[nextpage title=”Introduction”]

During this IDF Fall 2006 we had the chance to benchmark the first Intel quad-core CPU for desktops, Core 2 Extreme QX6700 (codenamed Kentsfield) – which will be released only in November –, and compare its performance against a Core 2 Extreme X6800, today’s fastest CPU available. Let’s take a look!

We have already explained the technical details of the forthcoming Core 2 Extreme QX6700 on our Intel Quad-Core CPU Overview and Roadmap article. Basically, it will feature a 8 MB L2 memory cache (2x 4 MB), will run with a 1,066 MHz front side bus and will have its clock multiplier unlocked.

Below you will find some screenshots of the system with the Core 2 Extreme QX6700 installed.

Core 2 Extreme QX6700Figure 1: How Windows recognizes Core 2 Extreme QX6700.

Core 2 Extreme QX6700 Figure 2: Windows correctly recognizes Core 2 Extreme QX6700 as four CPUs.

Core 2 Extreme QX6700 Figure 3: Four CPUs available on task manager.

Core 2 Extreme QX6700 Figure 4: All Core 2 Extreme QX6700 specs on CPU-Z.

Core 2 Extreme QX6700 Figure 5: Details of Core 2 Extreme QX6700 caches.

[nextpage title=”How We Tested”]

The test bench consisted in two identical systems featuring the components listed below. The only variable component was the CPU being evaluated (Core 2 Extreme X6800 or Core 2 Extreme QX6700).

Core 2 Extreme QX6700 Figure 6: Our test bench.

Hardware Configuration

  • Motherboard: Intel D975XBX2 Rev. 303 (BX97520J.86A.1446.2006.0913.1039 BIOS).
  • Memory: Two Corsair PC8500 CM2X1024-8500 modules with 1 GB each, installed under DDR2 dual channel configuration (5-5-5-15 timings).
  • Hard Drive: Seagate Barracuda 7200.10 (320 GB, 7,200 rpm, SATA-300)
  • Video Card: eVGA GeForce 7950 GX2.

Software Configuration

  • Windows XP Professional installed using NTFS
  • Service Pack 2
  • DirectX 9.0c

Driver Versions

  • NVIDIA video driver version : 91.47
  • Intel Inf driver version:
  • All motherboard drivers

Used Software

We adopted a 3% error margin; thus, differences below 3% cannot be considered relevant. In other words, products with a performance difference below 3% should be considered as having similar performance.

[nextpage title=”Results”]

You can see the performance results in the table below. Keep in mind that Core 2 Extreme X6800 runs at a higher clock rate (2.93 GHz) than Core 2 QX6700 (2,66 GHz). For DivX, Sony Vegas and 3ds Max the results are given in seconds, so the lower the better.

Program Core 2 Extreme X6800 Core 2 Extreme QX6700 Difference
Divx 6.2.5 with XMPEG 5.03 (seconds) 106 77 27.35%
Sony Vegas 7.0a Build 115 (seconds) 382 253 33.77%
3ds Max 8 SP2 (seconds) 80 49 38.75%
POV-Ray Beta 15 1428 2594 81.65%
PCMark05 Professional 1.1.0 (Overall) 7689 7575 -1.48%
PCMark05 Professional 1.1.0 (CPU) 7425 8492 14.37%
3DMark06 Professional 1.0.2 (Overall) 8281 8910 7.60%
3DMark06 Professional 1.0.2 (CPU) 2508 3981 58.73%

On the chart below you can see the performance difference between the two CPUs in percent. The chart indicates by how much Core 2 Extreme QX6700 is faster than Core 2 Extreme X6800.

Core 2 Extreme QX6700

As you can see the CPUs achieved similar performance on PCMark05 overall test suit. On 3DMark06 the performance difference between the two CPUs wasn’t big (7.60%), which does not surprise us at all, since 3D performance nowadays depends a lot on the video card being used. Also, keep in mind that the two CPUs run at different clock rates, Core 2 Extreme QX6700 running at 2.66 GHz while Core 2 Extreme X6800 runs at 2.93 GHz.

The performance difference on the 3DMark06 CPU test was impressive (60%), however this specific CPU performance increase does not necessarily translates into a higher 3D performance – as we mentioned, 3D performance measured by this program increased only 7.60%.

The real difference between the two CPUs is seen on programs that take advantage of symmetric multiprocessing, especially rendering. On 3ds Max the performance difference was over 60% and on POV-Ray we could see a stunning 80% performance increase. Video editing will also benefit a lot of quad-core CPUs, as Core 2 Extreme QX6700 was 50% faster than Core 2 Extreme X6800 here. Even MPEG decoding will be benefited by quad-core technology, as you can see.

[nextpage title=”Conclusions”]

We were impressed by the results. Quad-core technology will definitely improve performance for 3D rendering, video editing and video compression/decompression. Which was really interesting to note was that the new Core 2 Extreme QX6700 CPU runs at a lower clock rate (2.66 GHz against 2.93 GHz on Core 2 Extreme X6800) and yet was between 38% and 82% faster for those tasks. So if we had two CPUs running at the same clock rate, the performance difference would be a lot higher.

The best way to really evaluate the forthcoming Core 2 Duo Extreme QX6700 would be comparing it to a Core 2 Duo E6700, which also runs at 2.66 GHz. Unfortunately we were restricted to the two systems provided by Intel.

However, we still have to check how the increase in the number of CPU cores will affect mainstream programs, like Microsoft Office, anti-virus and e-mail, and also games. Unfortunately Intel gave us only a limited amount of time to test the systems and we could only run programs that were already installed on the systems. We couldn’t run a benchmark like SYSmark, which simulates the use of mainstream programs, and we also couldn’t run any games on the new quad-core CPU.

This is just a preview of the performance you should expect from the new Core 2 Extreme QX6700. Hopefully Intel will send us a sample at its launch timeframe, when we will be able to do a more detailed review and also compare it to Core 2 Duo E6700 for a real quad-core vs. duo-core match.