When you buy any MMC card from the market it is preformatted with 16k block and because of these lots of space gets wasted as most of the installed program files are less than 2k. The files in the MMC are stored in the multiple disk blocks. When you format MMC using the 16k block the space is used on the cards will be 16k even the data is of 1k.
1. For formatting the card reader first connect the card reader and copy all the data from the MMC to PC and also any hidden file.
2. Start formatting the MMC using the command line format and use the /A=size
3. You can also use the disk management in the administrative tools to format the MMC card. Select FAT file system. For 256mb MMC card smallest block use 4k, for 128mb use 2k, 64mb use 1k and for 32mb use 512byte.
Now you can copy all the data from your PC to MMC card. You will find that your MMC card with some extra space 256mb card with more 30mb extra space.