Close

Benchmarks!

A project log for rosco_m68k

A full-featured Motorola 68k retro computer, starring a 68010 running at 8MHz

Ross BamfordRoss Bamford 06/13/2020 at 19:411 Comment

Over on Discord, @Xark recently did some work on porting some old dhrystones to the rosco_m68k, which gave a feel for the performance of the board for the first time, and the results are encouraging! In Xark's words, we "blew the doors off an outdated Dhrystone text file found somewhere on the Internet" :D

Obviously these are to be taken with a hefty grain of salt as they're hardly "fair" - we're using a much more modern compiler than was likely available for any of the other machines on the list, and we also don't have an OS to get in the way. To try and make it a more even fight we did limit the GCC optimisation to -O1, which feels like it should be roughly on-par with the optimisations that would have been done by the compilers in use at the the time the other machines were benchmarked. 

To see how the rosco_m68k stacked up against other machines of the same era, we ran the benchmarks with both 8MHz and 10MHz system clock. The results were thus (further down the list is better):

Last updated 06/06/2020 by Xark
*----------------DHRYSTONE VERSION 1.1 RESULTS BEGIN--------------------------
 *
 * MACHINE      MICROPROCESSOR  OPERATING       COMPILER        DHRYSTONES/SEC.
 * TYPE                         SYSTEM                          NO REG  REGS
 * --------------------------   ------------    -----------     ---------------
 * Apple IIe    65C02-1.02Mhz   DOS 3.3         Aztec CII v1.05i  37      37
 * -            Z80-2.5Mhz      CPM-80 v2.2     Aztec CII v1.05g  91      91
 * -            8086-8Mhz       RMX86 V6        Intel C-86 V2.0  197     203LM??
 * IBM PC/XT    8088-4.77Mhz    COHERENT 2.3.43 Mark Wiiliams    259     275
 * -            8086-8Mhz       RMX86 V6        Intel C-86 V2.0  287     304 ??
 * Fortune 32:16 68000-6Mhz     V7+sys3+4.1BSD  cc               360     346
 * PDP-11/34A   w/FP-11C        UNIX V7m        cc               406     449
 * Macintosh512 68000-7.7Mhz    Mac ROM O/S     DeSmet(C ware)   625     625
 * VAX-11/750   w/FPA           UNIX 4.2BSD     cc               831     852
 * rosco_m68k   68010-8.0Mhz    ROM             gcc-7.5.0        -       862 (-O1)
 * DataMedia 932 68000-10Mhz    UNIX sysV       cc               837     888
 * Plexus P35   68000-12.5Mhz   UNIX sysIII     cc               835     894
 * ATT PC7300   68010-10Mhz     UNIX 5.0.3      cc               973    1034
 * rosco_m68k   68010-10Mhz     ROM             gcc-7.5.0        -      1086 (-O1)
 * Compaq II    80286-8Mhz      MSDOS 3.1       MS C 3.0        1086    1140 LM
 * IBM PC/AT    80286-7.5Mhz    Venix/286 SVR2  cc              1159    1254 *15
 * Compaq II    80286-8Mhz      MSDOS 3.1       MS C 3.0        1190    1282 MM
 * MicroVAX II  -               Mach/4.3        cc              1361    1385
 * DEC uVAX II  -               Ultrix-32m v1.1 cc              1385    1399
 * Compaq II    80286-8Mhz      MSDOS 3.1       MS C 3.0        1351    1428
 * VAX 11/780   -               UNIX 4.2BSD     cc              1417    1441
 * VAX-780/MA780                Mach/4.3        cc              1428    1470
 * VAX 11/780   -               UNIX 5.0.1      cc 4.1.1.31     1650    1640
 * Ridge 32C V1 -               ROS 3.3         Ridge C (older) 1628    1695
 * Gould PN6005 -               UTX 1.1c+ (4.2) cc              1732    1884
 * Gould PN9080 custom ECL      UTX-32 1.1C     cc              4745    4992
 * VAX-784      -               Mach/4.3        cc              5263    5555 &4
 * VAX 8600     -               4.3 BSD         cc              6329    6423
 * Amdahl 5860  -               UTS sysV        cc 1.22        28735   28846
 * IBM3090/200  -               ?               ?              31250   31250
 *

It was really exciting to see these results - the rosco_m68k is the fastest 68000 in both the 8MHz and 10MHz categories :) 

I will say again that the lack of an OS at the moment is probably a distinct advantage here, although these results were captured with the system timer tick running which does some memory access a couple hundred times a second and toggles a GPIO periodically, so it's not like there was nothing else going on - I like to think the results are in some way representative.

You can find the code along with the results in a text file here.

Discussions

henk.gooijen wrote 06/17/2020 at 17:11 point

That is fun to see!
I have a VAX-11/750 (and I have the FPA board, but it double-functions as a heater, so that board is not installed). Cool to see that the 68010 ROSCO is next to the VAX in performance :)

  Are you sure? yes | no