The Truth About Quartz

Mortigan the Lock had a post about increasing DPS without gear/stat upgrades where he advocated hitting the next cast button early. He was summarily trolled to death about the quartz addon, and how it makes the job easy for you. I figured I'd lay out some information on how it actually works, and some things even long-time users may not know about this addon.

It all goes back to a long time ago when spell casters couldn't be hit capped and the mechanics of the blizzard server were more harsh. Back then, the only way you could start your spell was if the other one was finished. However, because of the lag between client and server, the normal player would have anywhere between 100-200 ms of lag time, thus injecting an extra 100-200 ms of no casting. Ultimately, this reduced the effectiveness of casting classes for dps and even if you mashed the buttons, channeled spells could get messed up (I played an SPriest in BC, so I know all about clipping mind flays).

So Quartz was the addon you would use, and it would show you the lag between the server and your computer via a nice red bar, seen below. This was an amazing tool to minimize the dead zone between casts, since you'd simply hit your spell at red zone. Therefore, this was a required mod for most raiding groups.

Come patch 3.0.3 (pre-Wrath patch), Blizzard implemented spell queuing. Spell queuing works by allowing a player to cast a spell slightly before it casts (my guess is about 250 ms) and it would immediately start that spell upon finishing the current cast. This was great, because it helped alleviate the gap between low and high ping casters, as they all could theoretically chain casts without any dead zone (assuming low ping variability). Hooray!

However, a lot of Quartz users have not adjusted their play to utilize spell queuing. Since you can now cast your spells early, here's a protip, free of cost.

Quartz users should be hitting the next spell BEFORE the red zone on non-channeled spells.
If you're still waiting for red, you're not going to be casting back-to-back spells.

In summary, Quartz is still an amazing addon that increases DPS, but the way you use the addon has changed since BC. Nibb High Football Rules!