Alacrity and the GCD

[Kaedis]

I was under the impression Alacrity was effectively the same stat as WoW's Haste (except GCD interaction), which would seem to be 'activation speed'.

[Alratan]

Correct. 'Activation Time' == 'Cast Time'. See this post for more on Alacrity.

[LB_StorM]

Is the formula for the new casting time still assumed to be



or was this proven incorrect? I'm trying to make sense of what effect a 9% increase in Alacrity would have.

[Kaedis]

Storm, as far as I know, that's the formula we've been operating under the assumption of. At least, I've yet to hear otherwise.

[LB_StorM]

(11-21-2011 08:53 PM)Kore Wrote:  Storm, as far as I know, that's the formula we've been operating under the assumption of. At least, I've yet to hear otherwise.

Great, thanks! Last thing I need to know is, we have confirmation that an increase in Alacrity doesn't affect the GCD, right? Or are we still in the dark for that one?

[LB_StorM]

This is the word from two testers at Alterswtor

Quote:I would say that given the GCD is the speed at which instant cast abilities 'lightup' again when I used a + 75 alacrity relic it seemed to me they lit up faster, ergo alacrity affects the GCD

Quote:Alacrity rating does indeed impact the GCD now. Further testing is taking place in an attempt to approximate the coefficients.

Has anyone tested this? We have been working under the opposite assumption, that alacrity does not affect the GCD.

[Aleatha]

I have been testing this with my 116 Alacrity Agent, and didn't noticed any change in GCD lightup effect.

Aside from that, after some quick calculations my guess is that Alacrity's hard cap is roughly 25%.

Given the 4% coming from Talents, 21% are needed from stuff/buffs.

But I'll let you pro theorycrafters confirm this (or not )

Thanks for the formula list, and sorry for any english mistake.

[LagunaD]

(12-05-2011 06:55 AM)LB_StorM Wrote:  This is the word from two testers at Alterswtor

Quote:I would say that given the GCD is the speed at which instant cast abilities 'lightup' again when I used a + 75 alacrity relic it seemed to me they lit up faster, ergo alacrity affects the GCD

Quote:Alacrity rating does indeed impact the GCD now. Further testing is taking place in an attempt to approximate the coefficients.

Has anyone tested this? We have been working under the opposite assumption, that alacrity does not affect the GCD.

The largest effect that +75 Alacrity could have is 6.2%. If it did lower the GCD, it would change from 1.5s to 1.5/(1+0.062) = 1.41s, a difference of 0.09s.

I have a very hard time believing that would be noticeable. I just tested with a +90 Alacrity adrenal on a Level 22 character, which will give a slightly bigger effect than the largest haste +75 could give, and while there is no evidence of it affecting the GCD, a 0.09s difference is at the limit of what I can measure using video capture and single-stepping through the frames...

I am trying now to do a test with a larger value of Alacrity, which should either confirm or rule out any effect on the GCD.

BTW, there is no cap on the Alacrity percentage, but there is a cap on the bonus from Alacrity Rating, which is 30%. Any bonus expressed as a percentage rather than a rating would not be counted against the cap.

[Kaedis]

The easiest way to test it is to find a buff that is on the GCD but has no CD, and can be cast out of combat (if one even exists). If you can't find one, you should be able to substitute using the out-of-combat channel, if you interrupt it instantly. Cast it 20-30 times, timing how long it takes from start to finish. Do it again without any gear one. At 6.2% haste, the difference will be 2.7 seconds at 30 casts if it affects the GCD. You could up it to 60 casts if you want (don't lose count!) and push the difference to 6 seconds, essentially completely beyond the error bars even using a simple stopwatch.

Alternatively, measure 75 seconds worth of casting, and count how many you cast in it. With no Alacrity, you'll have 50 GCDs. At 6.2%, you should have 53.

[LagunaD]

OK, so I tested with a +150 Alacrity Rating adrenal on my 22 Sorc. This gives 10.29% Alacrity, at least 50% more than a +75 relic could possibly give. If the GCD were affected, it would go down to 1.5/(1+0.1029) = 1.36 seconds

Using FRAPS to capture video and stepping through it frame by frame, the GCDs with and without the adrenal are the identical (and equal to 1.5s).