Re: [ccp4bb]: CCP4 - Pentium - Again

[Graeme Winter <graeme@mrc-lmb.cam.ac.uk>]

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Hi All,

> Some people prefer SuSE (to name but one) but I doubt any flavour of Linux
> will help the speed of the programs running.
> The biggest speedup for programs running on Linux is to have them compiled
> with the Intel compilers (I think these are only available for RedHat?).
> There is no standard setup support for Intel compilers in CCP4 as yet, but
> it is possible to compile CCP4 4.2.1 as described in Clemen's web pages
>

Although these only come as RPM's (the intel compilers) they will work on
SuSE/Mandrake/... as well as redhat - and probably any linux which will
support rpms. We use the intel compilers here on SuSE.

>
> you may just want to check that they [the intel compilers] do only work on
> redhat. they
> certainly only came as RPMs (redhat package manager) last I looked. the
> speed inclrease for some programs is reportedly >20percent. The current
> version of beast compiled with intel doesnt work but I have some fixes to
> try for that as well...
>

Depending on what you're doing, you can in very rare circumstances get
extremely good speed improvements using the intel compiler - I have had as
much as a factor of 2.5 in execution speed between gcc 2.95.3 and icc 6 -
however, I have heard that gcc3.1 will give similar speed improvements in
these situations.

Lastly, for anyone buying (pc based) computer systems, I expect that the
type of memory that you use will have a more significant impact on
performance than the clock speed of the CPU. Might be worth thinking about
at least DDR (double data rate) or RAMBUS, especially if you're using
2GHz+ processors.

Cheers,

Graeme