Dermot McNally <dermotm@gmail.com> writes:
2009/8/10 Greg Troxel <gdt@ir.bbn.com>:
For receivers with a 2GB uSD, I think one wants tiles pretty big. I have 2009 vintage Garmin proprietary maps, and all of New England is in 2 tiles, and the .img I think are about 25 MB each. I also have a 2002 or 2003 vintage receiver and proprietary map data, and that has tiles that are about 1-4MB. This lets me choose what I want to fit in the 19 MB internal memory. There are still some devices like that around and useful, so I can see a demand for ~3 MB tiles. But, for the 2GB types, tiles that are more like 25 MB seem better.
Greg, is that map with the larger tiles in NT format? I've noticed that these tend to be bigger, and indeed, the devices that support this format are also newer and more powerful.
Yes, the 2003 is the old format (I think), and the larger tiles definitely NT. But, you can get an etrex without the uSD (why you would, I don't know, but you can) and those have I think 24MB of internal memory, which is not all that different from 19MB. I think the NT tiles will fit one of them in that, which is great unless you are on the border between two tiles. I don't know if NT is more or less space efficient. I can't imagine it's all that different.