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[Darek <1242085@xxxxxxxxxxxxxxxxxx>]

Public bug reported:

Problem description:
I noticed very very low write speed to USB disks, especially to the new ones with USB 3.0. The "Disks" tool shows write speed about 7 MB/s !!! After start benchmark this tool shows write speed about 17 MB/s but imidiatelly goes below 10 MB/s. Same low speed during copy e.g. 3GB file manually to USB 3.0 disk. There is no such problem with read or access speed, only write. Unbelievable !!! 

OS: Ubuntu 13.10 (64 bit mode).
Kernel: 3.11.0-12-generic
Disk: Kingston DT Ultimate G3 (32GB)

Similar low write speed problem is for disks: 
- Seagate Expansion Portable Hard Drive 500GB (model inside ST500LT012-9WS142)
- Verbatim Store 'n' Go SuperSpeed USB 3.0 Portable Hard Drive 500GB (model inside ST500LM0 12 HN-M500MB)

I report this bug from PC, but the same bug is on my laptop Asus X55U. 
Even the write speed on my laptop is more important to me.

What I found about this bug (VERY IMPORTANT NOTE):
- In old realese 12.04 LTS disks works OK.
- In 13.04 disks works faster than it is now in 13.10.
- If disk is formatted as NTFS the write speed is the lowest. 
- If disk is formatted as EXT4 the speed is x2 better. 
- If disk is formatted as FAT32 is low too.
- No matter if disk is connected via USB 2.0 or USB 3.0. The low write speed is always the same. 
- This problem doesn't exists in Windows (so this is no hardware or BIOS problem).
- This problem doesn't exists in OpenSUSE (so this is no hardware or BIOS problem).
- There is no such problem with read or access speed. Write only. 
- No matter if there is UEFI. Laptop Asus X55U has UEFI but PC has not.
- Hardware - no matter (same is on laptop ASUS X55U, I report from my PC now)
- No matter if Ubuntu is 32 or 64 bit mode.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: Incomplete


** Tags: 3.0 kernel speed ubuntu usb

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https://bugs.launchpad.net/bugs/1242085

Title:
  Low write speed to USB disks - do something!

Status in “linux” package in Ubuntu:
  Incomplete

Bug description:
  Problem description:
  I noticed very very low write speed to USB disks, especially to the new ones with USB 3.0. The "Disks" tool shows write speed about 7 MB/s !!! After start benchmark this tool shows write speed about 17 MB/s but imidiatelly goes below 10 MB/s. Same low speed during copy e.g. 3GB file manually to USB 3.0 disk. There is no such problem with read or access speed, only write. Unbelievable !!! 

  OS: Ubuntu 13.10 (64 bit mode).
  Kernel: 3.11.0-12-generic
  Disk: Kingston DT Ultimate G3 (32GB)

  Similar low write speed problem is for disks: 
  - Seagate Expansion Portable Hard Drive 500GB (model inside ST500LT012-9WS142)
  - Verbatim Store 'n' Go SuperSpeed USB 3.0 Portable Hard Drive 500GB (model inside ST500LM0 12 HN-M500MB)

  I report this bug from PC, but the same bug is on my laptop Asus X55U. 
  Even the write speed on my laptop is more important to me.

  What I found about this bug (VERY IMPORTANT NOTE):
  - In old realese 12.04 LTS disks works OK.
  - In 13.04 disks works faster than it is now in 13.10.
  - If disk is formatted as NTFS the write speed is the lowest. 
  - If disk is formatted as EXT4 the speed is x2 better. 
  - If disk is formatted as FAT32 is low too.
  - No matter if disk is connected via USB 2.0 or USB 3.0. The low write speed is always the same. 
  - This problem doesn't exists in Windows (so this is no hardware or BIOS problem).
  - This problem doesn't exists in OpenSUSE (so this is no hardware or BIOS problem).
  - There is no such problem with read or access speed. Write only. 
  - No matter if there is UEFI. Laptop Asus X55U has UEFI but PC has not.
  - Hardware - no matter (same is on laptop ASUS X55U, I report from my PC now)
  - No matter if Ubuntu is 32 or 64 bit mode.

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