Increase MMC/SD Card Storage Capacity

Hack : Increase MMC/SD Card Capacity

Risk Level: LOW

REQUIREMENTS

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• A card reader/writer
• USB Data Cable and your phone (If you don't have a card reader/writer)

PREPARATION

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• Backup your data first

FORMATTING THE CARD

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USING A CARD READER/WRITER

• Insert your MMC/SD Card on your card reader
• Click on Start > Right click on "My Computer" > and select "Manage"
• Navigate to "Storage" > and click on "Disk Management"
• Select your MMC/SD card from the list off drive
• Right click on your card and select "Format"
• Refer to the formatting opitions below

Formatting 64 - 256 MB MMC
Volume Label	Anything	This  will be your card's name
File System	FAT	Optimized for MMC
Allocation unit size	8192	Smallest allocation size for 64-256 MB MMC

Formatting 512MB - 1GB MMC
Volume Label	Anything	This  will be your card's name
File System	FAT32	Optimized for 512 and up MMC
Allocation unit size	512	Smallest allocation size for 512MB - 1GB MMC

Formatting 128MB - 4GB SD Card
Volume Label	Anything	This  will be your card's name
File System	FAT32	Optimized for 128MB and higher SD Cards
Allocation unit size	512	Smallest allocation size for 128MB and Higher SD Cards

• And click "OK"

HOW DOES IT WORK

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By default, FAT is the file system of MMC and SDC on Windows and mobile phones.
The table below shows the difference of FAT and FAT32 File System.

FAT File System
Card Capacity	Default Allocation Size	Smallest Cluster Size	Equivalent file size per 1Byte
16MB to 256 MB	16KB	8KB	16KB
FAT32 File System
Card Capacity	Default Allocation Size	Smallest Cluster Size	Equivalent file size per 1Byte
256 MB to 16GB	6KB	512Byte	6KB

Larger cluster size means more potentially wasted space.
Lets say you have 1000 files which have 1k of data each. 

BEST CASE SCENARIO:

• Use 1 Meg to store them all.

WORST CASE SCENARIO:

• Each 64k cluster only holds 1k, leading to 64Megs required to store of which 63 Megs is wasted.
• 98.4% Waste

OTHER CASE:

• It requires 4Megs to store, in which case you have 3Megs of wasted space.
• 75% Waste

In short, you should allocate the smallest possible cluster size for you to store more files on your MMC/SDC