mark@mips.COM (Mark G. Johnson) (07/12/90)
The June 1990 issue of _IEEE_Micro_ contains an article about the
Morotola 68040, written by some of its designers. The article agrees
with some of the advertising copy, saying "The sustained
performance level is 20 VAX-equivalent MIPS and 3 Mflops at a clock
speed of 25 MHz." (1st paragraph, 4th sentence).
Later in the article, Figure 2 is particularly interesting; its caption reads
"Processor performance relative to the 68020 versus cache size
(where the 68020 equals 1)."
For the cache sizes actually used in the 68040 (4Kbytes), the
performance plotted in Figure 2 [68040 normalized to 68020] is in
the range 3.6X to 4.3X, depending upon the workload. Most of the
benchmarks shown are at 4.1X.
So, the data and the claim that 68040==20VAXmips implies that the earlier
68020 has a "sustained performance level of 4.9 VAX-equivalent MIPS"
(4.9 = 20/4.1). Does anybody seriously believe this?
About the most impartial data I could find was for the Hewlett Packard
HP9000 model 370 machine. This uses a 68030 (not 68020) at 33 MHz (not
25 MHz) and achieves a geometric mean of 3.9 SPECmarks [ref. SPEC
newsletter v1#1]. It seems reasonable to suspect the 68020 is no
better than the 030 in performance {else who'd want the 030?}, so we
conclude that the 020's performance is, at most, 3.9 VAX-equivalent
MIPS. This makes the 68040 a 16 VAXmips machine (at most), not 20 VAXmips
as advertised.
Of course the best method would be to lay hands on an actual computer
system that uses the 68040 and benchmark it; presumably Motorola
and/or NeXT and/or HP will do this someday. Prediction: the SPECmark
will be significantly below 20.0.
Disclaimer: I'm biased. Check out the SPEC newsletter and the issue
of IEEE Micro to see if I've distorted the
facts. (I assert that I haven't)
--
-- Mark Johnson
MIPS Computer Systems, 930 E. Arques M/S 2-02, Sunnyvale, CA 94086
(408) 524-8308 mark@mips.com {or ...!decwrl!mips!mark}fox@VIXEN.NSCL.MSU.EDU (07/14/90)
In article <40088@mips.mips.COM>, mark@mips.COM (Mark G. Johnson) writes... >The June 1990 issue of _IEEE_Micro_ contains an article about the >Morotola 68040, written by some of its designers. The article agrees >with some of the advertising copy, saying "The sustained >performance level is 20 VAX-equivalent MIPS and 3 Mflops at a clock >speed of 25 MHz." (1st paragraph, 4th sentence). > >Later in the article, Figure 2 is particularly interesting; its caption reads > "Processor performance relative to the 68020 versus cache size > (where the 68020 equals 1)." > >For the cache sizes actually used in the 68040 (4Kbytes), the >performance plotted in Figure 2 [68040 normalized to 68020] is in >the range 3.6X to 4.3X, depending upon the workload. Most of the >benchmarks shown are at 4.1X. > >So, the data and the claim that 68040==20VAXmips implies that the earlier >68020 has a "sustained performance level of 4.9 VAX-equivalent MIPS" >(4.9 = 20/4.1). Does anybody seriously believe this? > >About the most impartial data I could find was for the Hewlett Packard >HP9000 model 370 machine. This uses a 68030 (not 68020) at 33 MHz (not >25 MHz) and achieves a geometric mean of 3.9 SPECmarks [ref. SPEC >newsletter v1#1]. It seems reasonable to suspect the 68020 is no >better than the 030 in performance {else who'd want the 030?}, so we >conclude that the 020's performance is, at most, 3.9 VAX-equivalent >MIPS. This makes the 68040 a 16 VAXmips machine (at most), not 20 VAXmips >as advertised. For much of the stuff we run, 16Mhz 68020 + 68881 runs at about .8 VAX mips. (Scientific technical applications). So it seems to me that 25Mhz could be no faster than 25/16 * .8 = 1.25 VAX mips. Ron Fox | FOX@MSUNSCL.BITNET | Where the name NSCL | FOX@CYCVAX.NSCL.MSU.EDU | goes on before Michigan State University | MSUHEP::CYCVAX::FOX | the quality East Lansing, MI 48824-1321 | | goes in. USA
rwallace@vax1.tcd.ie (07/16/90)
In article <1990Jul13.163849.4282@msuinfo.cl.msu.edu>, fox@VIXEN.NSCL.MSU.EDU writes: > > For much of the stuff we run, 16Mhz 68020 + 68881 runs at about .8 VAX > mips. (Scientific technical applications). So it seems to me that > 25Mhz could be no faster than 25/16 * .8 = 1.25 VAX mips. Sounds like either we don't agree on what VAX MIPS mean or there's something seriously wrong with your system or benchmarks. The 68000 at 8MHz is rated at about .8 MIPS. The 68020 at 16MHz should run about 3-4 MIPS (factor of 2 for the clock rate, factor of 2-3 for the better design). OK, processors run below rated performance with depressing frequency for reasons like not enough cache memory, badly written code etc. but by a factor of 4??? Are you sure you weren't running a benchmark that proves your compiler produces code that only runs 25% as fast as it should? Russell Wallace, Trinity College, Dublin rwallace@vax1.tcd.ie "To summarize the summary of the summary: people are a problem"
k2@charly.bl.physik.tu-muenchen.de (Klaus Steinberger) (07/16/90)
mark@mips.COM (Mark G. Johnson) writes: >So, the data and the claim that 68040==20VAXmips implies that the earlier >68020 has a "sustained performance level of 4.9 VAX-equivalent MIPS" >(4.9 = 20/4.1). Does anybody seriously believe this? I don't know which clock-rates are used in this test, but on 25 Mhz or 33 Mhz, I think it's possible, but only for Integer!!!!! >About the most impartial data I could find was for the Hewlett Packard >HP9000 model 370 machine. This uses a 68030 (not 68020) at 33 MHz (not >25 MHz) and achieves a geometric mean of 3.9 SPECmarks [ref. SPEC >newsletter v1#1]. It seems reasonable to suspect the 68020 is no >better than the 030 in performance {else who'd want the 030?}, so we >conclude that the 020's performance is, at most, 3.9 VAX-equivalent Don't mix up SPECmarks and MIPS, SPECmarks measures also the Floating point power. To our experience, the VAX 780 has nearly the same floating point speed than a 68881. (Most times the FP is even faster, due to better compilers) If the data from Motorola is correct, the '040 Floating Point will be more than a magnitude faster than the 68881. (3.5 Mflops Linpack compared to 0.1 Mflops). I don't have Linpack data for the HP9000/370, but a Tektronix4315 (w. 68882) is claimed to 0.17 Mflops. Linpack data for a Vax11/780 is .14 Mflops. I don't know if Motorola has used all Fortran, or coded BLAS for the Linpack, but this should make a difference of at most 30 %. >Of course the best method would be to lay hands on an actual computer >system that uses the 68040 and benchmark it; presumably Motorola That's really the best method. Sincerely, Klaus Steinberger Klaus Steinberger Beschleunigerlabor der TU und LMU Muenchen Phone: (+49 89)3209 4287 Hochschulgelaende, D-8046 Garching, West Germany BITNET: K2@DGABLG5P Internet: k2@charly.bl.physik.tu-muenchen.de
gerry@zds-ux.UUCP (Gerry Gleason) (07/16/90)
In article <40088@mips.mips.COM> mark@mips.COM (Mark G. Johnson) writes: >The June 1990 issue of _IEEE_Micro_ contains an article about the >Morotola 68040, written by some of its designers. The article agrees >with some of the advertising copy, saying "The sustained >performance level is 20 VAX-equivalent MIPS and 3 Mflops at a clock >speed of 25 MHz." (1st paragraph, 4th sentence). >Later in the article, Figure 2 is particularly interesting; its caption reads > "Processor performance relative to the 68020 versus cache size > (where the 68020 equals 1)." >For the cache sizes actually used in the 68040 (4Kbytes), the >performance plotted in Figure 2 [68040 normalized to 68020] is in >the range 3.6X to 4.3X, depending upon the workload. Most of the >benchmarks shown are at 4.1X. Aren't you mixing apples and oranges a bit here? The first statement quoting 20 VAX MIPS is stated without reference to any cache, and then you then pick from the table the data point for a 68040 without any external cache. You also need to know whether the 68020 they are normalizing against has no cache, some cache, or is a theoretical zero wait state configuration. I'm not sure that anything can be concluded from the information posted. Gerry Gleason
bartho@obs.unige.ch (PAUL BARTHOLDI, OBSERVATOIRE DE GENEVE) (07/17/90)
In article <6535.26a0e67f@vax1.tcd.ie>, rwallace@vax1.tcd.ie writes: > In article <1990Jul13.163849.4282@msuinfo.cl.msu.edu>, fox@VIXEN.NSCL.MSU.EDU writes: >> >> For much of the stuff we run, 16Mhz 68020 + 68881 runs at about .8 VAX >> mips. (Scientific technical applications). So it seems to me that >> 25Mhz could be no faster than 25/16 * .8 = 1.25 VAX mips. > > Sounds like either we don't agree on what VAX MIPS mean or there's something > seriously wrong with your system or benchmarks. The 68000 at 8MHz is rated at > about .8 MIPS. The 68020 at 16MHz should run about 3-4 MIPS (factor of 2 for > the clock rate, factor of 2-3 for the better design). OK, processors run below > rated performance with depressing frequency for reasons like not enough cache > memory, badly written code etc. but by a factor of 4??? Are you sure you > weren't running a benchmark that proves your compiler produces code that only > runs 25% as fast as it should? > > Russell Wallace, Trinity College, Dublin > rwallace@vax1.tcd.ie > "To summarize the summary of the summary: people are a problem" We have a vax 780 with FPA (== 1 MIPS) and sun 3/60 at 16 MHz with 68881, that is the same configuration as above. All my comparisions show the sun to be between .5 and .8 of the vax for pure computational tasks (no io). One exception, TeX runs about twice as fast on the sun ... why ? In all cases, I used optimization, with the fortran compiler and standard libraries (TeX is written in pascal or C), on real problems we have run on many other machines too. So Russells data are correct for me. Who has a 68020/68881 that runs 3-4 times faster than a 780 ? Paul Bartholdi, Geneva Observatory
mslater@cup.portal.com (Michael Z Slater) (07/17/90)
Speaking of 68040 performance, has anyone on the net actually seen one running? I'm trying to collect some data on the current status of the chip. Michael Slater, Microprocessor Report mslater@cup.portal.com 707/823-4004 fax: 707/823-0504
gerry@zds-ux.UUCP (Gerry Gleason) (07/18/90)
In article <713@obs.unige.ch> bartho@obs.unige.ch (PAUL BARTHOLDI, OBSERVATOIRE DE GENEVE) writes: >In article <6535.26a0e67f@vax1.tcd.ie>, rwallace@vax1.tcd.ie writes: >> In article <1990Jul13.163849.4282@msuinfo.cl.msu.edu>, fox@VIXEN.NSCL.MSU.EDU writes: >>> >>> For much of the stuff we run, 16Mhz 68020 + 68881 runs at about .8 VAX >>> mips. (Scientific technical applications). So it seems to me that >>> 25Mhz could be no faster than 25/16 * .8 = 1.25 VAX mips. >> Sounds like either we don't agree on what VAX MIPS mean or there's something >> seriously wrong with your system or benchmarks. The 68000 at 8MHz is rated at I'd go with confusion over what "MIPS" measures. >We have a vax 780 with FPA (== 1 MIPS) and sun 3/60 at 16 MHz with 68881, that >is the same configuration as above. All my comparisions show the sun to be >between .5 and .8 of the vax for pure computational tasks (no io). One MIPS is a measure of integer CPU performance, so I wonder why people are being so careful to tell us about the floating point hardware. If you want to talk floating point, the metric is MFLOPS, not MIPS. Gerry Gleason
aburto@marlin.NOSC.MIL (Alfred A. Aburto) (07/20/90)
In article <713@obs.unige.ch> bartho@obs.unige.ch (PAUL BARTHOLDI, OBSERVATOIRE DE GENEVE) writes: >In article <6535.26a0e67f@vax1.tcd.ie>, rwallace@vax1.tcd.ie writes: >> In article <1990Jul13.163849.4282@msuinfo.cl.msu.edu>, fox@VIXEN.NSCL.MSU.EDU writes: >>> >>> For much of the stuff we run, 16Mhz 68020 + 68881 runs at about .8 VAX >>> mips. (Scientific technical applications). So it seems to me that >>> 25Mhz could be no faster than 25/16 * .8 = 1.25 VAX mips. >> >> Sounds like either we don't agree on what VAX MIPS mean or there's something >> seriously wrong with your system or benchmarks. The 68000 at 8MHz is rated at >> about .8 MIPS. The 68020 at 16MHz should run about 3-4 MIPS (factor of 2 for >> the clock rate, factor of 2-3 for the better design). OK, processors run below >> rated performance with depressing frequency for reasons like not enough cache >> memory, badly written code etc. but by a factor of 4??? Are you sure you >> weren't running a benchmark that proves your compiler produces code that only >> runs 25% as fast as it should? >> >> Russell Wallace, Trinity College, Dublin >> rwallace@vax1.tcd.ie >> "To summarize the summary of the summary: people are a problem" > >We have a vax 780 with FPA (== 1 MIPS) and sun 3/60 at 16 MHz with 68881, that >is the same configuration as above. All my comparisions show the sun to be >between .5 and .8 of the vax for pure computational tasks (no io). One >exception, TeX runs about twice as fast on the sun ... why ? In all cases, >I used optimization, with the fortran compiler and standard libraries (TeX >is written in pascal or C), on real problems we have run on many other machines >too. So Russells data are correct for me. Who has a 68020/68881 that runs >3-4 times faster than a 780 ? > > Paul Bartholdi, Geneva Observatory ----------- I noticed in IBM advertisements that 1 MIPS relative to the VAX-11/780 was based upon the VAX-11/780 doing 1757 (?) Dhrystones/sec. This was Version 1.1 of the Dhrystone. I don't know what particular compiler or what degree of optimizations were used (ahem, just minor points of course :-)). One VAX-11/780 may be different from another too ... In any event IF we ASSUME the 1757 Dhrys/sec is accurate for a 1 MIPS VAX-11/780 reference then we can go on and derive other possibly equally meaningless numbers (based upon other compilers with various sorts of optimizations applied). Well, I know from personal measurements that the Amiga with 25 MHz 68030 and fast nibble mode dram (with burst mode on) can do about 8200 Dhrys/sec (this is Dhrystone V2.1 which is said to be less optimizable than version V1.1 :-), but otherwise it is the same benchmark). These results indicate that the 68030 at 25 MHz is a 8200/1757 = 4.6 MIPS machine. ------------ Actually 5 MIPS for the 25 MHz 68030 is not all that unreasonable. Afterall most 68030 instructions execute in 3 Clock Cycles (implies 8.3 MIPS peak operation). Also if one operates in "synchronous" mode then many instructions execute in 2 CC's (implies 12.5 MIPS peak performance). However if we could assume (there I go again) typically 5 CC's per 68030 instruction then this implies a 5 MIPS machine. This seems very reasonable to me, but I have no hard data to examine ..... Al Aburto aburto@marlin.nosc.mil
seanf@sco.COM (Sean Fagan) (07/24/90)
In article <382@zds-ux.UUCP> gerry@zds-ux.UUCP (Gerry Gleason) writes: >MIPS is a measure of integer CPU performance, so I wonder why people are >being so careful to tell us about the floating point hardware. If you want >to talk floating point, the metric is MFLOPS, not MIPS. MIPS :== Millions of Instructions Per Second. I don't see the word "integer" in any form anywhere in there, nor is it implied. There are some machines that can do some fp stuff faster than integer instructions; a marketing-type person might want to use those. (However, I know of no machine where a NOP is slower than an FP add 8-).) MFLOPS (Millions of FLoating-point Operations Per Second) is used because there is a large class of people who don't really *care* how many instructions the machine can execute per second, just how many fp adds and multiplies it can do per second. In a rather major class of computers (Cray, for example), this is not completely related to MIPS (well, it is, but it can be as much as 64 times as much as MIPS). As to why telling about the floating-point hardware: if I remember correctly, there were some instructions on a VAX that would work faster if you had the FPA, since the microcode would use it for some "integer" instructions. -- Sean Eric Fagan | "let's face it, finding yourself dead is one seanf@sco.COM | of life's more difficult moments." uunet!sco!seanf | -- Mark Leeper, reviewing _Ghost_ (408) 458-1422 | Any opinions expressed are my own, not my employers'.
stp@ethz.UUCP (Stephan Paschedag) (07/28/90)
In article <1990Jul24.123842.19663@sco.COM> seanf@sco.COM (Sean Fagan) writes: > >MIPS :== Millions of Instructions Per Second. > >I don't see the word "integer" in any form anywhere in there, nor is it >implied. > MIPS :== Missleading Indicator for Processor Speed ============================================================================== OS/2 & PS/2 : half an operating system for half a computer Stephan Paschedag stp@ethz.UUCP MPL AG, Zelgweg 12, CH-5405 Baden-Daettwil ..!mcvax!cernvax!chx400!ethz!stp ______________________________________________________________________________