> Looking at modern hard disks, I'm unconvinced we could even mass-produce
> something like that today.
>
> A 40mm radius is comparable to a 3.5" disk, which are generally 5,400-7,200
> RPM. 15,000 RPM is the fastest available, but those tend to be low-capacity
> and
> expensive, and are often 2.5" drives with a huge heatsink. We could perhaps
> rotate a very narrow smaller cylinder faster still but then the capacity
> suffers further, and the seek time would start to dominate.
I Am Not An Engineer(tm) but it seems to me that a taller cylinder
should be less prone to wobbling on its axis than a flat disk,
particularly if it's built at the scale of the drums I've seen at the
CHM where there's room enough to really bolt that sucker down. Bit
different than a 3.5" box with a stack of thin metal platters in it,
I'd think.
