On Tue, 09 Feb 2016 15:51:54 +0100, Peter Graf wrote: > Am 09.02.2016 14:14, schrieb Thierry Godefroy: > > On Tue, 09 Feb 2016 10:36:02 +0100, Peter Graf wrote: > > > >> Am 08.02.2016 21:19, schrieb Thierry Godefroy: > >>> > >>> Q60 @ 66MHz (overclocked 68060RC50): > >>> 127.82 BogoMips > >>> Writethrough cache mode: 24.937 VAX Mips/43813.5 Dhrystones/s (5M runs) > >>> Copyback cache mode: 47.812 VAX Mips/84005.4 Dhrystones/s (5M runs) > >> > >> A 68060 with fully activated caches should deliver (almost) exactly > >> twice the clock frequency in BogoMIPS. And for my machines, it did, at > >> least under Linux. > > > > The memory cache mode (write back or write through) is irrelevant for > > BogoMips since no data is written to the memory during the timing loop: > > only the pipeline and execution units number count, and the 68060 indeed > > can execute two simple instructions per clock. > > As you wrote below, there is a little interrupt overhead, so it's better > if they are on copyback.
Not really, because the interrupt routines don't write that much to the memory either... The problem with the copy back mode on the Q60, is that it crashes all QLiberated programs, so... > That probably explains it. I must have seen it under Linux as suspected. > But even there I got only 159.8 BogoMIPS when I retried under Linux. > 157.9 under QDOS Classic. The Linux boot-time bogomips benchmark happens very early in the kernel initialization process, long before device drivers, interrupts and kernels daemons are started, so it's normal that you got almost no overhead at all. > Can not work on my Q60 anymore since my CRT Monitor just died. That's one of my fears: I've got one CRT left: when it will die, the Q60 will become unusable since, alas, I could not get any modern monitor or even any rescaler board/box (Jamma board & Co) to sync its video signal... It would be great if we could get a 800x600 Q60 GLUE chip to replace the 1024x512 one (not more video memory needed, and full SGVA compatibility). Thierry. _______________________________________________ QL-Users Mailing List
