On 2018-05-11 2:37 PM, John Ames via cctech wrote:
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.
They are not even metal platters anymore they have been glass for
several years now, glass is more rigid and can apparently be made
smoother than metal.
