Befor I start, I just want to warn everyone that 4GB SD cards (different from the new SD HC card standard) are not compatible with many devices and readers. The original SD hardware standard wasn't meant to support FAT32, which is necessary for partitions over 2GB. The hardware has to be able to handle the longer addressing.

Some devices are able to use them. Probably because some engineers either by pupose or accident used hardware that can recognize 32 bit addressing. No SD devices can officially use any larger than a 2GB card because the SD standard wasn't written for it. Regardless, many can! You can check online to see if someone has tested your particular device for compatibility. Simply plugging in the card, seeing 4GB, and using it isn't enough. Incompatible readers will not be able to properly read data stored above the 2Gb address.


As you can tell, I found out the hard way that the reader interface hardware in my Dell Axim X51V and USB multi-card reader are not compatible. I can only use them as 2 GB cards (a waste). As such, I'm willing to trade my two 4GB cards for three 2GB cards. Or trade three 1 GB cards each. You can make an offer for anything else. Lord knows I may get desperate!

There are many devices these cards work fine with from what I've read, so this may be a great opportunity for someone! Large storage capacity is particularly good for digital camcorders.