Results:

   Before I get to the mind blowing overclocked performance numbers, let's take a quick look at the stock performance of the E6400 wrapped with this particular hardware I listed at the top of this page. Then I'll list the overclocked performance under the stock results. Keep in mind that 2.13GHz is "stock" speed for this Intel E6400 Core 2 Duo.

3DMark05 @ 2.13GHz  7485 Marks	3DMark06 @ 2.13GHz 4099 Marks	PCMark05 @ 2.13Ghz 5901 Marks
3DMark05 @ 2.56GHz 7575 marks	3DMark06 @ 2.56GHz 4193 Marks	PCMark05 @ 2.56GHz 6634 Marks
3DMark05 @ 3.6GHz 7827 Marks	3DMark06 @ 3.6GHz 4352 Marks	PCMark05 @ 3.6GHz 8039 Marks!

   As you can see from the results above the 3DMark results do not change all that much even with the massive increase in CPU Mhz from 2.13GHz to 3.6GHz. That's because 3DMark05 and 06 both are heavily dependant on the graphics cards (hence '3D'Mark).

   However if you look over at PCMark05, the results have increased drastically from 2.13GHz to 3.6GHz. I was able to achieve over a 2000 mark increase! That's because obviously 'PC'Mark is more dependant of the rest of system hardware and of course, the CPU itself. 8039 PCMarks is definitely a record for any of my previous systems.

CPU Arithmetic  @ 2.13GHz	CPU Multimedia @ 2.13GHz	Memory Bandwidth @ 2.13GHz 800mhz
CPU Arithmetic @ 2.56GHz	CPU Multimedia @ 2.56GHz	Memory Bandwidth @ 2.56GHz 800mhz
CPU Arithmetic @ 2.8GHz	CPU Multimedia @ 2.8GHz	Memory Bandwidth @ 2.8GHz 800mhz
CPU Arithmetic @ 3.6GHz	CPU Multimedia @ 3.6GHz	Memory Bandwidth @ 3.6GHz 900mhz

   The Sisoft Sandra results are much more interesting, particularly the CPU Multimedia results. Even at the stock 2.13GHz speeds, this E6400 completely dominated the competition according to this program. Once overclocked, it appears to be in a future dimension somewhere as far as performance. All these results speak pretty much for themselves, so I'll elaborate on how I achieved some particular overclocks.

• 2.40GHz: 300mhz FSB, DDR2-800mhz, no CPU voltage increase.

• 2.56GHz: 320mhz FSB, DDR2-800mhz, no CPU voltage increase.

• 2.80GHz: 350mhz FSB, DDR2-800mhz, .1v CPU voltage increase.

• 3.20Ghz: 400mhz FSB, DDR2-800mhz, .15v CPU voltage increase.

• 3.60GHz: 450mhz FSB, DDR2-900mhz, .25v CPU voltage increase.

   You'll notice I listed some other speeds that I did not show test results for. To be honest, I used and tested so many different speeds that I had to narrow them down to show them all. I will say that probably 99% of everyone out there will be able to achieve 2.4GHz with no voltage increase. Most if not all should be able to get 2.56GHz without any voltage increase either. Getting 2.8GHz will probably take a touch more voltage, but just a pinch. Once you get over that, it gets very very warm. It'll certainly overclock higher, but if you plan on keeping it up there (ie. over 3Ghz), you'll want watercooling in my opinion.

   Typical software programs that monitor CPU temps, and shutdown if necessary, are defaulted to 60c. Let's just say it'll go off like a sound horn almost immediately if you're running cheap air cooling in the 3GHz area.

CPU-Z 3.6GHz @ 450 FSB

Click to Enlarge

900MHz 1:1 @ 3.6GHz

The Adventure Ends (for now):

   Overclocking the Core 2 Duo is extremely easy in my opinion, especially with a quality motherboard. It's actually dangerously easy because cranking this E6400 up past 3.2GHz was super easy, but the heat generated is the killer here. And if you don't monitor the temperatures you're crazy. I used the included AiSuite that came with this ASUS P5B Deluxe to monitor the temps from windows. Here you can see both the glory of an insane overclock, and also the incredible heat generated even though I'm using one of the best air coolers on the market; the Zalman CNPS9500. Here's some test bench pics after I installed the new air cooler.

Zalman Setup

Zalman Setup

   So because the heat is monstrous at 3.6GHz, even though it's completely stable, I will not be running 3.6GHz all the time right now until I install some watercooling. Once I do that I will surely take it further. However right now I seem to change it around from 2.56ghz to 3.2ghz normally. That keeps the heat in check and since I run my system 24/7, I don't want to burn it up.

   It's truly amazing to have a CPU that I can whip back and forth between 2.13GHz and 3.6GHz without a single issue hardware wise. And what's even cooler is I can take it from stock to incredible without even overclocking the memory! By simply adjusting the memory dividers I can keep this particular Supertalent memory at it's stock 1.8v, 800mhz and 4-4-3-8 timings! I love it. Or with a couple taps of the down arrow in the BIOS, I can switch it from 800mhz to a much higher MHz without messing up any other settings. It just doesn't get any better than this for the overclocker like me.

   Well I hope this article helps someone out there. Good luck out there and keep that chip cool! If you have any questions or comments, please head over the forums by clicking the VH forum link at the top of this article. Thanks for reading!