the prayer drain multiplier is (30 + prayer bonus)/30 the multiplier is multiplied by the prayer's base drain rate (as given in seconds per prayer point drop) to give the modified prayer drain. - at a prayer bonus of 0, turmoil will drain at 1800 prayer points per hour - at a prayer bonus of 9 (fury, full bandos, fire cape), turmoil will drain at 1385 prayer points per hour - at a prayer bonus of 19 (fury, full bandos, SW cape), turmoil will drain at 1102 prayer points per hour - at a prayer bonus of 30 (fury, full proselyte, SW cape), turmoil will drain at 900 prayer points per hour as you can see, the more prayer bonus you already have, the less benefit that more prayer bonus will give you. the first 9 prayer bonus reduced prayer drain by 415 points, but the next 10 prayer bonus only reduced prayer drain by 283 prayer points and the next 11 prayer bonus only reduced prayer drain by 202 points. conversely, strength bonus gives nearly constant returns, regardless of what your strength bonus already is. that's why switching your proselyte for bandos (if you have the money for the armor) is not that bad - you keep a high prayer bonus (19), but get the benefit of more strength. if you have high enough prayer and summoning levels so that healing and inventory space are not an issue, then you can switch to full bandos and fire cape to maximize kill speeds - prayer potions are cheap enough currently that the extra slayer xp, charms, and drops from your increased kill speeds will more than compensate the 2.5 prayer potions per hour that proselyte or soulwars cape save.