NEB calculation with gpu

[Mukesh]

Hi,
I am trying to do NEB calculation with vtst tool. After running some calculations, I came to know that in neb calculation each image runs simultaneously and on a different node (card in GPU). My code vasp is working fine with vtst too. But my cluster has only four 4 card on X-cray computer. But when I want to have 5 images, it will run only four folder ie 01, 02, 03, 04, and not 05. Is there any way to do this calculation by using GPU with let's say 1 or 2 cards (Since I can't use all the cards every time).

On X-cray: I use command like this for one card-

aprun -n 1 -N 1 -d 18 path/to/vasp_gpu

thanks and regards
Mukes Singh

[graeme]

Hi Mukes,
As far as I know, each GPU should have one mpi rank. So while you can split a vasp calculation over several GPUs, you will not be able to have 5 mpi ranks share 4 GPUs.
Graeme

[Mukesh]

thanks a lot for replying quickly. Is there any way I can do these calculations?
I am thinking, let's say I run each calculation going into each folder, I mean, I go into 00, 01, 02, 03, 04, 05 directory and put POTCAR, KPOINTS and INCAR with some changes? if Yes what am I supposed to change in INCAR?

thanks and regards
Mukesh Singh

[graeme]

Why is it so important to run the NEB with 5 images; why don't you run it with 4?