The particle spawn rate should take the game setting into account, reducing the particles to maybe 50% and 10% respectively. Their simulation is quite performance intense as well, there's certainly room for improvement.

what particle?
barrel? sieve?

Any, but the sieve ones are the most problematic with their gravity collision checks.

Automatic sieve particles exist disable option.
Barrel particles is Ex Nihilo control...

Well the point of the option is obviously to only reduce them, besides being the one exposed to the user. You can easily implement it as mentioned above by adding e.g.:

if (worldObj.rand.nextInt(9) < 9 - Minecraft.getMinecraft().gameSettings.particleSetting * 4) return;

at the start of TileEntitySieveAutomatic.spawnFX.

I still can't find the option to disable the autosieve particles.... I have optifine installed and I can't disable them....