Intel Core 2 Duo & Core 2 Extreme Processors, Chipsets And Performance Analysis

For the past few weeks, we've been testing a pair of new processors from Intel, the Core 2 Duo E6700 and the new flagship Core 2 Extreme X6800.  Before we got down and dirty with the benchmarks, we spent some quality time with these two processors to get a feel for their performance in day-to-day use, and also spent some time overclocking.  For now, let's get some particulars out of the way...

CPU-Z Details Core 2 Duo E6700 2.66GHz

CPU-Z Details Core 2 Duo E6700 2.66GHz

CPU-Z Details Core 2 Extreme X6800 2.93GHz

CPU-Z Details Core 2 Extreme X6800 2.93GHz

First up, we have some information courtesy of CPU-Z.  We fired up CPU-Z to get a closer look at the internal workings of the Core 2 Duo E6700 and Core 2 Extreme X6800 processors.  Please note, that the 1600MHz clock speed reported by CPU-Z for both processors was a result of Intel's SpeedStep technology cranking down the CPU frequency while idling to conserve power. Also note that a full 4MB of cache is reported for both CPU cores.  These processors do not sport 8MB of total L2 cache, but because Intel's Advanced Smart Cache technology can dynamically allocate some or all of the cache to each core, CPU-Z is "tricked" into reporting double the amount of actual L2 cache per core.

The first pair of screenshots on the left contain details regarding the Core 2 Duo E6700 processor.  Although a lower speed is reported here due to SpeedStep, the Core 2 Duo E6700 actually runs at a default frequency of 2.66GHz (10 x 266MHz) with a 1066MHz FSB (266MHz Quad-Pumped).  The Core 2 Extreme E6800 is similar, but it has a default multiplier of 11, for a final clock speed of 2.93GHz.  The Core 2 Extreme E6800 is also "unlocked", so enthusiasts can alter the multiplier manually with some advanced motherboards for more flexible overclocking. Voltages vary depending on load, but in their idle state, CPU-Z reported a scant 1.2v supplying each CPU.

Both processors are manufactured on Intel's 65nm process node, and unlike the CPU's we tested last month in a closed door session in NYC, both of the processors seen here are based on the same stepping and revision, F and B1, respectively.

Core 2 Extreme X6800 Overclocked to 3.55GHz

Core 2 Extreme X6800 Overclocked to 3.55GHz

Overclocking: Due to the fact that the new Core 2 micro-architecture features a shorter pipeline than current Netburst-based Pentium D processors (14 stages vs. 31 stages), some analysts were concerned that Intel wouldn't be able to hit sufficiently high clock speeds at launch to push the Core 2 family of processor's performance much higher than currently available processors. Looking back at our Conroe performance "sneak peak" articles, you already know that didn't turn out to be the case and the Core 2 Duo is performing just fine, even though the highest clocked Core 2 processor has a frequency almost 900MHz lower than Intel's fastest Pentium D.

Of course, with a shorter pipeline, the higher clock speeds of current Pentium D processors will not be possible with a Core 2 until more advanced manufacturing processes are used. But there is always some headroom left under the hood, so we overclocked the E6700 and X6800 to see just how fast these early samples would go. In the end, we had trouble hitting a stable 3.3GHz with the E6700.  We're unsure if the motherboard or the CPU was hitting a wall, however, and will have to experiment further. Our Core 2 Extreme E6800 though, turned out to be a demon of an overclocker.  With a simple bump in voltage up to 1.425v, and FSB manipulation, we were able to hit a completely stable 3.55GHz using a Thermaltake Mini-Typhoon air cooler.  We've got some screenshots with Cinebench and SANDRA performance data above to give you an idea as to just how fast the Core 2 Extreme E6800 was at this high clock speed.

We also have some information regarding temperatures with both processors running at their stock and overclocked speeds.  The Core 2 Extreme E6800 typically idled at about 42^oC and peaked at about 56^oC under load when at its default 2.93GHz.  While overclocked though, the X6800 idled at about 53^oC and peaked at a toasty 66^oC.  The E6700 ran somewhat cooler with stock idle and load temps of 41^oC and 49^oC, and overclocked temperatures of 45^oC and 56^oC.  Of course, these are "only" the temperatures as they're interpreted by Intel's D975XBX motherboard. A different motherboard would likely report different temperatures.