Which is the limitation to the SD/microSD card size for Garmin devices ?
There are several products that can accept expandable memory cards in SD or microSD format. These cards, for some devices, can be used to store maps,active track-log data, however, all expandable memory devices can utilize the additional memory to store MapSource products.
There are limitations to the size of SD/microSD card used and to the number of detailed mapping segments that can be recognized by a device.
these limitations can be:
* There is no limitation to the size of SD/microSD card used but the device will only recognize 4GB (in some old devices 2gb) of detailed mapping
* Each expandable memory device will be able to recognize up to 2,025 detailed mapping segments
If 2,025 detailed mapping segments are loaded to an SD/microSD card but does not reach 4GB worth of data, the unit will not show any more detailed mapping than what is provided by the mapping segments.
What is a mapping segment?
Detailed mapping software, such as City Navigator NT or Topo 24, on a DVD format will contain many mapping segments within MapSource or MapInstall. A mapping segment is one selectable area of mapping that can be transferred to the device.
The segment selected to be transferred to the GPS is highlighted in Mapsource in pink.
BUT...WHAT ARE THE LIMITS, REALLY??
Mapset Segment Count:
As far as I know the mapset limit should be still 2025 map segments on most Garmin devices, regardless of filesize. (MapSource might not care but your device might choke anyway if there are too many segments.)
But, Oregon and Colorado Montana and 62s can handle mapsets with at least 4000map segments. There appears to be some evidence in the Garmin Colorado and Oregon Wiki from actual use that supports the 4000 number.
Basemap+preloaded map+user added map=max 4XXX (4096? 4k ?)
The 60CSx supports a maximum of 2025 map segments by comparison.
If you click to the "Maps" tab in MapSource as you're selecting map segments, you can see how many segments you have selected and the filesize (down near the bottom of the tab) before you transfer to the card.
Limits of FAT16/FAT32:
MapSource (actually, Windows) will absolutely limit the file size according to the following:
Volume (Disk) Size: FAT16 = 2GB ..... FAT32 = 32GB
File Size: FAT16 = 2GB ..... FAT32 = 4GB minus 2 bytes
So if your 8 GB card is formatted to FAT32 you can put 8GB of files on it but none of them can be larger than 4GB minus 2 bytes each.
It's a limit of the FAT16 and FAT32 specifications, not MapSource or the devices.
The nüvi units are compatible with both normal Secure Digital (SD) data cards and Secure Digital High Capacity (SDHC) data cards. (FAT32 formatted)
16gb SD card is confirmed to work in Garmin 265WT,Nuvi 350,Nuvi ,Zumo 660, Nuvi 1460,Nuvi 760, 62s
32 GB, Class 10, in the case of 3490-
-----from Garmin FAQ-----
Question: What is the largest SD (Secure Digital) card that my nüvi can accept?
As long as your nüvi has the most recent version of system software your nüvi will be SDHC (Secure Digital High Capacity) compatible. This means that there is no limitation to the size of SD card that your nüvi will accept.
To ensure that your unit has the most up to date system software please use our WebUpdater program
Although any brand of SD or microSD card should work without any problems, Garmin recommends using SanDisk or Kingston brand cards. Most SD and microSD cards work with out any issues however Ultra, High Speed (such as 133x or faster), or SD and microSD cards specifically used for high end or professional electronics might not work.
can you share your experience ?
Lolypop000 and other users' experience corrected table June 2013 :