I am seeing the same thing, as the poster you replied to. Just really sad DPS for a Frost DK at ilvl 500. I can barely do 75k in LFR. I am 2h, obviously doing PVE, and of course 25m LFR. I can post a log if it's required, but I use a LOT of TuanHA's other CRs so I know a class this high up on the dps chart can be doing a lot better.
At any rate, I have the following talents: Rolling Blood, Purgatory, Asphyxiate, Death Pact, Blood Tap, Remorseless Winter. I am using the following glyphs: Dark Succor, Anti-Magic Shell, and Icebound Fortitude. I'm following AskMrRobot for reforge, gemming, and enchants.
On the dummy, I can sometimes burst to 95k, but sustained after 10mil is still only around 78-79k. I have all features I don't use in a raid or are very situational like Chains of Ice, Death Grip, etc turned off on the CR to ease up processing, and I am using Tyrael at 60FPS and Framelock. It seems to be running smoothly and consistently, just not putting up the numbers I would expect.
Oh, and it won't put down Death and Decay until it's almost too late. Not sure what it's waiting for, but is there a way to make it put Death and Decay down first before doing Outbreak, Pestilence, etc? The mobs are almost always 2/3 - 3/4 of the way dead before the CR puts Death and Decay down, rendering it almost useless and really hurting my AoE dps. Not that anyone really cares in LFR, but I'm doing LFR to get geared for Flex and Reg, so yea. Thanks in advance!