I am curious to know what kind of transfer speeds others are getting
when sending files over the USB connection to the Kindle?

According to Amazon, the Kindle uses USB 2.0. However, I have
experienced very slow data transfer rates when transfering files over
the USB connection. For example, I transfered a 50 MB mp3 and it took
10-12 minutes. I tried this from a PC (running Windows XP) and from a Mac (running OS X 10.5 and another unning OS X 10.4) with similar,
slow results. I have also transferred the file to the built-in memory
and to an SD card. Again, same slow transfer speeds in both cases.
By way of comparison, I transfered the same mp3 to an iPod and it took
about 10 seconds to tranfer.

I contacted Amazon Kindle support and, after checking with the developers, they reported back to me that the transfer speeds I am seeing are as expected for the device.

I'm not very happy with this answer as these speeds are worse than you would get with even a USB 1.1 device.

I asked this question on a different forum and one owner reported that he was able to transfer 50 MB in about 40 seconds. It seems very strange to get such a wide variance in transfer speeds for two different Kindles.

I would be very interested to hear from someone who is getting faster transfer speeds.

Thanks for any input.

Having same basic problem. Extremely slow transfer speeds using Vista and Kindle 2. Sometimes transfer speed will show 0 bytes/sec, other times 3-4 bytes/sec.

I did try a soft-reset of the Kindle 2, but that did not help.

Are you using a USB hub? Sometimes hubs and USB devices interact negatively.

I've used my Kindle 1 and 2 with a Mac Pro and saw much better transfer rates than you are reporting but I was plugged directly into the Mac Pro.

On Windows XP, my Kindle 2 shows up as a removable disc, but no directories are visible and I can't copy anything onto it. On Windows 7, I see the directories and can copy content, but it's only getting 2.28KB/sec, when it's transferring at all.

It took two hours to transfer 7.5MB in 21 books downloaded from manybooks.net. a 4.9MB MP3 is currently at the 22 minute mark, and isn't even 50% complete.

I'm not using any USB hubs. I'm hooked directly to the onboard USB.

Have any of you with slow USB speeds tried a different USB port on your computer or even a different computer?

On Windows XP, my Kindle 2 shows up as a removable disc, but no directories are visible and I can't copy anything onto it. On Windows 7, I see the directories and can copy content, but it's only getting 2.28KB/sec, when it's transferring at all.

It took two hours to transfer 7.5MB in 21 books downloaded from manybooks.net. a 4.9MB MP3 is currently at the 22 minute mark, and isn't even 50% complete.

I'm not using any USB hubs. I'm hooked directly to the onboard USB.
First thing I suggest: try another USB cable. If that doesn't fix things...

I'd suggest taking your Kindle to another computer. Every so often folks get USB flash drives with bad FLASH chips that produce incredibly poor write speeds and need to have their USB flash drive replaced. The Kindle isn't immune to this kind of failure. If your Kindle is slow with the other system then likely your Kindle has issues.

Last night I transfered about 150MB of titles from Fictionwise onto my Kindle 1 and Kindle 2 (the big re-sync) via USB and it only took a couple minutes for each Kindle to swallow everything (several hundred titles).

I have the same problems with the Kindle. In transferring my files from Calibre to the Kindle via the USB cable, it takes several minutes whereas the Sony transfer is much shorter.

OK, I think I figured it out.

I've only hooked my Kindle 2 up via USB to a Mac Pro at home.

At Home I'm not running 10.4 or 10.5.

At Work I'm running 10.5.

I hooked up the Kindle 2 via USB to my Mac Pro at work and all hell broke loose.

The culprit is Spotlight. It is sucking down all your Kindle's bandwidth creating a Spotlight index of all the content on the Kindle. I'm researching how to club Spotlight over the head and keep it off the Kindle but for now it's definitely a problem (unless you aren't using 10.4 or 10.5).

UPDATE: Go to the Spotlight control panel's Privacy tab and drag the Kindle's icon from Finder into the panel. This will create a file on the Kindle that marks it as "Do No Spotlight This Device!" If you ever notice a directory on the Kindle named .Spotlight-V100 don't delete it! That's where the file is stored, in that directory.