4GB Topram in FAT32 and FAT16 works w/ PPC6700.
The problem is, there are some software that dont realize miniSD larger than 2Gigs exist; hence, causing some errors. One example is the HTC camera, it shows that there are no space left on the card, eventhough it's still 3.5Gigs Free
. But if a dummy files is used to make it < 2gb, it works fine. That's why some user suggest it to partition it to 2Gigs; mainly for compatibility with some softwares.
But that was my experience since > 6months ago. Maybe all those problematic softwares got smarter after the ROM/version update
.