It's not a question of need. Graphics are an embarrassingly parallel problem so any additional shader pipelines or processing units of any sort can be immediately utilized for additional performance.
It isn't like CPUs where half of the cores will languish until the user opens 20 more tabs in Google Chrome.
It isn't like CPUs where half of the cores will languish until the user opens 20 more tabs in Google Chrome.
Are you saying 640k should be enough for anybody?