When I sync files, it goes only about 4MB/s while my brothers Galaxy S2 does it, I'm guessing since I can't see the MB/swhen it's transfering to the S2, around 17MB/s.

How can one fix slow write speeds?

Oh, and I forgot to tell you: on my brothers laptop, I get the same 17MB/s as GS2. But I use the PC and get 4MB/s vs. 17MB/s.

Thanks for the help!

I get around 9MB/s while transferring large file from my n900 to win7 pc and I guess that's not slow.

Your post is pretty confusing to me btw.

Is it? Well, let me try again. I copy files to my N900 at a really slow speed which is not normal, as when I got it new, it transferred at 17MB/s. Nowadays it does only 4MB/s. Is there an explanation for this? And how can I fix it?

There is an issue for some unknown reason. Every time I connect, I get a message that N900 is not a 2.0 device. Restart the computer while your N900 is still connected and it'll do very high speeds.

scandisk and check the check surface for errors..
it should help..
usb port speed on pc also matters 2.0 is slower then 3.0.. if its a old desktop, u might wanna check that too.. and depends.. large files get transfered faster then smaller files which are large in number..
a 700mb file will use more speed then 100 13 kb files..

Yeah. It is quite old, but I use a Galaxy S2 on the same exact USB cable and same USB port and still the S2 goes lightning fast! I will try resetting it. Maybe it is the USB 1.0-2.0 proble. Will report!

fsck of the filesystem helped a lot when mine did that. doing it through backupmenu is best, in my opinion

I restarted with the phone still attached. It did nothing. How do I perform fsck again?

I did the fsck with Bootmenu-or whatever it is called. I did fsck MyDocs, but nothing changed I'm running out of options here...