Quote Originally Posted by Gormogon View Post
The average rotation being

Fire 3 > Fire 1 > Fire 1 > Fire 1 > Fire 1 > Blizzard 3 > Thunder 3 > Fire 3 > Fire 1 > Fire 1 > Fire 1 > Fire 1 > Fire 1 > Blizzard 3 > Thunder 3 > Fire 3 > Fire 1

The portion I highlighted and underlined is our have downtime. That takes on average 6-8 seconds off our DPS. Per minute it doesn't look pretty since 14 seconds is a lot of time if we compare it to 60 seconds.
Shadowzanon broke down the thunder cast "if this then cast this" pretty well in the DPS forums. Gonna quote:

Quote Originally Posted by Shadowzanon View Post
If you need to cast thunder 1 instead you do so. There is no huge dps increase from using thunder 2 over1 just more convinience. Due to the fact we do have to move you just make sure you have enough mana to do the following.
If 398+ mana, Bliz 3, then thunder 2. (or just 400+ if you cannot compute fast enough
If 291 to 397 mana, Bliz 3, thunder 1. (300 to 400 to be safe)
if 290 mana to 185 mana, Bliz 3, bliz one then thunder 2. (290 to 190 to be safe)
if less than 184 mana, use any ether or take your chances on casting bliz3 waiting for mana to tick which is what you want to avoid then cast thunder 2, best save ethers if you ever bump this low.
Adapting to what you got > striving to get 251 mana and losing potential dps for convenience. You are better just getting a phantasia and going dunefolk lalafell if 251 is your goal then no gear will hold you back in groups with a scholar but that should not be something you should do. Point is we can be whatever and still preform our dps to the best of our skill. we cannot just sit back and follow our rotation to the core because if you do, you are potentially crippling your dps.
You can also sub in Bliz III, swiftcast, Thun III, Fire III and be right on timing wise to fill your mp and get back into the Fire 1 spam. But if you are hard casting T3 during the downtime, you are losing DPS regardless of how you slice it.