Amazingly enough, the Thermalright Ultra-90 heatsink is almost as powerful as the larger Ultra-120 heatsink. As you might have guessed the numbers trailing the 'Ultra' relate to fan size; 92mm or 120mm. Like the Ultra-120, the Thermalright Ultra-90 heatsink is built around three U-shaped heat pipes, a few dozen widely spaced aluminum cooling fins and a copper base plate. The heatsink is sold without a fan, the idea being it allows users to customize it with the fan of their choice. A good low speed 92mm fan translates into quiet cooling, or a high speed 92mm fan would yield lower temperatures with some sacrifices to sound output. The Thermalright Ultra-90 heatsink is more compact than its brethern, but remarkably the performance differences aren't nearly as large as you might expect. The only downside for us was the lack of fan clips.... once again a paper clip saves the day.

The Thermalright Ultra-90 heatsink is compatible with socket 775 Intel Pentium and Core 2 Duo CPUs, and after a quick mounting bracket change with socket 754/939/940/AM2 AMD Athlon64 processors. This model is generally sold in Intel or AMD configurations, the only difference being which mounting bracket is included. The 940-pin socket AM2 heatsink retention frame can be purchased separately if desired, for this review Frostytech will be testing the Thermalright Ultra-90 on both Intel and AMD platforms.

Resembling a block of downtown apartments, the Ultra-90 stands 147mm high in shimmering nickel-plated glory. The array of aluminum fins, copper heatpipes, and the small copper base plate have all received a nickel plating. This allows all joints to be soldered for low thermal resistance. The Ultra-90 heatsink weighs 435grams without a fan installed, and retails for in the region of $45CDN ($40USD). Over the next three pages of this Frostytech review, we'll tell you if the Thermalright Ultra-90 is worth that $40 bucks or not...

Thermalright Ultra-90 Heatsink

heatsink specsheet manufacturer: thermalright model no.: ultra-90 materials: nickel plated aluminum fins and copper base, three heatpipes. fan mfg: zalman ps92252h (as tested, fan not included) fan spec: 2800rpm, 12v, 3.36w (as tested, fan not included) fan dim: 25x92x92mm heatsink dim: 147x50x102mm weight: 435 grams includes: lga775 and k8 socket mounting hardware, am2 hsrm, thermal compound, printed instructions Compatible with Sockets: LGA775, 754/939/940, AM2. Est. Pricing: $40USD ($45CDN)

Thermalright have designed the Ultra-90 with widely spaced aluminum that have a slight curve to them. This apparently allows lower velocity air to pass through the heatsink with less resistance. To induce turbulence within the fins and improve thermal transmission between the air and metal, the aluminum fins have been modified by adding "proprietary bent winglets." In other words, the leading and trailing edges along either side of the aluminum fins are bent 15° up and 15° down respectively.

The three 6mm heat pipes, which join all the components of the heatsink together, are soldered in place to reduced thermal resistance at the joints. The heatsink is held and place on the motherboard with bolt-through-board retention brackets and spring tensioned screws.

The mounting hardware is uncomplicated, and very easy to set up and install even within a fully installed computer.

Plenty-O-brackets

The Thermalright Ultra-90 heatsink ships with brackets for LGA775 and AMD K8 processors (754/939/940/AM2 respectively).

The Intel socket 775 clip uses the standard push-to-lock plastic clips that insert into the four motherboard holes around the processor socket. AMD Athlon64 processors on 754/939/940/AM2 work with a modified spring clip that attaches to the lugs on the AMD heatsink retention frame. A cam lever at the center of the clip applies pressure to the heatsink base directly.

After the clips are in place for whichever CPU you are installing the Ultra-90 on, the next step is to install your own 90mm fan. Thermalright provide special wire clips to hold the fan in place, although none were included in the unit FrostyTech received for testing (bent paper clips work fine).

The Thermalright Ultra-90 heatsink will be tested on FrostyTech's Intel LGA775 and K8 version of the Mk.II synthetic thermal temperature test platform, and compared against several reference LGA775 and K8 heatsinks. The whole test methodology is outlined in detail here if you'd like 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 thermal performance!