RAM

In GLiCID, the amount of RAM reserved for a job is proportional to the number of cores. Thus, If you need more RAM than the default, you need to ask for more cores, even If you do not use them.

Depending on the partition, the default amount of RAM per core is different. To see the current values, use : scontrol show partition and look for the field DefMemPerCPU.

The values at the time of writing are :

Partition RAM/core

standard

3.8Go

visu

7.8Go

gpu

7.8Go

bigmem

7.8Go

Examples

  1. Your job needs 4 CPUs, don’t care about the RAM on standard partition ⇒ You’ll have 3.8Go \* 4 cores = 15.2Go of RAM for the whole job

  2. Your job needs 4 CPUs, and need 40Go of RAM on standard partition ⇒ It won’t fit in the default 15.2Go cited above, so you need to ask at least 40Go / 3.8Go = 10.52 ⇒ 11 cores for your whole job, even if you really only use 4

  3. Your job does not need that many cores (ex, GPU computing) so you need only 1 core, but need 200Go of RAM on the gpu partition ⇒ You cannot ask for 1 core and 200Go RAM so, 200Go / 7.8Go = 25.64 ⇒ you need to ask at least 26 cores to fit everything