Core 2 Duo overclocking

[Warwizard]

Hello!
Here are some questions. Please be patient, I need your help!

1.) From E6300, E6400 and E6600, which one can overclock better (i.e. reach a higher % from the original clock)?
2.) Which motherboards are recommended?
3.) Is a DDR2-800mhz 4-5-4-15 RAM as good as 4-4-4-12? If not, what can I expect from it?
4.) What will happen if I use DDR2-533mhz RAM?
5.) Which cooling fans are recommended?
6.) Apart from good motherboard, memory and cooling, do I need something else that worth mention?
7.) Will something slow down after I overclock? Do I have to underclock anything in order to overclock the CPU?
8.) Is it OK to overclock more than one thing at the same time, like CPU, RAM and graphics card?
9.) Does an overclocked Athlon 64 X2 4800+ (AM2) reach higher speeds than an overclocked E6300/E6400/E6600?

Any help will be appreciated.
Thanks. :)

[batboy]

1. The E6300 will give you the highest percentage O/C, assuming the motherboard you use can handle super high FSB.

2. For the E6300/E6400, you might want to check out the Asus P5B Deluxe or Gigabyte DS3. For the E6600, the Asus P5W DH is a good feature rich board. I'm waiting for the Abit AW9D which should be arriving in a couple more weeks.

3. It's hard to give a qualified answer about RAM from timing alone. But, most CAS 4 DDR2-800 will generally do DDR2-1000 speed with relaxed timings and a bump in voltage.

4. DDR2-533 will run fine at default speed, but if you start overclocking, at some point, you'll have to use a lower ratio (divider) which means you'll lose some potential performance.

5. Check out the cooling section for current fan choices.

6. In addition to CPU/mobo/RAM/cooling, you also need a good power supply.

7. Nothing should slow down if done right. You'll want to lock the PCI and PCI-E buses to their default 33 and 100 MHz speed, but as long as your RAM can run at least 1:1, then all will be good.

8. As long as the system is stable, meaning you haven't overclocked too far on CPU, memory, or vid card, then they can all be overclocked at once.

9. AMD currently has nothing that can come close to matching the performance of a Core 2 Duo.