Verdict: Quiet, but very expensive.

We've seen the NH-U12F before, although back then it was known as the NH-U12. The addition of the 'F' means that it's supplied with a fan, although Socket AM2 support has been added too.

The Noctua's 120mm fan has a resistor cable that forces the fan to spin at 800rpm or 1,200rpm, both of which are respectably quiet. Due to the Noctua's weight, the HSF has to be screwed through the motherboard for both Socket AM2 and LGA775 PCs. This is rather annoying, but it means that it can be positioned facing the right direction, with the fan exhausting air out of the case, regardless of whether the CPU socket is aligned vertically or horizontally.

Installed in a Core 2 Quad system, the NH-U12F managed to keep the CPU 1ûC cooler than the reference Intel HSF at low fan speed, and 4ûC cooler at high fan speed. In our Athlon 64 X2 test rig, the NH-U12F cooled the CPU to 11ûC below the reference AMD HSF at low fan speed, and 12ûC below at high fan speed.

The NH-U12F is an effective HSF for Socket AM2 processors, although it's clearly only worth running the fan at low speed, as the extra noise generated by the fan at high speed barely improves its cooling ability. For LGA775 CPUs, the NH-U12F is barely any cooler than the reference Intel HSF, although it's considerably quieter. However, at close to £40, it's hard to recommend the NH-U12F when there are so many better HSFs from which to choose.

• Cases - 21st November 2008
• Motherboards - 24th October 2008
• Gaming Headsets - 26th September 2008
• Dream PCs - 24th September 2008
• Headphones - 12th September 2008
• Media PC components - 22nd August 2008
• PSUs - 14th July 2008

• OCZ Core Series 30GB - Hard disks / storage
• Western Digital Caviar Black 1TB - Hard disks / storage
• Asus EAH4870 TOP - Graphics cards
• Creative Sound Blaster X-Fi Titanium Fatal1ty Pro - Sound cards
• Multiwinia - Games
• Zotac GeForce GTX 260² - Graphics cards
• Sapphire Radeon HD 4850 X2 - Graphics cards