XBitlabs does pretty good
cooler reviews. Here's their
review of the 212 Evo -- they're a bit unimpressed, but only because the Thermalright True Spirit was a better value. But the True Spirit is hard to find (NewEgg doesn't stock Thermalright last I checked) and the CoolerMaster coolers are often on sale at NewEgg, making the value calculation different. Also the Evo comes with mounts for a second fan, so you might get even better performance for just the cost of another fan (some aftermarket fans like the Noctua Focus Flow come with a PWM Y-cable so you can run two fans without losing software control. or you can buy a splitter separately )
lazy_boy wrote: also does any after market cooler takes more power/voltage than a stock cooler? Thanks
The only thing that uses power on the cooler is the fan, and they tend to run just a couple of watts -- power usage will vary more with the RPM of the fan than will from one kind to another. It's quite possible to run more than one fan off a single motherboard fan header; even some
monster coolers pull only 4W or so and run off a single header. So unless you're getting into water cooling with pumps and whatnot, it's really not something to worry about (and if it comes to that you can always power them directly from a molex off the PSU rather than a motherboard header: all you need is an adapter, which many HSFs include).
Edit: I just happened to be looking through a Z68 mobo manual yesterday (ASUS P8Z68-V/Gen3) and noticed it listed the max draw for the CPU fan as "1A (12W)" -- of course not all motherboards are the same but I expect that's pretty standard for modern notherboards, and leaves
plenty of headroom for multiple fans. (That motherboard actually has two PWM CPU fan headers, plus several other fan headers, so you could just about turn the case into a wind tunnel if you wanted to)