As I've been leveling my shadow priest I've begun to notice that I need to stop and drink more often between fights. Going up through the late 20's and 30's I could take out five or six mobs before stopping to drink, but once I hit 40 and moved on to Tanaris and Feralas my mob kill count dropped to two or three before having to drink.
My normal spell rotation is PW:S, Mind Blast, SW:P, Mind Flay, Mind Flay, Mind Blast (if needed) and wand to death. My mana is at 3553 right now and I've got +54 bonus damage (if that matters). I did spec into Focused Mind to try and reduce some mana costs.
So my question is, is it normal to go OOM after two or three mobs at this level? I see other caster classes running around and killing a lot more before having to drink. Or is it because my mana is too low? I've been stacking +int and +spi gear (mostly "of the Owl" stuff) but should I try for more? Or is this just a normal thing at this level?
Overall I love playing my priest as it's a very different and pleasant change of pace from playing my warrior.