performance of the /home/testing device. > > This is great. I am getting the same results as using Windows using > xHCI and USB3.0 cable. > > However if I connect the device to the USB2.0 port, still I see the > difference in data rates (~10MB/s) between Windows and Linux. > I am using default MS drivers in both Linux and Windows XP. > > Linux > -------- > dd if=/dev/sdb1 of=/dev/null bs=1G count=1 > 1073741824 bytes (1.1 GB) copied, 43.4181 s, 24.7 MB/s > > Windows (using Crystal Disk Mark performance measurement tool) > ------------------------------------------------------------------------------------------------- > Sequential Read : 34.556 MB/s for same device with 1.1 GB of data read. What version of Linux are you using? And which scheduler? Some people have found that the default scheduler (CFQ) leads to worse I/O performance than other schedulers. See https://lists.one-eyed-alien.net/pipermail/usb-storage/2010-January/004970.html Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
