So recently I started playing my mage again and respected to arcane as I gotten a trial spot in a guild. Now last night I had my first trial raid were I felt I was completely under-performing compared to others in the raid I couldn't really figure out what I was doing so wrong that it caused for me to do such low DPS. I also had been going over the Arcane mage thread here and on EJ most of the day as well.
Logs from last night - worldoflogs.com/reports/rt-rasumbmd2nhi0aqd/sum/damageDone/
Armory - us.battle.net/wow/en/character/thaurissan/Grozar/advanced
I'm kind of busy right now, but the first and foremost thing to do is get your haste over 3100. You get an extra NT tick and (duh) faster casts. Hopefully someone else will pop up in the thread and help you more. Cya later.
I did not look at tsulong log witch is the one you posted, as it can be a bit messy and rng. i instead took a look at protectors as its a stable fight.
The logs looks okay, only thing i can point out is a bit low NT uptime(82%) should be 90%. And maybe you could have gotten off one more arcane power.
I think it might be low gear compared to your raid.
First of all, you should get that 500int gem as fast as you can but you stated you just started so gonna take a week or two.
You should use the minor glyph of loose mana, as it double dip with alter time. There is really no use for brilliant mana gem, its just the slackers choice if you tend to forget making new ones between pulls. Instead i would choose Arcane explosion for extra range, it comes in really handy on many fights to reset timer on arcane stacks while moving. On fights with % bonus damage modifiers like elegon, windlord(hc), amber shaper etc. swap out blink with Arcane Power glyph.
Also from my own experience, mastery arcane only wins over haste arcane when you can get 8k+ mastery, and really at just 8k they were about even, i had something like 9.5k haste, but this is very individual but i would suggest you trying out arcane haste RoP, only fight it does work on is windlord were i would go frost or mastery arcane. spirit kings i would swap RoP with Invocation in haste build.