Why a FAT32-formatted RAM disk must have a minimum size at about 4GB?

[Danish Bronco]

Hi again,

Every time I want to create a FAT32-formatted RAM disk with ImDisk with dynamic allocation, I have to set its size to something over 4100 MB, or thereabout. Such limitation doesn't apply for other file systems.

Is there a technical reason to this?

[v77]

It's because of the cluster size.
Each file system has a minimal volume size, which depends on the cluster size. But it's for FAT32 that this requirement is the higher.

[Danish Bronco]

Oh, OK, I figured there must be a good reason for that, but I just learned something. Thanks!

[slon1024]

Danish Bronco
I too use dynamic mode with standart Size of Allocated Memory Blocks = 1mb (2^20) in Win7 x64 sp1, but minimal size FAT32 is 36860kb (almost ~36mb).

v77
Maybe easy change format for set block size as xx, xx K , xx M, for understanding some people? Or show near how much it's in, K, M ?
2^20=1mb, but 2^27=128mb. Small step for binary system, giant leap for decimal system :)

[Danish Bronco]

For the record, I played with block sizes a little bit, and found out that I could set the size of the RAM disk at 512MB in FAT32 if I chose blocks of about 1MB in size. (I think; right now my RAM disk is set in FAT and is working fine so I'll leave it that way.)