I’ve played frost mage since 5.2 and my dps is 105k-125k (iLvl 510). But than I heard that if I have enough crit I should respec fire. Is this right? Or what is the best spec at the moment for mages in PvE?
currently there isn’t a ”go to” spec for all mages. With a low ilvl the best spec is frost, but, as you improve you gear, fire tends to scale a lot better. Arcane, which theoretically is very strong, isn’t viable due to its totally lack of mobility (there are some exceptions, like ra den if you wear 4 heroic tier pieces).
With your gear I suggest you to play frost, and switch to fire when you can reach 12k crit (buffed). For a minor dps improvement you should change your t5 talent to living bomb for single target and nether tempest for cleave (frost bomb is better only when there are 6+ mobs). You can also change some gem/reforge -askmrrobot is a very powerful tool-.
That’s all I guess, I hope I helped you :)