You need to increase the value of the virtual memory file. The total memory capacity of all video cards plus the amount of RAM memory
Is this true?
On my ubuntu 17.10 machine with 32GB physical memory I just have a 16GB swap partition and have a GTX1060 3GB plus on-board Quadro M1200 4GB so going by your reckoning I should set swap size to be 40GB ?
I'll try adding another swap file sized 24GB and see if there is any difference in performance.