Street 550c

I contacted Garmin support 3 days ago with a similar question. I wanted to make sure the SDHC was computable. He said yes but cautioned me to keep the size at 4G or less. I have read on other forums that larger SD Cards may work but often have difficulty ( I can't remember what). This seemed to confirm the answer from support.

I use 4GB for 2 years now...

Lot of comment on this site about slow loading time (When you start GPSr with SD card inserted)etc. Some say slow some say no. What about you?

I've read the same... you COULD use a card over 4GB, but if you put more then 4GB worth of music on there, it will start to lag out the whole unit...

maps don't refresh correctly, menu's lag, etc. So, there really is no point in putting a card larger then 4GB in it

I have a 2 Gig sd card in my c580. I don't have but 500 meg or less used on it and it has not affected boot time. If I am using directions from the unit then it does lag a bit, but not terrible. Most of the time I am in map view...

Daniel

I have a 2 gb and it is fast.