its around 4k mark but then again i never use extra util generators due to how much lava thay use i use magmatics with tier 1/2 of both dynamo augments
it could prob run a speed 1 quarry at full speed as for speed 2 you need air bit more my speed 2 quarry is running on 5-6k rf/t and buffers aint filling
i think speed 2 is around 10k mark and speed 3 is around 21k mark for rf/t useage