[gmx-users] time effect of including PME calculation

[David]

On Sun, 2005-06-05 at 12:11 -0400, Kai Zhuang wrote:
> hi all,
> 
> I ran a system without PME and pressure coupling, 4 days or so.
> I am currently computing the exact same system with PME calculation
> and pressure coupling included, it's the 7th day now and i'm a little
> ansy as about when is it going to end and/or if i did something wrong.
> 
> how much is the generaly increase of run-time due to including PME?
A factor of 2-3, but here you change the pressure coupling. It is
therefore interesting to check the density in both simulations.

> 
> the mdp file addition is:
> 
> ;Electrostatic
> coulombtype	=	PME
> fourierspacing	=	0.10
> pme_order	=	6
> ewald_rtol	=	1e-5
> 
> ; Pressure coupling
> Pcoupl		=	berendsen
> Pcoupltype	=	isotropic
> tau-p		=	1.0
> compressibility	=	4.5e-5
> ref-p		=	1.0
> 
> all the rest i left the same as before.
>  
-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,          75124 Uppsala, Sweden
phone:  46 18 471 4205          fax: 46 18 511 755
spoel at xray.bmc.uu.se    spoel at gromacs.org   http://xray.bmc.uu.se/~spoel
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++