On Fri, 27 Mar 2009 14:41:10 -0500, Chase, John wrote: >> >> Well, if IBM's new DASD architecture were manufactured in the same >> manner as previous DASD devices, you would have 278,921,216 tracks >> on each surface. What diameter do you think such platters would be? >> How long would it take the access arm to traverse the radius? > >How much power would it take to spin them fast enough to be usable? :-) > Long ago, I attended a Preview of XA presentation at which the IBM presenter (Bill Malleck?) stated that smaller rotational latency could be achieved only with smaller platters. Mechanical disruption happens at a surface velocity roughly the speed of sound -- sqrt( Young's modulus / density ). The problem engineers were confronting was oxide flying off the substrate. By analogy, "Have you ever watched the chef making pizza, throwing the dough in the air to form the crust? Notice that he only puts the sauce on after."
Tetrahedral carbon platters? Graphene? (They're working on it.) -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
