Friday, May 09, 2008

A 2-cycle Example

Perhaps an example will help illustrate the difference between 2-cycle DPS and normal DPS.

You are a caster with 1000 mana. The next fight is 90 seconds long. You have the following two spells:

Burn Spell - 1.5s cast, 500 damage, 100 mana cost
Efficient Spell - 1.5s cast, 100 damage, 10 mana cost

What combination of spells produces the maximum damage?

Rather than actually using an algorithm, we'll just list out all the possibilities:

The most damage comes when you cast 4 Burn spells and 56 Efficient spells. Now let's make a slight change, and add 20 mana to your mana pool, for a total of 1020 mana.

This time, maximum damage comes from casting 5 Burn spells and only 52 Efficient spells. You even spend 4.5s doing nothing! The extra mana, a Longevity stat, allows you to do more damage by spending more time in burn mode. Note that this system is also very sensitive to fight length. If the fight was longer or shorter, that would have produced a different result. You could also increase damage by adding DPS stats, making each individual spell hit a bit harder.

Now, contrast this system to the process used by my Destruction (Shadow) Warlock. I don't have two spells, I only have Shadow Bolt. Adding 20 mana doesn't really do a whole lot. I spend all of my time and effort making my Shadow Bolt hit harder (spell damage, crit rating) and more often (hit rating, haste). Longevity stats are far less useful than DPS stats.

Of course, optimizing those DPS stats is pretty complex. But it's a completely different process than balancing Longevity and DPS stats.


  1. Destro locks use 1 spell, but a lot of DPS classes employ multiple attacks and have to feel out which combination nets them the best results. The example of Mutilate rogues comes to mind. Their skill cycles are pretty complex and dynamic, and require constant micro-management of their combo points versus the remaining durations of their Slice and Dice and Rupture finishers. They also must find the right balance of hit, AP, and crit on their gear to ensure that their attacks land, hit hard, and crit often for extra CP's. This example has ramifications on both gearing AND skill usage.

    Warlocks are a rough example when speaking of mana efficiency, because whatever they spend they can Life Tap back.

    Elemental Shaman who stack haste (which produces more DPS in t6 gear than stacking spell damage) do have a concern of going out of mana, and do have 2 cycle's to consider depending on gear level and fight length. I'd direct you to the Elemental Think Tank of EJ:

  2. You'll often hear people talk about how you need to "balance" stats on gear.

    They're absolutely 100% wrong.

    Gear is designed with a itemization budget. Given two pieces of gear with equal iLevel, the better piece of gear is always the one with the more 'efficient' stat selection - the one which maximizes those stats (such as spell hit and spell haste) which return more damage than others (such as Intellect).

    The issue of longevity is largely a red herring for dps casters because mp5 is normally very inefficient at producing additional damage and only works if you were going to run out of mana.

  3. Ok, so now I think I see what you're doing. In this example, you're comparing intellect to spell damage. But you don't finish the calculations. If 20 mana produces more damage in the second rotation, how much spell damage would the mage need to do more damage using the first rotation? In gear comparisons, 'longevity' stats are always taken into account but it is still usually more efficient to prioritise damage stats. Clearly, your mage would take 40 intellect over 5 spell damage. But would they take 10 intellect over 20 spell damage? Or 5 intellect over 10 crit?

  4. Actually, longevity can have an effect even on destro locks.

    For boss fights a DS-destro spec often does more damage with a sacrificed felhunter (mana regen) rather than a sacrificed succubus (increased shadow damage). It only makes sense when you realise that the GCD from lifetap is wrecking your dps.

    Morogrim was the first time I really saw this but since then I've noticed the advantage in many other fights.