Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

My SSD Samsung 840 was used as OS drive for a Windows 7 based machine.
I want to use it now as external SSD drive under Ubuntu.
I formatted it with Gparted to remove recovery partitions of Windows (that were unallocated).
I have noticed that now the disk is much slower than before formatting.

What do I have to do ?

Thanks !

share|improve this question
1  
You mean you connected it with USB to your machine? –  falconer Jan 24 at 23:14
    
Yes that i what I did. –  Gonzague Jan 25 at 21:43

1 Answer 1

up vote 2 down vote accepted

If you connect your SSD with USB to your computer you are limited by the USB bandwidth.

A Samsung 840 SSD can do ca. 500MB/sec read, the USB 2.0 has a theoretical limit of only 60MB/sec but practically it can only do about 30MB/sec. This is likely your problem, USB2 is just too slow.

With an USB3 port (and USB3 cable and USB3 capable casing) you should be able to utilize most of the speed of your SSD even externally. (or with an eSATA port, or something other which is faster than USB2.)

Also if your drive is formated to NTFS it will be significantly slower on linux than on windows, because the linux NTFS driver is a slower one. This is because the NTFS file system is proprietary, and Microsoft didn't release the specifications of it, so the guys who wrote the linux driver had to reverse-engineer the file system. If you swtich to a linux native file system, like ext4, you will likely get better performance.

share|improve this answer
    
For copying files from internal SSD to the external SAMSUNG SSD connected with USB 3.0 port, it averages 130 MB/s, I think I got more (around 180 MB/s) before formatting the Samsung SSD. The speed indicator in Ubuntu keeps lowering until it reaches that speed (starts at around 200 MB/s). BTW, what is the correct format file to use to format a SSD drive as external or secondary non system disk ? NTFS or something else ? –  Gonzague Jan 26 at 16:25
1  
@Gonzague Is this a 128GB one? It has exactly 130MB/sec write speed at max. See it in this doc. If you use only linux then stick with ext4. If you also need windows access for the SSD use NTFS. Also note that if you use NTFS it will be slower on linux, because the NTFS file system is proprietary, the linux drivers are only reverse engineered and because of this NTFS drives are slower on linux than on windows. So if your drive is currently NTFS, that could cause also a slowdown on linux. –  falconer Jan 26 at 16:40
    
it is a 500GB, and I used NTFS. Ok, I will format it in EXT4. Thanks. –  Gonzague Jan 26 at 18:57
    
Ok, switched to EXT4, and now it is much faster ! Thanks ! –  Gonzague Jan 26 at 19:49

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.