Dual Core Or Quad Core?

[Disastrous]

Hey guys. I'm looking at upgrading my PC and I've come across an
interesting problem:

- Pay £165 for a Intel Dual Core E6850 (clocked @ 3.0GHz)

- Pay £160 for a Quad Core Q6600 (clocked @ 2.4GHz)

Now to my untrained eye, the quad-core seems like an easy choice. Am I
correct, or is the performance benefit from the 2 additional cores
completely lost by the low bandwidth connection between the 2 dies, as
mentioned in a Wikipedia article below:

"A quad-core CPU (as a two-die set in particular), however, can rarely
double the processing ability of each of its constituent halves (e.g.
the Kentsfield rarely doubles the ability of the Conroe), due to a
loss
of performance resulting from connecting them (i.e. sharing the narrow
memory bandwidth, and operating system overhead of handling twice as
many cores and threads)."

Will all applications for Windows eventually become multi-threaded and
fully utilise a quad core setup? Because if so then surely the 2.4GHz
quad core would outperform the 3.0GHz dual core in the future?

Basically this comes down to dual core vs. quad core, and I'm hoping
there's a clear consensus about which to buy!

Kind Regards

[Expertz]

I had the same decision to make, and I went with the Q6600. At the very
least Crysis detects and uses the 4 cores. SetiBOINC also runs very nicely
using 4 cores.

[T.J.]

As Expertz pointed out, if you join any of the distributed computing projects,
the quad wins, because they have SMP clients that will fully use all 4 cores.
Folding@Home (http://folding.stanford.edu) is my favorite DC project, but there
are a couple other worthy ones out there.

For single-threaded apps, though, the higher clock speed of the 6850 wins. Once
you offload background apps like antivirus, firewall, etc to another core, your
foreground app can take full advantage of the clock speed of the remaining core.

If you're a gamer, more of them are coming out that are multi-threaded, but I
don't know how many of them will take advantage of more than 2 cores.

I went for the 6850. If I decide a quad will work better in the future, when
the clock speed is up and the price down, I can upgrade with a simple CPU swap.