Quote: Original post by swiftcoder
However, a quick question. I installed 2x 120mm case fans, and not having purchased a fan controller, they are connected directly to the PSU, and thus run always at full throttle. While this keeps the case temperature within 2 degrees of the ambient temperature, it also sounds like a hovercraft.

My motherboard (Biostar T-series) has 2 optional fan headers, labeled 'north bridge fan header' and 'system fan header'. The documentation doesn't describe them beyond that (and the pin layout, of course), and I don't actually see any way to attach a fan to the north bridge.

So is the system fan header intended to run a case fan? And can the north bridge fan header be used in the same way?

Yes, the system fan header is intended to run a case fan. Your motherboard should spec out the maximum wattage or amperage, which you can check against the label on the fan. Some very high power fans can overload the motherboard fan headers, in which case you can use those fan pin to molex converters instead. You might be okay plugging in the case fan to the "system fan" header, but I'm not sure I'd attach a big 120mm fan to the header called "north bridge fan header" without checking to make sure you weren't going to overload it.

About the noise. Some motherboards have fan speed controllers built in, which allow you to ramp down the fan speed (they usually do pulse-width modulation). If not, you can buy fan controllers which have variable resistors in series to lower the voltage, or there are also connectors that have resistors wired in series. Another option is to buy a fan that is engineered to run at a slower speed. This latter type of fan is as quiet as a fan that has its fan speed ramped down, but usually moves more air than a conventional fan running at a lower speed. I've bought several Noctua fans that I really like, such as the one I linked there. You'll barely be able to hear it, and it moves as much air as my loud old Antec 120mm fan running full blast. It also comes with a one of those connectors with resistors wired in series that I mentioned earlier, in case you want to make it even quieter; or you could use it to make a fan you already have quieter.

Of course, after you make your case fans quieter, then you'll notice how loud your 4870's fan is... which you can solve with this SilenX video card fan. I have one on my 4850 and it's much quieter than the stock cooler. It cools about as well as the stock cooler.

By the way, I'm not affiliated with moddersmart.com or anything, I just bought my cooling stuff through them and like them.