dual core vs. core 2 duo

[jes]

I have been told tat the dual core is just 32 bit and the core 2 duo is 64 bit. Is that right? Is that the only difference? What does the bit count even mean for a proccessor?

[saphalline]

Both of those CPU's are Core-based, thus they are both 64-bit capable using Intel's EM64T. However, the Pentium Dual-Core processor family is specifically deprecated in several ways that account for the much lower performance evaluations.

- It is limited to the "old" 800 MHz FSB
- It has only 1MB of unified L2 cache
- It is currently a dual-core-only design
- It lacks hardware virtualization (VT) support

While these limitations are significant enough to warrant the E2xxx performance codes, the Pentium Dual-Core is nevertheless a Core-based CPU and thus has decent performance despite all this. A HyperThreaded P4 of similar clock speed would have a tough time keeping up in most performance tests, and any Celeron would be creamed! Then again, a C2D E6550 can walk all over the PDC's, so you get what you pay for.

[preet]

The dual core processor E2160 is said to have a speed of 1.8 Ghz. Does this means that the 1.8ghz is per core resulting in 2*1.8 ghz? Or the overall speed is 1.8GHz!!!

[mjc]

It is the old series/parallel thing...the cores are running at the same speed and are NOT 'hooked up' in series, yes, the overall speed is 1.8 Ghz, but that doesn't really mean all that much any more. A 1.8 GHz 64 bit CPU is going to absolutely flatten a much higher speed 32 bit one any day, and not even break out in a sweat doing so...

[preet]

By the way how we could explain someone, a client for instance who is ignorant on the processor technology, that a Dual core processor or Core 2 Duo is much more effective than the Pentium D. As what the clients knows, is the higher the core speed the better the performance. For the instance the core 2 duo E4400 runs at 2 Ghz and the Pentium D at 3.4Ghz. Hence for him the Pentium D should be the fastest!!!

[saphalline]

You have to disassociate clock speed from performance. It's sort of like horsepower vs torque in an engine. The flip side to clock speed is IPC, or instructions per clock. This all gets rather complicated in a heartbeat when you get into issue widths and instruction retire rates, but suffice to say that clock speed is only meaningful when comparing other similar CPU's.

In the case of the Pentium Dual-Core and Core 2 Duo, the microarchitectures are the same while the core revisions are different (but not too much so). Comparisons related to clock speed are meaningful between these two CPU families, but not rock solid. At the same clock speed, the C2D will reign supreme. It has many advantages. At slightly slower speeds, the C2D will keep up with a PDC. In fact, the PDC would probably need a good 600-800 MHz clock speed advantage to beat any given C2D!

Taking it the other way, a P4 630 at 3 GHz with HyperThreading can't even hope to challenge a 1.8 GHz Pentium Dual-Core E2160 in most tests! While the P4's much higher clock speed would help it win a few low CPU-intensive tests (such as MP3 encoding) the PDC's true dual-core design and more efficient architecture would punish the P4 for being so "slow"! Take it up a notch with a Core 2 Duo E6550 at 2.33 GHz on a 1333 MHz FSB with twice the L2 cache of the P4 630, and it's game over! And if you want to make the P4 630 really cry in shame, put it next to an upcoming 3 GHz Penryn and watch it try to wriggle out of its socket! :p

CPU generations and new releases are about more than clock speed. They're about performance. If the lowly & cheap Pentium Dual-Core couldn't beat out a Celeron D, do you really think Intel would have released it? I haven't seen Intel release a dud since the PIII Coppermine 1.13 GHz back in 2000! All the IC/microprocessor manufacturers are more reliable these days, actually...

[saphalline]

By the way how we could explain someone, a client for instance who is ignorant on the processor technology [...]Show him/her/them benchmark charts! They're available all over the web! They really put things in perspective. It's one thing to know the technologies and the numbers, but it's a whole other story to see longer bar graphs! ;)

[PrntRhd]

Here is one such chart:
http://www23.tomshardware.com/cpu_2007.html

[saphalline]

I love that chart! :cool:

[jes]

That link did not work for me but I suspect that it is what I need to see as I am wondering about the comparison of the dual core and the core 2 duo.

There has been alot of information in this thread. I have found some of it quite interesting, though I admit , some of it has been a bit over my head. I have tried Google for a comparison chart but I must be using the wrong keywords.

[mjc]

What is shown in the post is the full link, so try copy and paste, instead of clicking it...

[PrntRhd]

link was down but up again.