#Prod'ness of Multitask'
14 messages in this thread
'386 eh? You should check out the Benchmark example in the DL libs.
If you upgraded to a 68020 you'd have better than a 80386…one can only
imagine what the 68030 is like!
Try the '150WINDOWS.EXE' program, it might change your view of the
envelope on the maximum number of tasks that can be opened. (Only a simple
example though)
Thought it (your messages) was well said also…and said…and said…
<Grin>
Scott
Scott,
I think you replied to the wrong person….I think you wanted to talk
to Patmore not me.
Don
]Scott,
Thanks for the response. I haven't consulted the DLs yet – maybe you can
narrow down my investigative options by specifying which library the
comparitive bechmarks can be found (and maybe also the name of the file). I
guess my assertion of the power and superiority (apparent or real) of the Intel
'386, comes from ariticles written in various computer magazines about the
possibilities offered by this chip. I believe the Computer Shopper had an
ariticle in it: one, two or three months back, scoping the possibilities of the
application of powerful artificial intelligent programs on a machine utilising
this chip. AI machines have a reputation of requiring a lot of system power
navigating through tremendous amounts of memory, and requiring large amounts of
processing power. Byte's (magazine) special IBM issue described the many facets
of the chip: on board MMU; pipelining (I believe it entertains six pipelines);
the allowance of an 8086 environment running concurrently with the more
advanced environment – a product of the chip's own innovative architecture;
runs at 3.64 Million of Instructions Per second etc.
I must admit that despite this, I haven't made any real technical
comparisons between this chip and the 68020 or 68030. But I get the impression
that, and my instincts tell me, this new Intel chip is overall superior to
both. Of course I could be wrong, maybe you or someone else can give me
specific reference to the `benchmarks you were telling me about.
Regards.
P.D.
From what I've heard, the '386 is running at about 3 to 4 MIPS at 16 Mhz with
an average of about 4 clicks per instruction. This "seems" to be significantly
faster than the 68020 (don't know about the 68030 yet) as far as the
speed/instruction. You can however get 68020's at 25 Mhz while "I believe"
that the fastest '386 is 16 Mhz.
Anybody with any spec's or docs are welcome to U/L them. I've read that
document in the D/L also and I'm not positive it makes sense as the average
instruction time seems to be considerably faster for an 80386.
–> Todd
The benchmarks in DL11:BENCH.DOC are not all that valid because they are with
dynamic memory; you must compare the 80386 results with the uncached 68020
results. That makes them just about equal, at the same clock speed. I'd like
to see the same benchmarks with cache on both processors, because real-world
machines are either going to have cache or static memory. Anyway, the '386
>may< have faster instruction times (I don't know), but it suffers from less
registers and a much less symmetric instruction set. It may execute
instructions faster, but it's going to take more of them (and more memory
references, which >cost<) to get anything done. In any case, if the '386 and
the '020 are close, the 68030 will blow the doors off the '386. The 68881
already clobbers the 8087/80287, and the 68882 will be that much faster (2-4x,
actually). The 80387? Haven't seen any references to it at all, except that
'386 machine and add-in-board manufacturers are leaving a socket open for it…
– Bela
Bela– Gee, I thought I had you all educated about the 386 vs. 020 and then
you go say something like that! 🙂 If you remember from a while back, the
IEEE Micro article has both dynamic and static ram test results. When using
fast external memory there are no wait states and the effect is the same as an
external cache memory. With the fast static memory the 386 is still somewhat
slower for equal clocks. Substituting full speed 020's gives much more speed
yet. Finally, the 68030 is predicted to be 2x a 68020.
To summarize using the quicksort benchmark (the only real program in the list)
gives the following table showing speed normalized to the 80386 being 1.00. The
680×0 times are with cache enabled.
cpu speed static(45ns) dynamic(150ns)
80286 (16) 0.85 0.98
80386 (16) 1.00 1.00
68020 (16) 1.66 2.49
68020 (25) 2.59 3.90
68030 (25) 5.18 7.80 (predicted)
Besides being a year or 2 later than the 68020, the 80386 is also definitely
slower. Perhaps the 486 will catch up with the 68020.
I lost your address. If you let me know I'll definitely copy this stuff and
send it to you. Can't have you going around spreading these vicious rumors. 🙂
Tom
Thanks again Tom. I had forgotten that these had been posted before. I am
really getting tired of the sort of people that the IBM and clones seem to
gather. They don't seem to care about anything nut Locust 123 and when they
read an article on a '386, they just make the assumption that if IBM is going
with it that it must be best and fastest.
Regards, Larry.
If you want to fight off these claims, your only choice is to type in the
tables from that IEEE article and upload the works to DL11. <grin, but do it
anyway…> I remembered being convinced by data that was for static memory,
but when I looked in the DL, it wasn't there! I still have a nagging feeling
that the '386 can be cached better than just hanging no-wait-state static RAM
off the bus… but I am pretty well convinced that the 68020 beats the 80386.
However, it would be very wrong to draw any such conclusions from
DL11:BENCH.DOC alone. – Bela
Patmore,
They are in DL 11 as BENCH.DOC.
Don
Much obliged for your assistance again Don.
Regards.
P.D.
The 80386 is probably an OK chip, as far as Intel is concerned. They've
finally bagged the 64K limitations (probably the last serious MPU designer to
do so), and the on-chip MMU is nice. Its kind of missed on several things,
though, when compared to the 68020 and the 68030. The 68020 has a reasonably
large instruction cache on-chip. An on-chip cache will always out-perform an
external cache, both from a cost point of view and from a "free external bus
time" point of view. The 68030 extends this design with a (presumably) better
instruction cache organization, a DATA cache as well, burst mode accesses to
nybble-mode DRAM, and an on-chip MMU. The on-chip caches are a big win, since
things happen internally, a cache miss doesn't slow anything down. This is not
true of many external cache designs. Now, while you might argue that the
on-chip MMU can offer the same advantages, that's not always that much of a
concern. The only thing that really slows you down with MMU translations is in
a virtual memory situation, in which logically addressed memory is not part of
physically addressed memory. In either case, the physical memory must be
restored from slow storage. External MMUs in a 68020 system are capable of
completing translation in time for no wait state memory accesses. The main
advantages of the on-chip MMU are (1) cost effectiveness, and (2) that creates
an MMU standard for the processor you're using. Of course, a poorly designed
on-chip MMU is a big loss. -Dave
All,
I will concede to the fact that I had read whatever articles I did, in the
context of a 'closed IBM frame of thinking'; i.e. the discussions of articles
concerning applications with the '386, and the technical specifications of the
chip, were done without comparison to a competitive microprocessor, and with
the implications of using that mpu in the same situation as the same subject
chip. My major influence to the idea of the
'386's superiority over the 68020 and even 68030, was determined by an article
in Byte magazine's IBM special issue, page 89, which simply describes the
subject chip (the '386), as being one of fascinating achievement; its technical
superiority over previous Intel mpu's; a comparison between the power of this
chip and a mainframe frame system (an IBM incidentally); comparative benchmarks
between a system using this chip (running at 16Mhz) and the Vax-11/780 –
Interestingly, the '386 shows a 72% increase in perforamance in executing the
Dhrystones over its competitor, and in the October issue of Computer Shopper, a
14.28 Mhz 68020 turbo Amiga does a 50% outperformance over the same Vax-11/780
– Taking for granted that 14.28 is approx 11% slower than 16, this and other
factors, should have indicated some suspicion of the fact that the 68020 and
the '386 might at least be somewhat competitive if not only in this area of
testing (the Dhrystones), but overall. NB. These comparisons of times are quite
very vague and do not premise to provide a real case of one chip against the
other: they just indicate a suspicion.
(contiued……)
The benchmarks in file Bench.doc does indeed provide some indication that
the 68020, cached or uncached, is competitive with the '386 to the extent that
the tables reveal. I will however be quick to point out there was uncertainty
in my assertions of the Intel chip over the Motorola's, but I am glad to say
that I believe the 68020 (and definetly the 68030) is probably the better of
the two.
You have all won a soul.