Initial testing was performed on the two Intel-configured machines with Futuremark's PCMark05 benchmarking tools suite. This is a synthetic benchmarking package with basic scripted computational work loads of common functions performed by the average desktop user.
"The CPU test suite is a collection of tests that are run to isolate the performance of the CPU. The CPU Test Suite also includes multithreading: two of the test scenarios are run multithreaded; the other including two simultaneous tests and the other running four tests simultaneously. The remaining six tests are run single threaded. Operations include, File Compression/Decompression, Encryption/Decryption, Image Decompression, and Audio Compression" - Courtesy FutureMark Corp.
The quad-core Core 2 Extreme QX6700 is only showing about a 14% performance advantage over the dual core X6800 chip in the base CPU test module. We should note that an Athlon 64 FX-62 dual core processor scores around 5700 in the PCMark05 CPU test module.
The overall score actually shows the QX6700 slightly slower than the dual core Core 2 chip. Memory bandwidth with the quad-core system, is going to be undoubtedly slightly lower on a per-core basis, since four cores versus two are sharing front side bus bandwidth. Thus the lower overall weighted score. That and coupled with fact that the Core 2 Extreme X6800 has a slightly higher clock speed on each of it's dual cores and it becomes more clear how the numbers have scaled here in these synthetic benchmark runs.
3DMark06's built-in CPU test is a multi-threaded "gaming related" DirectX metric that's useful for comparing relative performance between similarly equipped systems. This test consists of two different 3D scenes that are generated with a software renderer, which is dependent on the host CPU's performance. This means that the calculations normally reserved for your 3D accelerator are instead sent to the central processor. The number of frames generated per second in each test are used to determine the final score. We've got the results from the CPU test and the overall score here...
Futuremark's 3DMark06 CPU test paints a dramatically different picture however. The quad-core Core 2 Extreme QX6700 boasts nearly 2X the performance number that is reported for the Core 2 Duo X6800 system, a dramatic increase to be sure. For another frame of reference, an Athlon 64 FX62 scores around 2090 in the 3DMark06 CPU test module.
The overall 3DMark06 score is weighted in with graphics subsystem performance as well. So the numbers are much tighter here since identical graphics cards were used in the test systems. Regardless, in 3DMark's DX9-based gaming environments, the QX6700 is around 8% faster even though it's held back more so by the graphics cards installed.