How to get 80 Mflops from your SUN 4/110 for $10K. Summary.

[Omar A. Karim]

My original posting is included below:

|I have this SUN 4/110 with 8 MB memory, 140 Mb disk, 60 Mb Tape drive and
|19 in Mono monitor. It runs at about 0.8 Megaflops, 7 MIPS.  I want to
|UPGRADE this if possible, but SUN wants an arm and a head for any possible
|upgrade. They clearly would much rather I buy a whole new system, such as
|a SPARC 2. I would like an improved performance of 8-10 Megaflops, while
|retaining all the peripherals.  I have $7000 or so to spend. Have I stated
|my woeful and perhaps common case clearly enough?

The responses are included below, and I would like to convey my thanks to
all who responded. Unfortunately none of the responses were what I had
hoped for....

My own investigation into this led to two possible products: One called a
SKYBOLT, from SKY computers, which is an add-on, like an FPA, and
supposedly would deliver 40 MIPS (integer) and 60 Mflops with their
special vectorizing compilers. Cost is around $10K.  Anyone interested can
contact SKY at (508) 256-1626. I am looking into such a purchase. 

The other add-on is caled a SPARCplug. It costs $20K and is therefore not
of much use to me at the present time. Delivers lots of MIPS and MF, I
don't have the exact numbers handy.

Omar A. Karim
Department of Physics
UNC-Wilmington

RESPONSES:

***

I can relate...  but 8-10 Mflops?  I don't think you'll get that from Sun.
Maybe you should look into a bottom-of-the-line IBM RS6000.  Academic
prices last time i checked were under $10K.   Not the same compilers/OS,
though...  but that thing sure screams for number crunching.

Well, if it's Mflops you want, check out how you're compiling your code.
Suns tend to have a lot of magic incantations that can make a difference;
you should try the -O2 and -O3 opt levels, and use the inline libraries.
also, i find that linking -Bstatic is usually good for some performance,
occasionally a lot.   The sun compilers are kind of stupid;  I would
strongly recommend that you profile your applications ( compile and link
with -p flag, run a job, then "prof executable_file > prof.out")   This
usually turns up some interesting things.   I find that a bit of code
hacking is usually worth it with Sun compilers, because they just don't
seem to make some obvious optimizations.   Unrolling short inner loops,
using scalar temps for sums instead of subscripted variables, and
replacing the "**" exponentiation operator (if you use fortran) with
multiplies will all help.   Also, I find integer math to really stink on
my sparcstation 1.  Floating point is far faster.   This is all based on
my experiences with an SS1.   I suspect it would mostly apply to a 4/110
as well.  With the exception of the strange slowness of integer math, all
this stuff will help on pretty much any machine.   Of course, if you don't
have source code, you'll just have to buy a faster machine that maintains
binary compatibility...  You also might consider a SparcStation SLC.  They
list for only $3K, i think, and it seems like you should be able to use
your peripherals with one.   No 8-10 MFLOPS there, though.  about 3 tops
would be my estimate.  

*** 

Even the 4/20 outperforms the 4/110. For your money you could make the
4/20 into a server and run the 4/110 diskless. Just going from 8MB to 16MB
would be a big win.  

*** 

8 to 10 Megaflops from Sun?  I have not seen such a product from them yet.
The SPARC 2 is rated at 4.8 Mflop.  Good Luck.