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When copying large files or testing writespeed with dd
, the max writespeed I can get is about 12-15MB/s on drives using the NTFS filesystem. I tested multiple drives (all connected using SATA) which all got writespeeds of 100MB/s+ on Windows or when formatted with ext4, so it's not an alignment or drive issue.
top
shows high cpu usage for the mount.ntfs
process.
AMD dual core processor (2.2 GHz)
Kernel version: 3.5.0-23-generic
Ubuntu 12.04
ntfs-3g
version: both 2012.1.15AR.1
(Ubuntu default version) and 2013.1.13AR.2
How can I fix the writespeed?
1With the same Ubuntu 2015.04 laptop, I formatted to NTFS a 320GB external hard disk and a 32GB USB stick. Copying 2GB of pictures to the first one was taking forever (6 hours left estimated after 30 minutes), but to the second one (USB stick) it only took a minute or two. I did not change any settings between the two. – Nicolas Raoul – 9 years ago
Have you tried testing dd with raw drive access (on the drive or partition, doesn't matter)? Note that testing that way will destroy the filesystem and will lose any data on it. It will bypass the NTFS drivers entirely. – Bob – 12 years ago
Yep I just did, the result is
149MB/s
. – Zulakis – 12 years agoJust out of curiosity I have to ask if this drive is one of those 4k drives and if therefore your filesystem might be unaligned somehow?! – Waxhead – 12 years ago
try bonnie++ and what kernel are you using? uname -r – cybernard – 12 years ago
bonnie++ produced similar results. read speed is faster then write (about
60mb/s
), still not nearly the possible150mb/s
though. I added kernel andntfs-3g
versions to my question. – Zulakis – 12 years agoWhat options did you try for dd? the block size should be at least 65536 and a large count size? If dd runs in less than 2 min the samples size is to low. Try: dd if=/dev/sda of=/dev/null bs=65536 count 10000 – cybernard – 12 years ago
dd if=/dev/random of=/dev/sda bs=65536 count=10000 – cybernard – 12 years ago
655360000 bytes (655 MB) copied, 49.2048 s, 13.3 MB/s
– Zulakis – 12 years agoIf you double the block size to 131072 and 262144 do the speeds increase at all? – cybernard – 12 years ago
Yes, it increases a little bit but only about 1-3 mb/s. Increasing te block size further doesn't increase the speed anymore though. – Zulakis – 12 years ago
How large are the files you're moving? The overhead of file creation will dominate when transferring small files. – HABO – 12 years ago
I am copying single files with sizes between 10-15GB. No small files overhead. Also, when testing with
dd
(which ultimately writes one single file), the write rates are as bad as when copying. – Zulakis – 12 years ago4I believe that the free version of NTFS-3G is crippled so that it uses 4 KiB writes with no caching, causing extremely slow write performance on SSDs and USB drives. The company behind the driver suggests buying the commercial version for better performance. Apparently no-one cares enough to actually fix (and if necessary, fork) the open source version because this problem has been around for almost a decade, ever since NTFS-3G was first released. – Tronic – 11 years ago