Re: [berman@example.com: LINUX on Alpha info]

[turnbull@example.com (Stephen J. Turnbull)]

>>>>> Darren Cook <darren@example.com> writes:

   >enterprise environment.  Digital makes the Alpha processor which
   >is the world's fastest single-chip microprocessor and which
   >currently supports three 64-bit operating systems (Digital UNIX,
   >OpenVMS and Linux) as well as Windows NT.

   I wonder if the same system would give better performance under Linux
   (64bit) or Windows NT (32 bit)? 

Surely under Linux.  :-)  I'm not terribly impressed with Windows NT's 
speed, but I've never used it with its native NTFS, nor in serious
applications.  The cards bounce slower when you win Solitaire....  :-)

   Does 64 bit only give an advantage in certain types of applications, or does
   it do everything more quickly? Does a program just need to be recompiled, or
   would it need some rewriting?

Depends on the rest of your hardware.  Presumably using the whole bus
for file and video transfers speeds everything up, for example.  But I
would imagine that drivers for NT for Alpha do use the whole bus, it's
the internals of the OS that remain 32 bits.

Certainly it will do everything more quickly, but you won't notice it
on your wordprocessor.  There you're better spending money on RAM,
video, and hardware cache on your HDD adapter.  If you recompile the
kernel a lot (Craig, how often *do* you recompile the kernel?  It
takes me 20 minutes, but I can always find *work* to do in the slack
time) you'll notice, if you use large nonlinear maths, you'll notice.

Most programs will just need to be recompiled.  Programs that worry
about endianness, byte size, word size, and so on (bitmap graphics,
large numerical packages) will need to be tuned.  But programs like
that which are available on the net for GCC will surely have their
hardware dependencies conditioned on a -DCOMPILE_FOR_DEC_ALPHA
#define.  You're more likely to run into misconfigurations for Linux
(the Smail maintainers have been complaining about this for years).

-- 
                            Stephen J. Turnbull
Institute of Policy and Planning Sciences                    Yaseppochi-Gumi
University of Tsukuba                      http://turnbull.sk.tsukuba.ac.jp/
Tennodai 1-1-1, Tsukuba, 305 JAPAN                 turnbull@example.com