I've had this thing sittin' on my 2.1GHz E6420 for over two years now and it's still runnin' at 3GHz with no complaints. Best value for performance for a HSF I've ever seen.

I second the praise that Shinare stated. I have an older Q9550 overclocked and stable using this cooler.

A few items to note. If you've ever installed a heatsink on a socket 775 CPU, you know what I mean. Also, the fan doesn't spin up immediately when you start the PC, which could set off a sensor.

Lastly, since I have an older CPU, I'm not sure how well this product will work on the newer sockets for the i3/i5 and i7. Hopefully, there are others reading this post that can give their opinion to assist everyone.

Whether the fan spins up when you start the PC is determined by the specific motherboard, and/or its bios. It doesn't have anything to do with this heatsink/fan in particular.

It's a fair heatsink for the price, but if you're patient you'll find several that are equivalent for around this price. The supposed noise reducing rubber fan mounts don't really do much, decent fans are well enough balanced they aren't needed so basically it just means you'll have a harder time replacing the fan someday, though it's not hard to strap a standard full frame fan on with a few nylon wire ties if that day comes.