Gaming HTPC first build - INET. Please help (på svenska or english)!

Hi! and Welcome,

Well for
1)
a) i have no clue to that but i guess i should work
b) as long as all clocking options are set to auto it should be energy-efficient, mostly so it could clock down when idling
2)
a) Light gaming should be no problem, most-bang-for-the buck and energy-efficient would be the 6670 but it is to weak for gaming so try the 6870, it uses 58 watts less then the 6950 under full load and differs around 10 fps in crysis on ultra settings
b) for htpc use the stock cooler will be enough, but more intense gaming and cpu work might make the stock coolers fan noisy

3)
a) sorry but i see no use in overclocking an allready powerfull cpu as the i5 2500k
b) sure you can, depending on what kind of tv tuner card you choose but the motherboard have 3 pci-e ports so wouldn't be a problem

Asking in english is okey by my opinion as it is an international language

You can choose Vengeance Low profile memory or Ripjaws memory in order to eliminate comptibility problems with tower coolers.
Then Noctue NH-14D, Noctua NH-U12P, Scythe Ninja 3 or Scythe Mugen 2 can be used as CPU cooler. All are very effective (and big) coolers, that can cool an i5 2500K easily, even with the fans set at low rpm.
The noctua coolers include good fans that are low noise when the included ULNA adapters are used (the voltage to the fan is decreased by the ULNA adapter). The scythe coolers have reasonably silent fans, but I would buy adapters to lower the voltage to the fans to 7V http://www.inet.se/artikel/6308178/motstand-flakt-zalman12v-7... (similar as ULNA).

I would not use the default Intel cooler as I think it's too loud under load.

When it comes to videocards, I'd opt for a card with Asus Direct CU cooler or Gigabyte's non reference cooler. HD6850/HD6870/HD6950 or GTX460/GTX560Ti would be what I would choose, since they offer a decent tradeoff between power consumption and computing power. I'd lean more towards the HD68xx cards AMD cards though, as they offer a lower power consumption.

I'd skip out on the CF/SLI option though as the big coolers on the more silent cards are far from optimal for SLI/CF use, and the reference models are too noisy. Then there is the temperature issue with two rather power-hungry cards in a case with low RPM-fans aimed for silence rather than ventilation.

The Gentle Typhoon fans are a good choice, nice airflow but pretty silent. You might consider a fan controller, that way you can finetune the rpm of the fans to an optimal balance between sound and cooling.

As for the question if your system is energy-efficient enough to serve as a HTPC-system, i'd agree with Joovel. The system is energy efficient enough considering that it probably will be in idle or sleep-mode most of the time (if you configure the sleep mode and make sure speedstep is active).