Features:
The 5610 cooler features aluminum heatsink fins which are stacked on two U shaped aluminum heatpipes. These 2 heatpipes help to dissipate the heat that is generated in the base that sits on the CPU. Ontop of the area where the heatpipes meet the base there is actually another small vertical heatsink (pictured below). This basically just serves as some intial cooling directly off the base, the hottest part of the cooler, before the heat is moved up the heatpipes and into the larger fins. The 80mm X 80mm X 25mm fan that is mounted onto the side of the heatsink fins efficiently removes the heat from the system. This is a nice design which keeps this cooler at a fairly small profile and weight. This cooler weighs in at 373 grams which is well below the 550 grams which Intel spec's as a safe weight for a CPU cooler.

 
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The PWM version has an adjustable speed fan which ranges in speed from 800 to 3200 rpm. At 3200 rpm the maximum air volume throughput is 51.3cfm. We found the fan noise at maximum speed to be certainly noticable, at about 34dB. When you are performing heavier demands on your system you can turn up the speed of the fan to 3200 rpm and eliminate the heat much more efficiently. For general processing you can turn the speed down which makes this cooler almost completely silent.

The Silent version has a constant fan speed of 1800 rpm with a fairly quiet 19dB rating. We found the noise level of this cooler to be very acceptable if you prefer not to have the adjustable version.

Installation:
In our case installation was a little bit more complicated because our system was already assembled and running. If this CPU cooler is installed during the building of your computer then the installation will be much less time consuming of course. In our case we had to unhook the 2 power supply cables, case panel connections, hard drive and CD ROM cables and our extra USB connections. We then removed the motherboard from the case and removed the current CPU cooler which just happened to be another heat pipe cooler of considerable larger size and weight. To install the IGLOO 5610 series cooler you first attach the mounting plate to the rear of your motherboard being sure to line up the threaded screw holes with the 4 mounting holes in your motherboard. This mounting plate is held onto the rear of your motherboard with 2 sided tape, and prevents you requiring a third hand later. With the mounting plate installed, you now place the cooler onto your CPU allowing the 4 mounting screws to pass through the motherboard into the mounting bracket. I recommend tightening the mounting screws a little bit at a time, in a criss-cross pattern, so as not to stress the CPU on one side only. After the IGLOO cooler is tightened down, just plug the fan wire into the motherboard and you are finished!

 
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Testing:
Testing system:
CPU: Intel Core 2 Quad Q6600 Quad-Core, 2.40 GHz, 1066 MHz FSB, 8MB L2 Cache, 65nm
Motherboard: ASUS P5B-PLUS
Memory: 2 GB dual channel of OCZ PC2 6400 (2 X 1 GB)
HDD: 2 X Seagate Barracuda (ST3250410AS) 7200 250GB SATA2, 1 X Seagate Barracuda (ST3320620AS) 7200 320GB SATA2, 1 X Seagate Barracuda (ST3500630AS) 7200 500GB SATA2
Video: ASUS EN8500GT Silent PCI-E
Power Supply: Silverstone SST-ST60F 600 Watts
OS: Microsoft Windows XP Professional SP2

Temperatures:

Conclusion:
This is a great performing Heat Pipe CPU cooling system in a compact design and light weight. With the adjustable fan on the PWM version or the low noise fan on the silent version, there is certainly an IGLOO cooler for every type of user. With it's very reasonable price this is certainly a CPU cooler worth considering when your building a new system, or just want to modify or upgrade your current cooling system.

Pros:
Quality aluminum design with copper base
Smaller size and weight than a lot of heatpipe coolers these days
Very sturdy mounting with the rear bracket, no fear of it coming loose
Adjustable fan on the PWM version
Fairly silent performance with the Silent version
Great performance

Cons:
Have to remove the motherboard to install on existing built systems