Copying to MicroSD card from Ubuntu 9.04 Is slow

Question

When I copy stuff to my class 6 16GB microsd card it seems very slow. This is true with multiple readers and computers, but I have only tested it with ubuntu 9.04. In /var/log/messages I get the following a bunch of times during the transfer:

[355335.112041] usb 1-4: reset high speed USB device using ehci_hcd and address 3
[355368.112060] usb 1-4: reset high speed USB device using ehci_hcd and address 3
[355403.116565] usb 1-4: reset high speed USB device using ehci_hcd and address 3
[355436.112041] usb 1-4: reset high speed USB device using ehci_hcd and address 3
[355470.112311] usb 1-4: reset high speed USB device using ehci_hcd and address 3
[355534.112403] usb 1-4: reset high speed USB device using ehci_hcd and address 3

Is this a bad card, I might go try it with a different OS, but maybe someone has seen this? I am copying to the first partition, the partition looks like:

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1        1822    14635183+   b  W95 FAT32
/dev/sdb2            1823        1920      787185   83  Linux
/dev/sdb3            1921        1953      265072+  82  Linux swap / Solaris

Answer 1

Have you tried other cards in the same readers and gotten transfer speeds? It could be none of the readers support the highest transfer speeds.

The resets, from what I know, could be a bad card, a bad reader, or a bad USB port. The USB or card connection could be intermittent and disconnect for a moment due to fan vibrations from the computer. It could also be drivers, but on multiple computers, it seems unlikely (unless they are all Dell).

Answer 2

Do you have an older motherboard with older USB version. There could be compatibility issue with the older (low speed) USB interface taking to device with high speed usb card.

Answer 3

I didn't think Ubuntu could use an SD card in SD mode--I thought it was using the older MMC mode because Linux can't abide by the SD consortium's restrictions on SD mode.

Short version: blame the makers of SD, not Ubuntu.

Edit: I stand corrected--user is using an SD reader over USB, not an SD reader built-in to the machine.