Normal temp range for QX6850?

[iamsostupid]

as i was saying, the power dissipation can be generalized by P = CV^2F

where P is power, C is capacitance, V is voltage and F is the frequency.

taking examples from measurements of other kentsfields online, i've found an average C to be 0.02382 from this and your quoted voltage and freq i have approximated your power dissipation at 183.5989623 watts. compare this to a stock Q6600 at 102w full load.

with an ultra 120 extreme and lots of airflow, you should be expecting to idle in the mid to low 40s and load in the 50s, so i would get a good fan and reapply the correct amount of grease. i recommend arctic silver 5. you could certainly drop 15C with an optimized setup. if you haven't already, i would try flirting with lower voltages, and testing for stability issues. if you could run on 1.4 you'd have shaved off 12 watts. if you can run 1.35 you'd have saved 25w. it's worth looking into. even then, in a rather lucky low voltage environment, you'd be at roughly 160w under full load, which is a ton. more than a Presler at 3466Mhz. so you also need to consider some adjustments to your airflow situation.

I would consider buying a pair of either Panaflo FBA12G12L1BX (30dbA) or pair of Scythe SFF21E (20dbA). The panaflos will move 40% more air for 50% more noise. both fans are $15 apiece. you have an awesome case, and i would consider the scythe fans for the most of the 120mm mounts in your case. and perhaps one for the side door.

if your configuration were worst-case, you could certainly be subject to idling in the high 50's and loading in the low 80's. kentsfields at stock speeds do this 24/7 with the retail cooler.