How many plants could I grow in a 3'x3'x6.5' tent with 600w HPS?

I was wondering what would be a good amount of plants to grow in this sizes tent and maintain nice sized plants and yields?

1 large or 4 medium or 9 small or 12 tiny. Or a comparable combination.

This is a 4x4 tent of which ~3x3 is usable due to side lighting. This is 6 plants - 2 medium and 4 small. Aim to yield .5 - 1lb per grow.