On Sunday, July 17, 2011 01:31:51 AM John R Pierce wrote: > I386 was the original 386 CPU, which ran at speeds from 16 to 33Mhz > i486 includes a few additional instructions on the 486 processor, and > IIRC, ran at speeds from 25 to 100Mhz Super minor correction: 486SX's at 16 and 20 MHz were available..... And I think a 120MHz variation of 486DX4. And then there was AMD's 5x86 at 133MHz. We have a few embedded boards running controllers that are still running 5x86's at 133MHz; about the same speed as a Pentium 75. > i586 is the original pentium, at 60, 66, 90, 100 up to about 133Mhz 233 is the fastest Pentium MMX I've seen. AMD's K5 and K6 series topped out at 500; they're all i586-class procs. AMD's Geode in same series. Cyrix and later VIA C3-series chips go faster, but are still i586-class chips (up to 1GHz or so, maybe faster). 800MHz embedded C3's have been very popular in the embedded space. And this class of chip is what many people would like to run C5 and C6 (and they are beefy enough to run text mode for either of these, really, since they would mostly be used as network devices with no local GUI). > really, we should have compiler targets for optimizing on the P4 > 'netburst' CPUs and another for the core processors as they are all > pipelined differently. Very very true. Netburst is very different from Pentium M and Core architectures. > as it turns out, however, the core 2 and core > I3/5/7 do pretty well with pentium-II and -III style optimization > strategies, as well as, of course, the x86_64 support. Has to do with Core being descended from Pentium M architecture, which is essentially souped-up Pentium III. The history of Pentium M is a fascinating study.