I've read a lot on these forums and tried to synthesize my answers from everyone's comments (which are great, BTW) but ultimately I am going to need some specific advice.

I'm am currently putting together a home theater PC. I've starting with an i3-2100T on a ASRock H67M in a Lian Li PC-Q07 and I've ordered a pico PSU from electrodacus. I've measured 165mm of clearance for the heatsink. My ears are going to be almost exactly 2m from the computer. The use case for the computer is to sit idle most of the time, then once a day we will watch a Blu-Ray movie or stream Netflix for maybe two hours.

Maybe once in a blue moon I will run a transcoding job that will tax the CPU for a couple days, and I have no problem dealing with noise in those rare situations. But normally I want the computer to be silent.

I've been reading a bunch of the HSF reviews on this site but the test rig has a much hotter processor than mine. Of course, from that I can compare each of the HSFs to each other but I still don't know what this will mean for me. And the temperatures of the CPU don't mean much to me either, and since temperature regulation is the goal of the HSF I might as well start there.

So, what temperatures should I be designing for? I know that higher temperatures mean shorter lives for the components. Say I was designing my computer to last 4 years, what is a reasonable temperature to keep the components under? 40C, 50C, 60C, 70C? And should I be concerned with the max temperature under load, the sustained temperature under load, or the sustained temperature at idle?

Now, assuming that I can answer those questions, let's move on to the heatsink. My assumption is that at idle my i3-2100T (and the rest of the components) won't need much cooling, maybe just a heatsink to draw the heat away from the CPU and a slight breeze to circulate the air (from a large but very slow fan on the case). Put another way: There exists a heatsink without a fan that will allow my system's temperature to stabilize at a reasonable level while idle. Is this a fair assumption?

Another assumption I have is that there exists a heatsink with enough mass to slow the heat rise enough so that I will be able to watch a movie without reaching the temperature limits that I've decided on based on the expected life of the components. And that this heatsink will be able to dissipate the stored heat after returning to idle until we watch the next movie (let's call that 12 hours).

The other variable that I'm working with is that my motherboard will be mounted vertically in the PC-Q07 case, so I want to make sure that my heatsink isn't so heavy that it tears my motherboard apart.

Given all of that:

- Are my assumptions correct and will I be able to run my computer like this?
- What temperatures should I attempt to keep my CPU at while idle and under load?
- What heatsink should I buy? (I am considering the Arctic Cooling Freezer 7 Pro rev. 2 since it's large but not too heavy, inexpensive, and available from New Egg. A lot of the reviewed heatsinks aren't easily available as far as I can tell)
- What fan would best serve my purposes (i.e. creating a slight breeze very quietly)?

Does all of this seem reasonable?

You should be able to cool that CPU passively with a heatsink such as the Thermalright HR02 quite easily. Now assuming you don't have that budget (and I doubt it will fit in that case) then you might want to look at a 120MM tower heatsink. I have the Corsair A70 and it seems to be pretty solid for the $25 I paid for it. For you, I would recommend taking a look at the Corsair A50, it is cheaper and should cool perfectly well with a low RPM fan such as the Nexus Real Silent (perhaps undervolted)

Corsair A50: http://www.newegg.com/Product/Product.a ... 6835181012
Nexus RealSilent http://www.newegg.com/Product/Product.a ... -_-Product