USB flash drive copy speed anomaly

[Opinicus]

Using WinXP Home with all updates in place.

When I try and copy the My Name folder under C:\Documents and Settings
(1,119,992,974 bytes) to a 1.5 gig USB (2.0 natch) flash drive it takes a
L...O....N.....G time, on the order of half an hour. If I zip that folder to
a single file (832,088,600 bytes) first, the copy takes only two minutes.

Why?

 

[Uwe Sieber]

Using WinXP Home with all updates in place.

When I try and copy the My Name folder under C:\Documents and Settings
(1,119,992,974 bytes) to a 1.5 gig USB (2.0 natch) flash drive it takes a
L...O....N.....G time, on the order of half an hour. If I zip that folder to
a single file (832,088,600 bytes) first, the copy takes only two minutes.

Under XP removable USB drives that are FAT formatted have
no write cache. In result every single file is written
separatly to the USB disk and threrefore the access
time it the most significant factor when lots of small
files are written.

The solution is to get the write cache activated. As far
as I have experienced under XP the only way to get a write
cache is to format the drive with NTFS:
http://www.uwe-sieber.de/usbstick.html


Greetings from Germany

Uwe

 

[Opinicus]

Under XP removable USB drives that are FAT formatted have
no write cache. In result every single file is written
separatly to the USB disk and threrefore the access
time it the most significant factor when lots of small
files are written.

The solution is to get the write cache activated. As far
as I have experienced under XP the only way to get a write
cache is to format the drive with NTFS:

Thanks for the info UWE. I checked and the drive is FAT formatted.
Unfortunately formatting it with NTFS is not possible for some reason. The
only options under "Format" are "FAT" and "FAT 32".

I'm using this device as a worst-case emergency backup anyway so having
everything stuffed into one big zip file is not a serious problem.

 

[Uwe Sieber]

Thanks for the info UWE. I checked and the drive is FAT formatted.
Unfortunately formatting it with NTFS is not possible for some reason. The
only options under "Format" are "FAT" and "FAT 32".

Yes, you have to switch the removal policy for the USB
drive before:
Double click the green 'save removal' tray icon, check
'Display device components'. Then right click your USB
device (second level in the tree) -> Properties.
Here is the tab 'Policies'. Switch to 'Optimize for performance'.
The description text claims that this would enable write
caching but is true for USB drives only that appear as
'local disk' in the Windows Explorer. For removable disks
it enables only NTFS formatting. But NTFS formatted removable
drives get a write cache under XP despite the policy...

I posted the link to the german page, here is the right one:
http://www.uwe-sieber.de/usbstick_e.html


Uwe

 

[Opinicus]

Yes, you have to switch the removal policy for the USB
drive before:
Double click the green 'save removal' tray icon, check
'Display device components'. Then right click your USB
device (second level in the tree) -> Properties.
Here is the tab 'Policies'. Switch to 'Optimize for performance'.
The description text claims that this would enable write
caching but is true for USB drives only that appear as
'local disk' in the Windows Explorer. For removable disks
it enables only NTFS formatting. But NTFS formatted removable
drives get a write cache under XP despite the policy...

I posted the link to the german page, here is the right one:
http://www.uwe-sieber.de/usbstick_e.html

Very useful. Thanks. I used "CONVERT" (it's been so long that I used it that
I'd forgotten about it) to change the flash drive to NTFS and now the
transfers are lightning fast.

You've been a big help. Thanks again.