Re: Accelerator //e

[supertimer@aol.com (Supertimer)]

spec@vax2.concordia.ca (Mitchell Spector) wrote:

>In article pubpc1@library.ucla.edu writes...
>
>>Mitchell Spector wrote:
>>
>>>     Probably, but your still dealing with the limitations of the
>>> 65C816 processor (even an ancient 386SX does math better, and in
>>> a lot of cases a 286 or 8086) and the bus speed of the C64/C128.
>>
>>(1) When running my Zip GS set to 10Mhz, it runs everything, math
>>    or not, faster than my PC Transporter (equivalent to a 186
>>    10Mhz).
>
>    Are you sure about that? I recall several people mentioning
>they were able to decompress ZIP archives faster through the
>PC Transporter running MS-DOS unzippers, than with PMPUnZip.
>The NEC V30, incidentally, is more similar to the 8086 than
>the 80186.

Since I have an XT and a GS, I thought I would help settle this
debate.

Experiment time!  The 8086 XT is older than the GS, so comparisons
are fair game.  I dusted off my Turbo XT, which has a genuine
Intel 8086 going at 8Mhz.  It has no math chip.  The XT is packed
with 640K of RAM and has an MFM hard disk.  In the other corner,
I have the accelerator on the GS set to 8Mhz.  GS has an SCSI
hard disk and 4MB of RAM.  Let the games begin!

First test: decode a JPEG file.

The GS used a GS/OS JPEG decoder while the XT used JPG2GIF, a
DOS JPEG decoder.  And they're off...both computers take forever
to do their thing.  The winner is...the GS.  Part of the blame
can be attributed to the XT having to use disk caching to get around
the 640K limitation and running up against the slow MFM hard disk
access, but I think the GS processor is genuinely faster than the
8086 in this task.

Test 2: unpack a .zip archive

The GS used Angel, an 8-bit decoder but considerably faster
than PMPunzip.  The XT used pkZip's official .zip unpacker.
And they're off.  The winner is again the GS.  This time, the
XT has no excuse.  It has 640K of RAM while Angel is using
just the 128K that it is accessing in IIe mode (even though
the GS actually has 4MB).

I conclude from these tests that the 65816 is faster than the
8086 when running at the same speed in terms of Mhz.  It is,
in my opinion, most comparable to the 286.

Does the PC Transporter use the additional memory of the GS
as extended memory?  Does the PC Transporter have a math chip?
If these two conditions are true and the PC Transporter has
access to the faster SCSI drive of the GS, then that emulator
may be faster than a regular Turbo XT.  I remember AE's claim
that the PC Transporter was faster than a regular XT, but am
skeptical that it was significantly faster than a real
Turbo XT.  I can't believe that it would make much of a
difference in the above tests.

>    I think Supertimer made a very good point in response to 
>this very message thread. At least I think so, since I like
>the GS in its own rights and for the fun of pushing it beyond
>what it was originally designed to do (in both software and
>hardware). Not trying to compare it directly against 486's
>and Pentiums; if I were to do that there would be little 
>reason for me to hold my interest in it. I accept and can
>acknowledge all its limitations, but it doesn't mean I hold
>any less interest in the machine.

For sure it would be pointless to compare it to a Pentium.
That is a modern computer compared to the GS, a classic
computer.  I agree with you that the 65816 can't match a 486
in terms of math.  Why, the above tests would be
instantaneous on a Pentium or PowerPC. I do not agree with you
taking that fact and concluding that the 65816 is slower than
an 8086 or 286, however.  Those computers are also classics
today and comparing a classic to a classic is fair game.
Clearly, the 65816 is faster than an 8086 and more comparable
to a 286--in tasks like drawing and running a CGA or Hercules
desktop for GEM, even an unaccelerated GS is even able to
match a 286 AT with more Mhz.  486 is another story.

I think you and Scott are missing each others' points.  You
are saying that a 486 is a faster processor than the 65816.
He is saying that GS software runs faster on GS hardware than
PC software runs on a 486.  You are both right--while the
486 is faster than a 65816, its software has also grown more
complex (and slower).  On the surface, it would seem like
many programs are faster on the GS.  Someone else said that
modern programmers don't bother writing fast software--they
write slow software and wait for the hardware to get faster.
I think that is an accurate assessment and it is the reason
I stick to DOS WordPerfect on the PC and AppleWorks on
the GS.