I can't find an option in enhsim to sync potion of speed with heroism (like it does for trinkets) to test out when is the best time to use it on dps burn phases. I have been using during heroism but wanted to test.

First time poster... I'm going to take a stab at Saabu's question here... I'm not sure this is really the correct place for the question, but if my answer is accurate, that's probably the reason why the Potion of Speed option described isn't implemented in EnhSim.



I've been operating under the assumption that it really doesn't matter when you use a Potion of Speed. No matter what your current haste level is, 500 extra haste rating will always net the same amount of extra weapon swings.

Here's some math copied and pasted from my guild's forum... Some of it may seem out of context since it's pulled from a larger post about haste and its effects.





THE MATH
For this explanation, I will introduce a new metric: "Extra Swings per Minute," denoted ESM. It is equal to 60((1/WSf)-(1/WSi)) and can be interpreted as the amount of extra white melee attack you will receive per minute when going from WSi (Initial Weapon Speed) to WSf (Final Weapon Speed).

On the surface, Haste seems very bland and predictable. This is not the case. It also seems intuitive to say "10% Haste will reduce my swing speed by 10%." This is also not true for all values. Here is a quick example:

Assume 2.60 Weapon Speed. Ten percent of 2.60 is 0.260. So, does 10% Haste drop the swing speed to 2.60-0.26 = 2.34? Nope. Using the haste equation: 2.6/(1+0.1) = 2.364, a reduction of 0.236, not 0.260.

Ok, so now for the linear claim.

Assume again we are working with a 2.60 speed weapon. As shown above, 10% haste reduces the swing speed by 0.236 seconds.

Now assume we have 20% haste, rather than 10%. Swing speed is brought to 2.167, a reduction of 0.433. So, using 10%, for each 1% haste we reduced our swing speed by 0.236/10 = .0236. At 20% haste, for each 1% we reduced our swing speed by 0.433/20 = .0216.

As you can see, it seems that the haste at the 10% level has given us .0236-.0216 = .002 more benefit for each 1%. As you can imagine, even with these small numbers, the gap gets larger for larger values of haste.

So, were the first 10% actually "better" than the next 10%? No.

Applying the ESM treatment, we see that:

10% Level
ESM = 60((1/2.364)-(1/2.60))
ESM@10 = 4.2857

20% Level
ESM = 60((1/2.167)-(1/2.60))
ESM@20 = 8.5714

So, we normalize both:
(ESM@10)/10 = 0.42857
(ESM@20)/20 = 0.42857

At both the 10% Haste level and the 20% Haste level, each % of Haste yields the same amount of extra swings per minute.


So, even though we saw a smaller reduction in swing speed at the 20% level than at the 10% level, which suggest haste gets "worse" as you get more, we can see that is not the case. Haste will always yield the same amount of extra swings per minute, regardless of how much you have.






Ok, so if the above math is correct (which I think it is), an extra 500 haste rating will cause you to gain the same amount of white melee swings inside and outside of the effects of Heroism/Bloodlust. If you have some other "on use" types of things that would add value to white melee attacks, such as AP or ArP trinkets that you use during Heroism/Bloodlust, the Potion of Speed would be better to use when those other effects are active.

If boss-specific issues like amount of time spent attacking from behind, in movement, stunned, casting hex or wind shear*, or other non-dps time are considered, what about other boss-specific issues? Most encounters provide buffs or debuffs that radically affect damage. The sim as currently implemented works well in part because it ignores all of these factors. A sim or model that includes settings for every factor involved in every current-tier boss fight would certainly be an upgrade, but that seems like significant added work.

As a side note, even the best sim can't account for some factors. If a run speed enchant helps me run out of a damaging effect faster, it's valuable for reasons aside from increasing dps time.

* I know wind shear isn't on gcd or shock cd, but it takes personal reaction time to incorporate.