Why Core 2 Duo outperforms Pentium Dual Core even when C2D has lower clock Speed??

Hello friends,
I m very eager to know that whats the actual difference between a Core 2 Duo processor and a Pentium Dual Core processor, other than their proceesing architecture?

According to most benchmarking sites including Tom's Hardware, Core 2 Duo E4300 or 6300 performs better than Pentium Dual Core 820 in almost all benchmarks.....whereas C2D E4300 or E6300(1.8 and 1.86 Ghz respectievely) are having MUCH lower clock speeds than Pentium D 820(2.8Ghz). Why like this???

I have 2 systems, one with C2D E4300 1.86 Ghz and another(from which I am writing this thread) is Pentium D 820 2.8Ghz. But I dont see any MUCH performance difference in reality, although in multi-tasking and gaming C2D system still performs better.

Can anybody please explain me in details.....
Thanks in advance.
Regards,
TheHacker

The Core 2 Duo doesn't share the same architecture as the older NetBurst architecture of the Pentium D, which is also shared by the Pentium 4. The Pentium D is effectively a pair of Pentium 4 CPUs on one die. The Core 2 Duo architecture allows for a lot more processing to be done in one cycle, hence more information can be pushed in, say, 1 million cycles by the Core 2 Duo than the Pentium D. As for 'reality', there obviously won't be much difference when both systems are used for stuff like playing music etc. But the real differences will show up when you tax them, such as when playing an HD video without a video card supporting HD-decoding where the Core 2 Duo will be able to process information much more quicker than the Pentium D and so you will have a smoother image. Check on Wikipedia for more in-depth details.

Any type of encoding (audio/video) will be significantly faster on the Core 2 Duo as well. I also believe power consumption figures are in favor of the Core 2 Duo when compared to the Pentium D.

Pentium Dual Core uses the same architecture of the Core 2 Duo. You are referring to Pentium D, which is very, very different. Pentium Dual Cores are just basically stripped down Core 2s, while Pentium D is based on the old infamously inefficient Pentium 4s.

Basically a Pentium D is a dual core Pentium 4. While Core 2 Duo's use new technology making them uber fast.

@Metal X

I never knew that Pentium D and Pentium Dual Core are different things.
Is it really?
Can you/anyone please provide me a link from where I can get a clear idea about this??

I'm not sure there's an official page on the Intel website about it but quite a few tech sites have talked about it. Intel retired the Pentium name a while after introducing the Core CPU (Core Solo, Core Duo, Core 2 Duo, etc.) but for some reason decided to bring it back but only as a mobile part. So for mobiles you now have the Intel Celeron, the Intel Pentium (both being more or less equal) & the Core 2 Duo.

Confusing yet ?

Look here for information on the Pentium Dual-Core processors.
@Didou, there's a Pentium Dual-Core mobile part too? I thought the last Pentium part before the Dual-Core was the Pentium M? Are the Penryn CPUs going to be rebranded as Pentium ones? :S

Intel (for some reason) decided to bring back the Pentium name. I too didn't see the logic in the move since it only adds confusion for consumers.

Who knows what happens when you let marketing into the decision making process? Naming protocols defy all logic!

i guess Core 2 duo has more L2 cache(4mb)

No, same L2 Cache as Pentium D.

The new generation is ocming through with 8mb and more so it does make a big difference.