I have summarized the responses below. -david paul
(1) Is Splus faster (on a PC) under Linux than under
Windows? I am specifically thinking of intensive
loops here, but would also solicit information
regarding how Splus stores information within
the Linux system vx. Windows.
Response #1: Not significantly different, AFAIK. Linux
has better process management than Windoze, so on Linux
the Splus/R process need not hog all the resources
in a single CPU system. -Andy Liaw
Response #2: Everything is always faster on Linux,
especially if you recompile the kernel for your specific
machine. I think Linux ships compiled for a 386,
but you can recompile for 486, Pentium class, etc.
-Bruce McCullough
(2) Can Splus under Linux take advantage of multiple
processors? I know there was some discussion on
the listserv earlier about multiple processors,
but I don't recall if the Linux OS was mentioned.
After being chastised for not looking in the archives, I
realized that there WAS such a thing as archives and searched
for answers to this question. It turns out that Splus cannot
take advantage of multiple processors, but does receive some
small benefit from running on a dual-processing machine since
it effectively gets its own processor. The best bet is to
increase the memory. However, my archive search yielded a
result that the folks at Bell Labs were (in 1998) working on
a multi-threaded version of Splus. There is a nice link to
a dissertation that focuses on this specific issue. Don't
print it when your co-workers are trying to print, though, as
it is 170 pages long.
(3) Is R capable of taking advantage of multiple processors
under either the Windows or Linux OS?
Response #1: Similar to Splus. Splus is linked with Intel
Math Kernel Library for fast linear algebra operations.
R can be compiled with ATLAS on both Linux and Windoze to achieve
similar effect. I have compiled R with Intel MKL on Linux, and I
do get both CPUs to work simultaneously, e.g., on matrix
multiplication (but not much else). There's also a rpvm package
for running R on clusters. -Andy Liaw
(4) How does R compare to Splus with regards to (1) above?
Response #1: R's for loop is *generally* faster and more memory
efficient than Splus. I believe the gap has narrowed with Splus
6. It also depends a whole lot on what actually gets done inside
the loop. R doesn't do *everything* faster than Splus. For some
tasks R is actually quite a bit slower than Splus. -Andy Liaw
Response #2: Personally I have started migrating to R under linux.
It has come down to useability rather than speed, although speed
is an issue. S+ under the linux is the complicated new stuff that
does not gel with the simplicity I desire. I have avoided that
since I bought it and tested it. I do not regard Splus or R as
particularly usable under windows. Having other unix functionality
sitting ready to go such as awk, perl, sed etc etc is the key for
large powerful analyses. Doing some of the donkey work outside R/S+
is useful in some cases and essential in others. That said my data
are often rather large, like 250M lines etc etc. -S.D. Byers
Response #3: I have done a number of my own comparisons of
Windows vs Linux. My setup is that I have two harddrives, one for
Linux and one for Windows. I have Linux and Windows versions of
SPlus, Mathematica, RATS, TSP, and Tex/LaTeX. I did this experiment
with Windows 95 and Red Hat 5.2 (so this was years ago): A couple
programs I have run on TSP (Time Series Processor, a package for
doing econometrics) with both Windows 2000 and Red Hat 7.1, and
Linux is almost twice as fast. -Bruce McCullough
|