What lvl to Quad

[Atmas]

It's no contest.

Pillar of Frost:

At 51 (First lvl available)
755 damage per mob x 4 / 325 mana = 9.29 dpmana

Will actually go up to 800 damage per mob and 9.846 dpmana

Circle of Force:

At 34 (First lvl available)
202 damage per mob x 4 / 175 mana = 4.617 dpmana

Will go up to 216 damage per mob and 4.937 dpmana

Same cast, recast, and resist modifier.