Intel Core 2 Duo Platform

The Intel Core 2 Duo E6400 stepping B2 processor was overclocked from its default 2133MHz to 3500MHz (a 64.1% frequency growth) with a core voltage increase to 1.45V.

The CPU-Z program reports the core voltage wrong, but this won’t prevent us from analyzing the results of the tests.

The Enzotech Ultra-X confirms its superiority on the Intel Core 2 Duo platform, too. I should confess I had been rather skeptical about the thick pipes, but the tests changed my opinion. This product is an indisputable leader among air coolers in terms of performance, particularly quiet-mode performance! And if you don’t care about noise, the Enzotech Ultra-X is beyond competition, too. At its maximum speed of 2500rpm, this cooler allows squeezing an extra 100-200MHz from an overclocked processor.

I’d like to show you one more interesting thing. Remember I told you about how tight the Ultra-X’s base was pressed to the CPU heat-spreader on the LGA775 platform? Take a look at the graphs that show the temperature of the cores of the Intel Core 2 Duo processor when cooled by the Scythe Infinity with two 1200rpm fans (the core temperatures are shown in the cells below). But instead of looking at the max temperature of the hottest core (the red graph), take a look at the difference between the core temperatures (the red and yellow graphs):

And here’s the same for the Enzotech Ultra-X in the quiet mode:

To remind you, the Scythe Infinity is installed by simply pushing the locks through the holes in the mainboard, without a back-plate, just like the boxed cooler from Intel. But the Enzotech Ultra-X is fastened to the CPU with a back-plate and screws, very tight but without bending the mainboard. As a result, the difference between the temperatures of the cores is only 1 or 1.5°C. With the Scythe Infinity this difference amounts to 4-5°C!

Of course, this difference between the core temperatures, and the difference in performance of the coolers too, could not but affect the CPU’s overclocking potential as was proved by a small test. The Enzotech Ultra-X allowed to overclock the CPU by 110MHz more above the frequency the tests were performed at whereas the Scythe Infinity could lift the frequency bar by 30MHz only. I didn’t check the maximum CPU frequency with the other coolers, except for the Zalman CNPS9700 at 1750rpm for which 3.5GHz was the limit.