Memory Card Capacities

[Andy49]

Is there a GB limit beyond which today's DSLRs can not utilize the flash memory. For example, 256 GB

[TCav]

Cameras use storage devices that are compatible with other devices, so they have some portion of conventional computer operating systems in firmware. Earlier cameras used to use lesser capacity devices (<4GB) which computers used the FAT16 file system to manage. FAT16 is still used for lesser capacity devices because it is more effecient for them. But FAT16 couldn't handle greater capacity devices (>=4GB) so Microsoft developed the FAT32 file system which supports devices with a storage capacity of up to 2,048GB.

Earlier cameras only used FAT16, and so they were limited to cards with capacities of less than 4GB. Current cameras can use FAT32 for larger cards, and so are limited to 2,048GB.

[waxdr]

TCav, I concur:
The maximum commercial capcity due to be offered from a FAT32 card is 2TB - in fact, Sony have already announced 2TB Pro Duo cards: http://www.****************/dump/images/MS2TB.jpg

[Andy49]

Wow! I remember my first IBM pc with 256k of RAM, no hard drive and 360k of floppy disk. Just amazing.

[TCav]

I remember my Commodore VIC-20 with 3K of RAM, and a cassette drive. I eventually upgraded the RAM to 8K and a SS/SD floppy disk drive.

[JimC]

Originally Posted by Andy49

Is there a GB limit beyond which today's DSLRs can not utilize the flash memory. For example, 256 GB

One of the problems we're seeing now is that FAT32 is very limiting in areas like maximum file size, number of directory entries and more. For example, there is no way that I could personally use it for disks I use for backups, since my file sizes are just too large (image files of partitions, etc.), since FAT32 is limited to a maximum file size of 4GB.

The limitations associated with FAT32 are going to be a much bigger problem as time passes (especially with video, since the existing 4GB file size limits mean that you need to limit recording length)

As a result, newer memory card formats are probably going to migrate to the new Microsoft exFAT (Extended FAT) file system at some point, proprietary or not.

http://msdn.microsoft.com/en-us/library/aa914353.aspx

This file system gets around the 4GB file size limitation you have with FAT32 (the file system used by most current camera models).

Some newer memory card formats are already going to use this new system (for example, the new SDXS cards are going to use exFAT). So, I expect to start seeing cameras supporting this newer format as time passes (abandoning FAT32 due to it's limitations).

[Photo 5]

So does this have anything to do with why CF cards seem to be on their way out? I always thought CF cards were the fastest and biggest capacity on the market. I guess others are catching up......

dave

[JimC]

You can use newer file systems like exFAT on a Compactflash card (as well as a number of other file systems that could get around the limitations of FAT32 if manufacturers go with something else at some point). So, I don't expect to see them going away anytime soon.

[TCav]

CF Cards are physically bigger, so they're simpler and cheaper to manufacture. They're also simpler and cheaper to impliment (except for their size.) Plus CF cards are widely used in other devices.

CF Cards aren't going anywhere for a while, but they are being replaced by other card formats (most noteably by SD cards) in devices that need to be smaller and lighter, like P&S digicams and entry level dSLRs.

[Photo 5]

Its just that I've been noticing that all but the top of the top of the top of the top of the line cameras seem to be getting away from using CF cards. Look at the Sony cameras as an example the A200 and A350 used CF cards. Their replacements use SDHC cards etc.