Does the USB have to stay connected?

Anytime you do any update on your gps ,the first warning you get is BE SURE THE BATTERY IN YOUR GPS ARE FULL CHARGE.

If you are starting the Update ones you started let it finish NEVER unplug your USB cable from your Gps in the middle of an update even if it take an hour or more,Stopping your update WILL damage your gps ,making not working anymore and then you must send it back to the manufacture to have repair.If you need to use your laptop then do not do the update, they also raccomend to do the update at night before you go to bed when you wake up the next morning your update are done.

I believe that's solid advice. While it's updating just let it finish. There's gotta be something that needs fixing around the house in the meanwhile

Besides, how would you expect the update to continue without being connected to Garmin via USB??
These files don't fall from the sky!

Is there not an option to put the file on the computer?

Another concern I'd have is continuing to work on the computer while downloading a big 2+GB file. As much as it should work, my fear of an increased likelihood of corrupting the file download means that before starting a map update, I connect my nuvi, make sure the computer is set not to go to sleep/hibernation, then I leave the PC alone until the update is done.

It may not be needed, but I'd hate to lose a couple hours of download/install time for a map update and have to repeat it.

The only way I would EVER disconnect the Nuvi while performing an update is when selecting download location as computer only and then install at a later time. I would ALWAYS have a current complete backup of the Nuvi at hand should anything go wrong.

Even using this method it depends on your PC's processor, should you decide to do other tasks while downloading. Minimum should be a dual core processor but quad core is more desirable. Although my PC is capable of downloading an update while performing other tasks I would not recommend it due to the large file. time involved, and always possibility of corrupting. I have downloaded other files while performing other tasks but would not risk the chance for Map downloads.

To perform a map update while the device is not connected is to use the cloning method. This method will install the map and related files to a SD card (if you have a card reader on your computer) or thumb drive. You can then copy the installed files back to the nuvi at a later time.

It would be good to clone the Nuvi on the SD card beforehand:

http://www.poi-factory.com/node/39231

In addition, I also duplicate the Nuvi directory tree on the SD card.

When the update is done, I look through the SD card and identify all the files that are generated by the update. They are easy to identify. Just look for the files with today's date that you did not create yourself. Copy them back to their respective locations in the Nuvi.

No, the files don't fall from the sky, but I figured I could download it to my laptop and then upload it from there to my Nuvi! Ir would take more time overall (since I can't do both simultaneously) but it would allow me the freedom to move about the house!

Try it, and you will find out the answer...

I wouldn't.

I usually start the update when I'm ready for bed, and let it run overnight.

You can work during download. Size of file doesn't mater. Of course you can't do anything that cause comp to restart, log off or go to hibernation/sleep. Disk defragmentation isn't good idea either. It must be able to work normally all the time that download and map update last. And of course your internet connection can't drop during download (happens on wireless connections when signal is weak).

On downside you will have probably slower download if workload of comp will increase and/or program you are using may get "hiccup" from time to time. Other than that in correctly working system there will be no problems.