Javaed posted on August 17, 2009
Haste Rating can be a bit of a confusing stat for Shadow Priests. At first glance, it seems simple enough, if you have enough Haste Rating for 1% Haste, your spells are cast 1% faster. However, there are a ton of our spells that are instant casts. We have DoTs, and those don't really benefit from Haste at all. So many people seem to think that Haste is a worthless stat.
Well folks, it's not really all that bad a stat. It's just an odd stat, and one that requires a bit of careful management to benefit from properly. Follow on after the break to learn exactly what benefits we gain from stat, and how to take advantage of them.
1) Haste and Mind Flay
As you should know by now, Mind Flay is being cast as the lowest priority spell in our Priority Queue. In practical terms, we wind up casting this spell between Mind Blasts. This is actually our only spell which benefits fully from Haste, but due to the 5.5 second period in which we can use it we only see these benefits at specific intervals.
To fully understand the phenomenon, you must think in terms of getting enough haste for extra Mind Flay ticks between each Mind Blast. With no haste at all, Mind Flay is a 3 second long channeled spell, that deals damage in 3 second intervals. This means, that in 5.5 seconds, we have time to get 5 ticks of Mind Flay, and get halfway to the 6th tick. If we delayed the recast of Mind Blast inorder to get 6 full ticks though, we would have less DPS than if we'd cut the second Mind Flay short after it had ticked twice. Haste is helpful here, as it allows us to fit 6 seconds worth of activity into an amount of time lasting only 5.5 seconds.
Let's get some Raw Numbers here, since that's what you're really going to want:
| Number of Mind Flay Ticks |
Haste Percentage Required |
Haste Rating Required |
| 6 |
8.5% |
274 HR |
| 7 |
22% |
703 HR |
| 8 |
31.5% |
1025 HR |
| 9 |
39% |
1276 HR |
| 10 |
45% |
1476 HR |
| 11 |
50% |
1640 HR
|
So, those are the exact amounts of HR you'd need to get so many extra Mind Flay ticks into that 5.5 second period of time. This is assuming perfect conditions however, meaning that you're casting your spells with machine-like precision, and that you have 0 latency. Latency is the time that it takes for your commands to be transmitted to and processed by the server, so this actualy gives us a bit of a problem, where we need extra to account for this. I'm doing a bit of research into exactly how this would work out mathematically, but for now, just realize that you'll actually need a bit more haste to account for this problem, an extra 1% or so to be safe.
2) Haste Descreases the Global Cool Down
Every spell we cast activates a 1.5 second Global Cool Down period. This is a break before we can cast another spell. However, Haste decreases the GCD up to a maximum of .5 seconds, or a 1 second GCD at 50% haste. This is important, as all of our spells besides Mind Flay are eitehr instant cast or have a 1.5 second cast time, that just happens to match the GCD. Remember that we have an opening rotation that we go through to reach 5 stacks of Shadow Weaving in order to start doing the maximum possible damage. The fastest we can accomplsih this is opening rotation is in 6.5 seconds (3 instants or 1.5 second spells plus 2 Mind Flay ticks). Every % of Haste is useful in reducing this cast sequence.
We also have situations that occasionally crop up while DPSing, where we 1) Don't need to refresh a DoT, 2) Have already cast Mind Blast and 3) Don't have enought time to get 2 ticks of Mind Flay in before having to either refresh a DoT or cast Mind Blast. In these situations, we can wind up with breaks in our DPS that last between 1 second and 1.5 seconds, which is a lot of wasted time. In these situations, casting Shadow Word: Death is a DPS increase over getting just one tick of Mind Flay. I don't have exact modeling for ya'll (and don't expect it any time soon), but from what I've seen, these intervals become more common as we get more Haste. This is something that takes a lot of practice to notice and capitalize on, but it's a definate benefit.
3) Mind Sear Scales Perfectly with Haste
Admitedly, this is mostly useful on trash, but who doesn't love breaking 10k DPS on trash packs? There are though, a few boss fights where faster AOE is important. XT, Kologarn, Freya, and Mimiron all have phases in the fight where you'll be AOEing down large packs of extra enemies. During these phases, faster Mind Sears can give you massive DPS boosts.