awesomo

I'm trying to copy map files (bcnav/back country navigator) on to a 32gb micro SDHC, which I created on Mobile Atlas Creator . These files are very small, about 2-10kb each, but there are ALOT of them (Upwards of about 500k files). The following are the approx total 'size' and 'size on disk' of the files on varying formats:

1) On my PC/(120gb hard drive): Size= 600MB/Size on Disk= 1.5gb
2) On another 8gb mSDHC: Size=600MB/Size on Disk = 3.7gb
3) On the 32gb mSDHC: Size=600/Size on Disk = 14gb !!!!

Question: Why is the Size on disk so large on the 32gb sdhc? The whole point of upgrading from the 8gb to the 32gb, was to have the capacity to copy more map files. But at this rate, I've already consumed half of my new sdhc?!