[gmx-developers] Assembler loops on Itanium2 Montecito.

[Rafael R. Pappalardo]

> Hi Rafael,
>
>First - which Gromacs version are you running?
>
I am using VERSION 3.3.99_development_20080208.
Other CVS versions have the same problem.
Should I try with 3.3.2?

>We experienced something similar a while ago, but I think that was a  
>compiler bug I never resolved.

I have used GCC 4.1, GCC 3.4 and ICC 10.1 with the same results. I am not sure 
how the assembler is compiled. Could I change the compiler used to compile 
the assembler routines?

>
>For reference, ia64 isn't particularly fast compared to x86 since we  
>have assembly loops for both :-)

Do you have an idea about the penalty incurred on IA64 by not using assembly 
loops? I mean, it's worthwhile to try to solve the problem? I have something 
like 20 dual core Itanium2 and my boss will be a bit upset if I tell him that 
a normal PC outperform them.

>
>Cheers,
>
>Erik

Best regards, 

Rafael
-- 
Dr. Rafael R. Pappalardo
Dept. Physical Chemistry, Univ. de Sevilla (Spain)
e-mail: rafapa at us.es