🚀 go-pugleaf

#R:rna:-27100:uiucuxc:25800010:000:1820
uiucuxc!beaucham    Jul 26 22:18:00 1984

   We are about to buy an LMC after months of soul searching.  While not the
fastest machine in the world, it does do very well on fairly long floating
point intensive programs, particularly in C, but also in F77, and F.P. was our
most important requirement.  (there is an unfortunate initial overhead with F77
--the entire library is loaded whether you need it or not!)  We have bench 
marked it against the Dual 83/80, the Integrated Solutions 5/10, the PDP11/34,
the IBM CS9000, and the VAX 11/780, both for compile and execution times on 
three C and four F77 programs. (the Dual and I.S. machines use the 68000 and
68010, respectively, with no FPU in our tests; also, the VAX had no FPA.)
   
The results show that the LMC is about 9 times slower than the VAX on compiles,
with a variation from 6 to 12,  and 6 times slower than the VAX on executions,
varying from 2.3 to 12.  However, the poor executions were for short F77
programs. For two fpu-intensive C jobs and one fpu-intensive long F77 job the 
LMC averaged only x3 slower than the VAX, and we are talking about a $22,500
machine!  ($16875 with educational discount) 

These benchmarks were done under the Unity operating system with the 6 MHz
clock.  Switching to the Genix op. sys. soon is supposed to increase system
speed twofold and an increase of clock speed to 8 MHz soon is supposed to
improve performance by much more than a linear increase.  Also, they have
9 track tape working and will soon have an intelligent RS232 interface.
  
While we were disappointed with the LMC compared to the 68k machines in terms
of the edit/compile/ex debug cycle for short programs, our need for good F.P.
for the buck for long programs was the deciding factor in our chooosing the LMC.
If anyone is interested in the benchmark details, I can provide those too.