[gmx-users] progressive imbalance in REMD

[David van der Spoel]

On 2012-04-13 17:46, francesco oteri wrote:
> Dear gromacs users,
> I am running REMD through gromacs 4.5.5 using 10replicas.
> I am experiencing a problem with simulation efficiency, in particular
> from gromacs output, like the following:
> vol 0.49  imb F  4% vol 0.64  imb F  8% vol 0.17  imb F  2% vol 0.56
>   imb F 10% vol 0.17! imb F  7% vol 0.75  imb F 11% vol 0.45  imb F 11%
> vol 0.13! imb F  8% vol 0.45  imb F 16% vol 0.55  imb F 23% step 735900,
> will finish Mon Apr 16 07:29:53 2012
>
> it seems that higher temperature replicas suffer of an higher imbalance
> between force and PME.
>
>
> These are the average values:
>
> 4.58991117815
> 5.5175129881
> 6.32679738562
> 7.21887045416
> 8.1979219038
> 9.45466733702
> 10.9115133233
> 12.5899111781
> 15.0987095693
> 19.5630970337
>
> Of course this problem impacts on overall performances.
>
> My questions are:
> 1) Is the progressive imbalance expected?
Yes, due to lower density.

> 2) Is there any way to alleviate the problem?
No.

>
>
> Francesco
>
>


-- 
David van der Spoel, Ph.D., Professor of Biology
Dept. of Cell & Molec. Biol., Uppsala University.
Box 596, 75124 Uppsala, Sweden. Phone:	+46184714205.
spoel at xray.bmc.uu.se    http://folding.bmc.uu.se