Slow USB transfer for FAT32
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Won't Fix
|
Undecided
|
Unassigned |
Bug Description
This bug is "spin off" of bug "file transfers on USB disk are very slow "
https:/
I did some tests and found out that when writing to my USB flash disk the speed is quite low. I observed that the situation is improved (or rather resolved) if the flash disk is formated as ext3, so this can be a problem with fat32. I also have an external USB hard disk (NTFS formated) which seems to work in satisfactory way. This further supports the fact that the problem affects fat32 formatted disks.
I ran several tests according to https:/
Since the problem is more obvious for very large files I let dd create a test file for about 5 minutes, just to be on the safe side.
The facts:
When I generate a load using dd for about 5 minutes the results from dd are:
FAT32 USB flash disk: 1617933312 bytes (1.6 GB) copied, 305.66 s, 5.3 MB/s
ext3 USB flash disk: 41091136 bytes (41 MB) copied, 3.85154 s, 10.7 MB/s
NTFS Hard disk: 4294967295 bytes (4.3 GB) copied, 290.644 s, 14.8 MB/s (maximum file size was reached in less than 5mins
The same USB flash disk performs roughly twice as fast on a Windows XP machine.
The USB flash disk specificstions state that it is able to write at 10MB/sec and read at 15MB/sec
The hardware
M/B --> ECS GF7050VT-M5 (nvidia 7050 chipset), with the latest BIOS
USB Flash Disk --> Crucial Gizmo! plus 4Gb (JDOH4GB-730)
Hard Disk --> Western Digital WD300 connected with no-name IDE-to-USB equipment.
The sofware
Kubuntu Jaunty 64-bit with all the latest updates installed
description: | updated |
description: | updated |
affects: | ubuntu → linux (Ubuntu) |
tags: | added: acpi-table-checksum |
Changed in linux (Ubuntu): | |
status: | New → Confirmed |
tags: | added: b73a1py79 |
Here is dd wrote in each case, after the test was concluded:
For USB flash disk (fat32):
avlass@ avlass- desktop: ~/Desktop/ Test$ dd if=/dev/zero of=/media/ CRUCIAL/ test-file bs=32
^C50560416+0 records in
50560416+0 records out
1617933312 bytes (1.6 GB) copied, 305.66 s, 5.3 MB/s
For USB flash disk (ext3):
avlass@ avlass- desktop: ~$ dd if=/dev/zero of=/media/ disk/test- file bs=32
^C1284098+0 records in
1284098+0 records out
41091136 bytes (41 MB) copied, 3.85154 s, 10.7 MB/s
For USB Hard disk (NTFS) avlass- desktop: ~$ dd if=/dev/zero of=/media/ disk/test- file bs=32 disk/test- file': File too large
avlass@
dd: writing `/media/
134217728+0 records in
134217727+0 records out
4294967295 bytes (4.3 GB) copied, 290.644 s, 14.8 MB/s