The 60GB 32Gbit drives feature 16x32Gbit (4GB) Nand IC with 7% OP
The 60GB (55GB formatted) drive features 8x64Gbit Nand IC with 7% OP
The 100GB 64Gbit drive features 16x64Gbit (8GB) Nand IC with around 25% OP
The 120GB 64Gbit drive features 16x64Gbit (8GB) Nand IC with around 7% OP
The 50GB drives I will need to double check.