Hi, i was wondering. Do i need to put a fan, like mount it on the side of the Ultra-120 or it will keep cool by itself

it is recommended to have a 12cm fan. It is possible to have the heatsink by itself but it will get too hot....If i were you, i'd get a quite 12cm fan for it....

YES, you need a fan. Nothing fancy.

If you run at stock speeds, it would not hurt your system to go without. But once you start upgrading processors and overclocking. It would help to ad the extra fans to help remove the added heat.

IMO get a very high CFM Fan. Like a Silverstone 110 CFM 120mm fan (i chose this because it comes with a fan controller). With a fan controller so you can have varying degrees of cooling. If you want it quiet put it on very low. If you want it at like 25C then put it at max lol.

You can see it here http://www.newegg.com/Product/Prod [...] toreType=0

which Scythe S-Flex model should i get?

Doesn't really matter what model you get, so long as it meets the cfm and noise level that you can tolerate.

Most modern motherboards have a QFan option within the BIOS, that can regulate a PWM Fan to different speed settings base on temp. Just make sure your Scythe is a PWM, or else you'd have to get some third party fan controller to control the fan speed.

Is the Ultra 120 still the top ranked air cooler? Or have some of the newer competitors taken the crown away?

As of now I think there isn't much difference with TRUE And the new tower cooler. Fanboys will say TRUE, but they all perform near equal.

There is so much more to factor in determining cooling, especially with ambient temps, case design, fan choices, etc. IMO, Get what you can afford and what will fit best with your case.

The price of the Thermalright Ultra-120 eXtreme with a decent fan is about double that of some of the fairly highly ranked competitors. Is it worth the extra bucks?

Like I said, it's up to you, your budget, and what noise level are you comfortable with.

Given unlimited funds, I would take a TRUE Black and a noisy expensive hi cfm PWM fan.

I can only recommend this review to help you make a choice.
http://www.guru3d.com/article/heat [...] up-review/

Thanks for the link. That one seems to show the Noctua as the hot setup. The TRUE Black is $80 plus fan and that's getting almost into low end water cooled territory. Ouch.

Good air cooling is much better than cheap water cooling any day....

I would put a push pull system for the TRUE.

I am using a Scythe SFF21F (63 cfm) with my TRUE. It's cooling a Q6600 OC'd to 3.6 GHz in an Antec 900 case. It's oriented vertically to take advantage of the 20 cm fan on top. (Hot air wants to rise; why fight physics.) I am letting the motherboard control the fan.

The machine work on the base was not particularly good. I hand lapped to take out the machine marks and to even out an offcenter bulge. It also exposed the copper core.

Currently, the Xigmatek s1283 is attracting a lot of attention. Performance is very, very close to the TRUE. And it's about half the price of a TRUE and fan.

Yeah, that Xigmatek sounds like a nice unit. I'm not a wild OCer so it would probably do just fine for a 45nm part.