Sun Microsystems Launches OpenSPARC Project

Posted Dec 6, 2005 22:55 UTC (Tue) by gnb (subscriber, #5132)
In reply to: Sun Microsystems Launches OpenSPARC Project by nix
Parent article: Sun Microsystems Launches OpenSPARC Project

> Note that Intel, for instance, no longer even publish *instruction
>timings* for their CPUs (although AMD do).
Annoying though that is, I suspect it's almost unavoidable given the
complexity of modern CPUs ("well, it'll take this many cycles unless it's
a mis-predicted branch, or one of the registers it uses has a dependency
on a previous instruction, or ..."). In fact I'd be interested to know
which vendors have real instruction timings for their CPUs as opposed to
statistical averages based on simulating (hopefully representative)
benchmark kernels.

Sun Microsystems Launches OpenSPARC Project

Posted Dec 6, 2005 23:40 UTC (Tue) by khim (subscriber, #9252) [Link]

You can give pretty good approxymation for 99.999% cases - enough for GCC developers, for example (even if may be not for hand-assembly). But then you'll be forced to admit that your CPU can sometimes spend 50-80 CPU ticks as heater without when no actual work is done - and that's just embarassing...