A funny thing happened to CPUs recently, some of them got a lot more power efficient and a lot cooler. A few AMD Athlon and Phenom processors are pushing out as little as 80W, others as little as 65W or even 45W! Die shrinks are making mainstream and entry level processors much more energy efficient, and substantially more affordable too. If you've recently built a PC system with one of these energy efficient CPUs, you might be able to get away with a plain and compact heatsink that doesn't cost a whole lot.

You can save a lot of money on the CPU heatsink if you know that a processor with a TDP (Thermal Design Power) of under 90W doesn't require a $80 heatsink. In fact, if the CPU heat output is low, a dead simple extruded aluminum heatsink will probably be sufficient. Take for example the heatsink Frostytech is testing today; the Glacialtech Igloo 7321 Silent E.

The Igloo 7321 Silent E is a moderately compact AMD K8 heatsink, made just of extruded aluminum and an 80mm fan. The Glacialtech Igloo 7321 Silent E is rated for a maximum load of 89W, and is very quiet. The heatsink stands 71mm tall and comes with a fixed speed 80mm fan that rotates at a quiet 2000RPM. Weighing in at a light 380 grams, the Igloo 7321 Silent E is compatible with AMD socket 754/939/940/AM2 processors of 89W TDP or less. Frostytech tested the heatsink up to 125W, and the results weren't satisfactory.

Glacialtech Igloo 7321 Silent Light E Heatsink
	heatsink specsheet manufacturer: glacialtech model no.: igloo 7321 silent e materials: extruded aluminum fan mfg: powerlogic pla08025s12l fan spec: 2000rpm, 12v, 0.10a fan dim: 25x80x80mm heatsink & fan dim: 71x84x85mm weight: 380 grams includes: thermal compound, instructions Compatible with Sockets: 754/939/940/AM2 Est. Pricing: $20USD ($20CDN)

There's not a lot else that needs to be said about the Glacialtech Igloo 7321 Silent E heatsink, other than to reiterate that it's best suited to smaller enclosures where vertical height is restricted, and to energy efficient processors that don't run very hot.

Base Finish and Flatness

Flipping a heatsink over to inspect the business end is often a simple indicator of overall cooler quality. More practically speaking, a heatsink is in many ways only as effective as the contact it makes with the processor - the flatter and smoother the better. Base finish is one of the criteria that Frostytech measure in the course of evaluating heatsinks, and it involves two distinct aspects. Surface Finish is the first; this is calculated with the aid of Surface Roughness Comparator that has a cross section of common machine surface finishes and their numerical surface roughness equivalents in microinches. The second is Surface Flatness. This is tested with an engineers straight edge or proven flat surface, in two axis.

The base of the Glacialtech Igloo 7321 Silent E heatsink has a surface roughness of ~32 microinches. The base is 77x40mm in size and generally quite flat in both axis. A patch of good quality shin-etsu thermal compound is pre-applied for easy installation.

FrostyTech's Test Methodologies are outlined in detail here if you care to know what equipment is used, and the parameters under which the tests are conducted. Now let's move forward and take a closer look at this heatsink, its acoustic characteristics, and of course its performance in the thermal tests!