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Re: Re: Linux tracking software for Linux



On Fri, Dec 07, 2001 at 07:00:57PM -0500, Margaret Leber wrote:
> 
> A Palm is not particularly underpowered, and the performance of the 
> current J2ME implementation might surpise you. 

I haven't designed anything that slow into any embedded computer
system in the past 10 years.  Yes from my perspective, it is very
slow, akin to a Mac Classic II.  Java on even 68040 Macs was
pretty much of a dog.
 
> I run SatTrack against a list of 40 some satellites on a 900MHz PII, 
> and it literally doesn't even notice the CPU load. I can't imagine that 
> tracking *one* sat at a time on a Dragonball at 20 or 30 MHz--even in 
> Java--is that big a deal.  

>From memory, I believe a 16 MHz 68000 processor ran less than 1400
Dhyrstones. I believe you will find the processing power difference
handling floating point arithmetic is at least 500 times that
of a 16 MHz 68000 that is only capable of integer math. Then you
burden it with Java bytecode compiler that has a miserable efficiency
compared to pure C code and your expected 40X difference isn't even
close.

If you want some other benchmark results, take a look at the
distributed.net website, with various computers running the RC5-64
challenge.  There is at least a 30X (real, measured data) between
my Mac Quadra 800 (68040, 32 MHz) and my Athlon TBird 933 MHz system.  
The Quadra's 68040 processor is several times faster than a 68000
at the same clock speed.

The venerable 68K processor has been a real workhorse for the past
two decades that it has existed, but it is certainly showing its
age these days...

73 Mike W4LNA
 

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