From mboxrd@z Thu Jan 1 00:00:00 1970 From: tfb@tfeb.org (Tim Bradshaw) Date: Tue, 17 Jan 2017 13:09:13 +0000 Subject: [TUHS] Questions for TUHS great minds In-Reply-To: <99f1301695eb38762765b91bff57b0486bc71af6@webmail.yaccman.com> References: <99f1301695eb38762765b91bff57b0486bc71af6@webmail.yaccman.com> Message-ID: <512ABFFE-C238-45CA-9C43-CF9A84E4DE49@tfeb.org> On 11 Jan 2017, at 18:34, Steve Johnson wrote: > > IMHO, hardware has left software in the dust. I figured out that if cars had evolved since 1970 at the same rate as computer memory, we could now buy 1,000 Tesla Model S's for a penny, and each would have a top speed of 60,000 MPH. This is roughly a factor of a trillion in less than 50 years. This doesn't mean that the process will continue: eventually you hit physics limits ('engineering' is really a better term, but it has been so degraded by 'software engineering' that I don't like to use it). Obviously we've already hit those limits for clock speed (when?) and we might be close to them for single-threaded performance in general: the current big (HPC big) machine where I work has both lower clock speed than the previous one and observed lower single-threaded performance as well, although its a lot more scalable, at least in theory. The previous one was POWER, and was I think the slightly mad very-high-clock-speed POWER chip, which might turn out to be the high-water-mark of single-threaded performance; the current one is x86. Obviously for a while parallel scaling will mean things continue, but that crashes into other limits as well. I think we've all lived in a wonderful time where it seemed like various exponential processes could continue for ever: they can't. --tim -------------- next part -------------- An HTML attachment was scrubbed... URL: