[gmx-developers] Re: threads are now ON by default

[Dinler Antunes]

We are using an i7 920 processor to run Gromacs-4.0.7 with openmpi-1.4.1. The
simulations run well using 4 threads (using "mpirun -np 4 mdrun...") but the
performance is worse when we use 6 or 8 threads. Looking for some way to improve
our performance we found out this forum and then started to try use threads
without openmpi. We compiled gromacs again and used the command line as
described here ("mdrun -nt 8..."), but the following error appears:

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Program mdrun, VERSION 4.0.7
Source code file: mdrun.c, line: 410

Fatal error:
GROMACS compiled without threads support - can only use one thread
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But in gromacs-4.0.7 threads are not supposed to be ON by default?