Lower the framerate (set the max to less than 50, higher than 10 because it would like really choppy), turn down the biome blend (preferably to like 0), TURN DOWN THE RENDER DISTANCE (it helps a ton)
If it still lags, then turn off fancy graphics, turn off clouds, and set particles to 'minimal'
I have a windows 10, (not sure what specs, I honestly don't care though), and it lagged a ton with default settings, but when you turn down the graphics settings the game runs so much soother