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cluster:175 [2018/09/26 12:35] hmeij07 [Lammps] |
cluster:175 [2018/09/26 20:23] hmeij07 [What to Buy] |
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| 1 K20 | 6 | 47 | x4 | 188 | | | 1 K20 | 6 | 47 | x4 | 188 | | ||
- | That means the P100 works as well as the GTX. The K20 works at 50% the performance level of the others | + | That means the P100 works as well as the GTX. The K20 works at 50% the performance level of the others |
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</ | </ | ||
+ | |||
+ | ==== Gromacs 2018.3 ==== | ||
+ | |||
+ | The multidir not running in Gromacs 2018 is a bug in the code clashing with the call MPI_Barrier (communication timing error). | ||
+ | |||
+ | < | ||
+ | |||
+ | # multidir -gpu_id 0123 with four simultaneous gromacs processes | ||
+ | |||
+ | -np 8 -ntomp | ||
+ | 01/ | ||
+ | 02/ | ||
+ | 03/ | ||
+ | 04/ | ||
+ | |||
+ | -np 16 -ntomp | ||
+ | 01/ | ||
+ | 02/ | ||
+ | 03/ | ||
+ | 04/ | ||
+ | |||
+ | multidir -gpu_id 00112233 with eight simultaneous gromacs processes | ||
+ | sharing the gpus, 2 processes per gpu | ||
+ | |||
+ | -np 8 -ntomp | ||
+ | Error in user input: | ||
+ | The string of available GPU device IDs ' | ||
+ | device IDs | ||
+ | |||
+ | </ | ||
+ | |||
+ | That last error when loading multiple processes per gpu is *not* according to their documentation. So the multidir performance is similar to previous single dir performance but still lags GTX performance by quite a bit. Albeit, there is room in utilization rate of the gpus. | ||
+ | |||
==== What to Buy ==== | ==== What to Buy ==== | ||
* Amber folks: does not matter | * Amber folks: does not matter | ||
- | * Lammps folks: P100 nodes please | + | * Lammps folks: P100 nodes please, although in hybrid runs does not matter |
* Gromacs folks: GTX nodes please | * Gromacs folks: GTX nodes please | ||