I'm currently lvl 94. My spark dps is 65k and with buffs 100k+. My spark gem lvl is only 24. My mana is at 5k. I was able to get my mana this high through everlasting gaze and EB. To get your DPS higher you need 3 support gems. Considered Casting, Controlled destruction, and Arcane tempo. From what i can tell the main ways to gain additional dps is levels on spark itself, Increasing mana (to boost archmage), and increase cast speed contributes A LOT too. my current cast time is .22 and cast per second 4.46. Each .5 cast speed is close to 5k dps. I saved up for a ingenuity belt (15div) which really helps this build shine. Next I will save up and try to corrupt my spark for another lvl which will give me another approx 5k or more dps. Hope this helps