You need 2032 Group DPS (1.280.000 HP in 630 seconds). On our first clear we were at:

PLD - 165 - ilvl 110 weapon
WAR - 165 - ilvl 110 weapon
WHM - 10
SCH - 40
MNK - 425 - ilvl 110 weapon
BRD - 370 - ilvl 115 weapon
SMN - 360 - ilvl 115 weapon
DRG - 410 - ilvl 110 weapon
Limit Break - 150 (1 Caster LB3 + 1 Melee LB1)

= 2095

Sure, not top of the hill, but enough to beat it. DPS comes with practice, the more you are accommodated to the mechanics the more DPS you'll have