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From: wayne@helix.nih.gov (Wayne Rasband)
Newsgroups: comp.sys.mac.hardware
Subject: Re: LC Prediction (Was: New Macintosh Strategy)
Message-ID: <598@nih-csl.nih.gov>
Date: 2 Nov 90 22:25:22 GMT
References: <9037@ncar.ucar.edu>
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In article <9037@ncar.ucar.edu> hpoppe@ncar.ucar.edu (Herb Poppe) writes:
> Although the LC has a 68020 running at 16MHz (as does the Mac II), it is 
> configured with a 16-bit data path to memory instead of the 32-bit data 
> path of the Mac II. Since two bus cycles are required to read 32-bits 
> from memory on the LC (where only one bus cycle is required on the Mac II), 
> the LC is only half as fast as the Mac II, all other things being equal.

The LC isn't as slow as you might expect. I  run some benchmarks on it the 
other day, and, due to its built-in video,  it actually out performed the 
Mac II on a few graphics intensive benchmarks.  The 16-bit data path does 
make the LC somewhat slower for CPU intensive tasks, but notice how It 
runs small integer benchmarks, such as the Sieve, as fast as the Mac II. 
This is probably because the code fits entirely inside the 68020's tiny 
256 byte instruction cash. It is clear from these results that you 
wouldn't want to do number crunching on the LC without adding a third 
party FPU.


Radius Benchmark V1.0b6

               SE        LC      Mac II    Mac IIfx

Float        44.7         10        0.5        .2
Trig          452         86          1        .3
Butterfly     149         29        7.6       1.6
Ripples      1095        238       27.4         9
Sieve        41.4        8.8        8.5       3.1
Moire          28        8.2       13.2       3.8        
Circles      25.7         19         21      17.5
Arcs         15.8        9.8        10.9        8


Speedometer 2.5

                 SE       LC      Mac II     Mac IIfx

Whetstones       7.2     35.6      51.5        199
Dhrystones       916     2104      2982      11321
Sieve           34.2      7.9       7.9        2.3
Savage           395       70      47.3       11.8

CPU              .99     3.23      3.39       12.4
Math             .98     4.76      6.72       26.2


"Sharpen" filter in Image(pixels/sec)

                 SE        LC      Mac II    Mac IIfx

                 NA        57K      60K        172K