Since 9.5mm 2.5" 1TB drives are now available, my conclusion is that 500GB per platter is a reality. This means that 1.5TB drives at 12.5mm are just a matter of assembling them.
I travel with about a dozen 1TB portable drives (media etc.) but I can’t keep lugging more drives as my storage needs expand. My ideal portable drive size right now would be 3TB but I realize this is not yet realistic (although a six platter disk would do it, of course).
Still, 1.5TB should be available in stores anytime now, given that 500TB per platter appears to have been reached. When can we expect this?
