Compiling VASP 4.6.26 with g95 for Opteron box

Message

Mahesh_chandran · #1 Post by **Mahesh_chandran** » Fri Aug 26, 2005 9:08 am

Hi,
We are planning to compile parallel VASP 4.6 for Opteron boxes using g95 fortran compiler (http://www.g95.org/). Has anyone tried this before ? If yes, please let me know if there
was any compile time problems faced and the solution to it.

thanks

regards
Mahesh

j.meyer · #2 Post by **j.meyer** » Mon Sep 05, 2005 8:58 am

Hello Mahesh,

I have successfully compiled VASP using the g95 compiler.
However, the current version from http://www.g95.org/ (2005-09-04)
no longer seems to be able to compile VASP as I have just tested quickly:
/home/jm/tmp/g95-install/bin/g95 -O0 -ffree-form -c diolib.f
In file diolib.f:12

IMPLICIT REAL(q) (A-H,O-Z)
1
Error: Letter 'Q' already set in IMPLICIT statement at (1)
make: *** [diolib.o] Fehler 1
Maybe it is possible to circumvent this error by using special
compiler options. But I do not have the time to play around with
that at the moment.
The g95 that compilation worked with was from 2005-06-05 I think.
Nevertheless I had to use -O0 to avoid runtime errors and so
performance of this version is quite bad. Using the Intel Fortran
compiler I have can build an executable that runs almost twice as fast
on my AthlonXP.
I have done some more testing concerning the influence of compilers
and libraries on VASP performance. Maybe I will post them here soon.

Regards,
JÃ¶rg Meyer