gwyn@smoke.BRL.MIL (Doug Gwyn ) (12/03/88)
In article <960@vsi.COM> friedl@vsi.COM (Stephen J. Friedl) writes: >Why is this? When I was hacking on the VAX, nobody could ever >tell me how long anything took, and empirical measurements were >pretty tedious. Is it laziness on the vendor's part or are there >good reasons for this? Exact computations of instruction timings, already quite difficult for the VAX-11/780, have become so context-dependent as to be not worth attempting. Time taken for a given instruction depends on such things as cache hit rate, fault rate, instruction mix, and so forth. What really matters is overall system performance, which is a statistical matter.