Slow Mac USB -- Crazy Idea -- Feedback Requested


With two Garmins (255W, 1450LM), three Macs, including a 2011 MacBook Air, and two operating systems (10.6 and 10.7.4 now), I have NEVER been able to connect a Garmin via USB at 2.0 speeds. Every time I'm limited to USB 1.1 speeds (12 megabits per second). I've used different cables, powered hubs, no hubs, etc. It's always slow USB 1.1. Keep reading...

My Mac sees the Garmin flash memory as a "Composite USB Device" according to a System Report. ("About this Mac...")

I was poking around in Disk Utility and saw that the internal flash memory of my 1450LM has no partition scheme. The file format is obviously FAT32, but there is no partition scheme like MBR.

I always maintain a backup disk image of the internal flash drive of my Garmins. That includes all files (including files inside the hidden "System" directory).

Question: If I were to repartition my Garmin with the Master Boot Record partition scheme and then format the sole volume as FAT32 and then restore from my disk image, would that perhaps allow my Mac to see the Garmin as a USB 2.0 Mass Storage device? Or, would I brick my Garmin?

Or, does anyone have any other ideas. Doing a map update at USB 1.1 speeds is like filling a bathtub through a straw.


I wouldn't play with the Garmins partitions

I wouldn't play with the Garmins partitions because the chance of bricking it would be very high.

Sounds like the problem lies with the macs USB drivers and not the Garmin.

Try connecting using a Windows 7 PC and see if it is faster. My windows 7 desktop and both laptops have no trouble connecting and downloading at USB 2.0 speeds with any of our Garmins.

GM Built-in Navigation system - Samsung S6 Edge+ Smartphone with Garmin Viago, Google Maps & HERE Apps

It is faster under Windows...

I forgot to mention. The USB transfer rate when connected to Windows 7 is normal.

I probably won't repartition it until I'm ready to buy another one or else buy the GPS add-on for my iPod Touch. But I really want to!

I was just trying to come up with some explanation as to why the Mac operating system doesn't see the device as a USB 2.0 Mass Storage Device.

Thanks for the reply.


The Garmin isn't Mac certified, ie, it hasn't been tested by Apple, had a custom firmware made for it which allows it to be identify as being certified equipment, and had a 175% price hike for being Mac compatible.

Seriously though, Garmin always had lousy support for Macs, so like was pointed out already, it's most likely the drivers that are preventing the Garmin unit from working at USB 2.0 speeds. Nothing you can do about that, other then hound Garmin to update their Mac drivers.

Not worth the effort

Thanks for the info.

It's not worth hounding Garmin because standalone GPS units, like standalone consumer cameras, are on their last legs.

If they haven't fully supported the Mac operating system by this time, they won't in the future. Their software efforts are now going into the ipad/ipod touch apps.

Garmin Paperweight

I wouldn't recommend messing around with the Garmin's partitioning. You could likely turn it into an expensive paperweight.

-- where the heck am I?

I Have Not Had This Problem

I am using a MacBook Pro (2011 model) running 10.7 Lion. I have not experienced any problems with my Garmin being detected as a USB 2 device.

I have installed the Garmin Communicator Plugin and the WebUpdater that I also use with my Edge 800. I don't know if that really had anything to do with it though.

I've also had BaseCamp and the Training Center installed before, but I typically use the web interface now because I can also see my information from my Windows computer.

Not sure if this may help you, but you can check out the Garmin Software for Mac on their website; If you already have any of this installed, make sure you've got the newest updates - you're MacAppStore will have some of them with full Apple Support.

Hopefully, you'll get it sorted out.

And now, back to your regularly scheduled forum - already in progress . . .

I never had a problem with....

my Garmin Nuvi 660i, Nuvi 360 or Street Pilot appearing on the desktop of any of my Macs as an external drive in OS 10.6.8 or earlier. What OS are you using?

RKF (Bethesda, MD) Garmin Nuvi 660, 360 & Street Pilot