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Extremely low performance with external USB exfat HDD

Posted: Sat Aug 30, 2014 2:55 pm
by funnyface
Man, i love Raspbmc.

works great except of very slow performance with the USB exfat format HDD i connected.
copying a file inside the HDD or from/to the network yields extremely poor speed, even for USB2.
it has a separate power supply.

both partitions of this HDD are not mentioned on the fstab so i guess they are loaded automatically.
these how the disk looks with mount -l

Code: Select all

/dev/sda2 on /media/New Volume type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096) [New Volume]
/dev/sda3 on /media/New Volume_ type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096) [New Volume]
any ideas why this is the case and what can i do to solve this ?

Re: Extremely low performance with external USB exfat HDD

Posted: Wed Sep 03, 2014 3:22 am
by elatllat
quantify?

17MB/s is the max imposed by network and drive both on USB 2.
http://en.wikipedia.org/wiki/USB#USB_2.0

Re: Extremely low performance with external USB exfat HDD

Posted: Wed Sep 03, 2014 3:31 am
by AndrewS
Linux (especially on the Pi) always has slow read/write speeds to exFAT or NTFS filesystems, because they're implemented as user-mode filesystem drivers, rather than kernel-mode (because of the patents etc. Microsoft has on them).

The 'fix' is to reformat your HDD with a Linux-native filesystem such as ext4. Which may or may not be an option depending if you need to use the HDD with non-Linux systems too...

Re: Extremely low performance with external USB exfat HDD

Posted: Wed Sep 03, 2014 3:46 am
by elatllat
you can use "top" to see it you are CPU bound.