4 Replies Latest reply: Dec 18, 2009 4:59 AM by Robin Bonathan
Mario266 Level 1 (0 points)
I have two (different) 64gb USB-Flash-Disks and both are not working ...
In the beginning I thought it would be a Problem of the Flash-Disks, but if I format them on my old WinXP computer with the HP-Tool on FAT32 they are working on Windows-Computers - and also with my Airport-Extreme.

The Problem:
If i connect the Memory-Stick with my MacBook it is shown as a external Hard-Disk (? - other Flash-Disks are always shown as USB-Memory)
If i copy some Files on the Stick it stops exactly when 4gb are written on the Stick - it disconnects from the System and I get a Error-Message: "reading or writing of the File was not possible"
(i tried different files with no more than 800mb - so it's not the 4gb Problem of the FAT32-System)
If I try to Format the Stick with the MAC Hard-Disk-Tool the Program freeze (if i don't use FAT)

Is there Somebody with some Ideas? - I really need help ...

Now I have these expansive Memory-Sticks and I cant use them
(or just if i connect them by wlan and the Airport-Extreme - where I can use them normally ... but it is so slow ...)
... and I can't give them back, because they are working everywhere (exept my Mac)

MacBook Air, Mac OS X (10.6.2)
  • K T Level 7 (23,705 points)
    Hi Mario266 & welcome to the forums...

    If you must use OS X/Disk Utility, only format them for Windows/Dos/FAT32.

    In any case, be sure to not have too many USB devices on the bus at one time to avoid risking voltage supply issues, etc. Also avoid using non-USB2 (earlier) devices. Strip down to just keyboard & mouse and then your flash device to test.
  • Mario266 Level 1 (0 points)
    Thanks for the answer ...
    ... but i tried this already
    ... the Flash-Memory is the only device on the Bus - and I only can use the FAT-Formart (otherwise my the Disk-Utility stops working)
    But even with the FAT-Format I have the Problems - that only 4gb can be written on the USB-Stick ...
    ... at the moment I just use it with the Airport-Extreme (where it is working)
  • Robin Bonathan Level 1 (90 points)
    Did you find a solution to this ?

    I have just purchased a 64GB flash USB stick but cannot format it in Mac or Windows.

    Not sure if disk or OS is at fault. Get an error message when try to format to say there is an error.

    Any ideas ?

  • Robin Bonathan Level 1 (90 points)
    Just to add some more info to this.

    From the mac I can format it as FAT 32 but not Mac Journalised etc.

    Problem with that is windows does not recognise it and also limited on file size i can put on.

    On windows 7 it will format it with exFAT but the Mac will not recognise.

    Any thoughts ?