Multicore CPUs

[d000hg]

1)The P4 reached something in excess of 3GHz (3.4GHz?) in single-core configuration, but a year later it seems dual/quad-core chips are yet to reach 3GHz.
Does this mean that a single-threaded application will actually run slower, or does the lower clock-speed hide the fact that individual instructions will take less cycles?

2)What difference is there in terms of performance & cost between getting a dual-CPU motherboard and two dual-core CPUs, or a single quad-core CPU?

[rik]

Here are several links from both Intel and Toms Hardware that hopefully will be what you are looking for. I haven't read them all yet but they seem to hold the answers you seek Grasshopper.

http://www.intel.com/multi-core/docs.htm

http://www23.tomshardware.com/cpu.html

[Grim]

Not a chance.
What you have to bear in mind is that really, it doesnt come down to MHZ freq SOLEY, when you're thinking about the overall performance of a chip..

There are other factors to consider, such as the FSB, Caches (L1, L2, and L3 where the case may be, Cache Sizes!, Cache Speed, and the core.
All in all, everything adds up.