FAT16 vs FAT32 Write Speeds?

[FerdFerd]

As an experiment in testing Alex Pruss's CryptDrive, I formatted a 1GB SD card as FAT32 in the card reader on my PC. If I allow Palm to format the card, it uses FAT16.

I've noticed that the write speeds are very slow to the FAT32 formatted card. It's much, much slower than FAT16, including when trying to transfer files to it from the computer, not just the TX. My first clue to the slowdown was when creating the encrypted drive on the reformatted card, but I'm now transferring most of my usual files to this card for a more detailed trial, and it is taking forever for the files to write to the card.

Is this difference well known and to be expected? Is there a way to speed it up?

Finally, is there any other disadvantage to forcing FAT32 on a 1GB or 2GB card?

[Adam Helberg]

I'm interested in this topic, but have no answers. I notice that there is a special SD formatting utility:

http://panasonic.jp/support/global/cs/sd/download/sd_formatter.html

It says that generic formatting does not comply SD card specifications. Does anyone know about this and has anyone tried formatting with this?

My 2GB SD card is formatted in my iQue 3600, and I notice the cluster size is 32K

Adam

[Adam Helberg]

I'm interested in this topic, but have no answers. I notice that there is a special SD formatting utility:

http://panasonic.jp/support/global/cs/sd/download/sd_formatter.html

It says that generic formatting does not comply SD card specifications. Does anyone know about this and has anyone tried formatting with this?

My 2GB SD card is formatted in my iQue 3600, and I notice the cluster size is 32K

Adam

Subsequently I tried formatting using this utility. First I formatted a Panasonic 512 Meg card with this. There was a significant improvement in VFSMark scores so next I used it on my SanDisk 2GB Ultra II.

Here I got conflicting results. The VFSMark scores were slightly worse but the speed reported by another utility, CardSpeed, was significantly better. This was using the card in a Garmin iQue 3600.

I'd like to hear if others have used this formatting software and if there is any value to it.

Adam

[alegra]

FAT16 is always faster than FAT32, imho. I published an article about this some time ago on TamsPalm-DE. I also noticed that the FAT32 driver is more powerful than the FAT16 (FATFS) driver of Palm OS:

http://tamspalm.pytalhost.eu/2007/03/21/schnellerer-zugriff-auf-speicherkarten/

[potter]

I would like to see this taken further.

For a given volume size, when one selects a format (FAT16 or FAT32), this defines (because of the nature of the FAT data structures) a minimum and a maximum cluster size and a recommended cluster size. The recommended cluster size, however, was set long ago by Microsoft and was based on the performance of the then typical hard-drives. These recommended cluster size settings apparently are not ideal for non moving storage medias of today.

Therefore, I would like to see someone take this further:
For a given volume, what is the ideal format and cluster size?
Related questions:
What tool would one recommend to generate these formats?
Is there an on the Palm tool that could do these formats?
Reference:
Microsoft's Default cluster size for FAT and NTFS (http://support.microsoft.com/kb/140365)
Comments:
The default cluster size for FAT16 follows the max cluster size.
Not so for FAT32.
I doubt that Palm OS can handle a 64k cluster size.
64k clusters were only supported on a few operating systems, and in general is thus considered non standard.