If you have been reading Frostytech for a while, you'll know that the reference Intel heatsink for the Core 2 Duo CPU family is based on Intel's Radial Curved Bifurcated Fin Heatsink (RCBFH) design. In all likelyhood this heatsink that Frostytech is testing today was manufactured by AVC - a large thermal solutions manufacturer which has made several Intel and AMD reference heatsinks.
The Intel RCBFH design is engineered to be cheap to produce, easy to install, and thermally efficient. This is the stock Core 2 Duo heatsink [Dim: 61x90x90mm, est. 380 grams ] , and it is generally speaking a well designed mass-produced cooler. The heatsink uses a suspended 4-pin PWM 84mm diameter Nidec F09A-12B1S2 fan [1500PM (est.), 12V, 0.20A], it conforms to ATX motherboard keep-out and high recommendations, and LGA775 weight restrictions.
As we'll show you, this stock Core 2 Duo heatsink relies on a unique central copper heatspreader pressed into a high aspect ratio extruded radially curved bifurcated aluminum fin.
The stock Intel Core 2 Duo heatsink is composed of two sections - the first an outer ring of extruded aluminum with 24mm long curved cooling fins, the second an internal 32mm diameter cylindrical copper heat spreader. The copper heat spreader makes direct contact with the processor integrated heat spreader, conducting the heat it absorbs out to a larger surface area in direct contact with the aluminum. The copper makes direct contact with the aluminum fin via a toleranced interference fit, so no thermal compound is used here.
Aluminum has a thermal conductivity of 247 W/mK, whereas copper (which is heavier and more costly) has a thermal conductivity of 398 W/mK. The technique of building heatsinks with copper centers and outer aluminum cooling fins has long been used to conduct heat energy quickly away from the CPU. The copper component quickly conducts that heat to a larger surface area which is in direct contact with the specially shaped aluminum cooling fins. From there, increased surface area and airflow disperse the heat into the surrounding environment.
With a 150W heat load applied by the Intel LGA775 version of FrostyTech's synthetic thermal test platform, the stock Intel Core 2 Duo heatsink yielded a rise above ambient temperature of 49.2°C (36.7dBA) at the fans' stock speed of 1500RPM. The CPU equivalents of this test would be an Intel Pentium D / Extreme Edition or Core 2 Quad class chip.
Next, the stock Intel Core 2 Duo heatsink was tested with an 85W heat load - akin to a Core 2 Duo processor. This test resulted in a satisfactory result of 29.0°C over ambient temperature, at default fan speed. These results form the basis from which other socket 775 Intel heatsinks can be compared. On the whole, the stock Intel Core 2 Duo heatsink performs satisfactorily on the 85W test, which is more in line with the actual thermal loads Core 2 Duo processors create.
Manufacturer ... Model No ... 150W Test ... 85W Test
( both tests : °C rise over ambient temp)
Thermalright ... Ultra 120 ... 17.8 ... 10.6
Zalman ... CNPS9700 LED ... 19.0 ... 10.4
Thermalright ... Ultra-90 ... 19.6 ... 13.0
Intel Stock ... Pentium D ... 40.3 ... 23.9
Intel Stock ... C2D ... 49.2 ... 29.0
pcstore said:Evercool Buffalo Heatpipe Cooler - check this one as well. quite good. I am using with Pentium D 940. keeps me cool.
I dont want to give link as that will void site rules![]()