E6300, What does the fine print mean?

I am looking at buying an Intel E6300, the 45nm version.
I am still full of questions though. If it is a 2.7GHz processor, which is part of the Dual-core range, then do I double the 2.8?
Is it actually a 5.6GHz?
What does the 45nm mean as opposed to the 65nm?
Would I be better off getting a totally different processor (+\- $20)

I am confused, please help!

1. No it's not 5.6 ghz. It's just 2 cores running at 2.8 GHz. So if you ran a single core/thread application then only 1 core will be working.
2. 45 nm and 65 nm just means how thick the cpu is. The thinner the cpu is the better it can get rid of heat.
3. well you'll have to give the motherboard your looking at getting/ have to us. It just so that we can see whats cpus will work for you

No, having a dual core CPU does not double the clock speed, just the number of cores.
This means that your system can process more threads in parallel for a healthy bump in performance and responsiveness.
If the application can use more than one thread (multi threaded app), you will see much higher performance from it on a dual or quad core machine.

The 45nm and 65nm numbers refer to the size of the circuit traces used in the CPU core.
A smaller circut is generally better as it draws less power for the same speed and can usually be clocked higher.

Which CPU is best for you really depends on your budget and intended usage for this machine.
It would also be useful to know which components you already have.

No, you are not quite correct here.
The Athlon 3000+ really is a 1.8Ghz CPU.
At the time it was released, AMD was trying to market the fact their architecture was far more efficient than Intel's at the time.
They did this by marketing their CPUs relative performance to the original Pentium arch (please correct me if it was a different arch).
What they are trying to say is that their 1.8Ghz CPU gives you the performance of a 3Ghz Pentium CPU.

Intel, on the other hand, does not rate their CPUs as such instead giving it a simple product number.
The E6300 is simply their designation for a 2.8Ghz, 2Mb L2 Cache, Wolfdale based CPU.
The number has nothing to do with the performance of it as it merely places it in a product category.
Technically speaking, all their 45nm dual core CPUs are exactly the same differentiated only by the stock clock speeds and amount of enabled L2 Cache.

Just about any newer app benefits from a faster CPU (and the Wolfdale arch is FAR faster clock-for-clock than what you now have), not just games.
Your entire system and everything you do on it will be much more responsive.

Many newer apps (games included) are capable of utilising 2 or more threads.
Moving in to the future more and more apps will be designed to utilise an increasing number of threads.

Overclocking is the art of running your processor at a faster speed than stock (and a faster CPU = better performance).
It is fairly easy to do and generally safe (make sure to read the Core 2 Overclocking Sticky first).
Overclocking is a great way to add extra performance to a budget CPU.
You can usually far outperform an über expensive Extreme Edition CPU (which is running at stock) with even the cheapest CPU in its line.

Defiantly give it a try!
I would not be surprised if you could get your E6300 to 4Ghz, with a decent cooler.

Ok, I think I will try it.
I have met several people here in the forums who are very helpful; I'm sure they could help me out some.