Open Steam client.
Open library and choose Ark.
Right-click and open Properties.
In the General tab, select Set Launch Options.
In the command line type following lines with spacing:

-useallavailablecores – Makes your PC use all available CPU cores.

-high -Sets game as a high priority process.

-sm4 – Runs DX10 shader model.

-d3d10 – Runs DX10 mode.

-nomansky – Lowers in-game sky quality.

-lowmemory – Optimizes the game for 4GB RAM

Save your selection and run the game.