The importance of RAM Divider?

[Darthe]

Have just finnished re-seating my processor for better thermal contact and tiding up the inside of my case for better airflow, and am ready to attempt my first overclock this weekend.

But I've been getting rather confused with the relationship of CPU FSB to RAM speed. I've got this mental picture of matching the two (1:1) providing the most efficient combination, but is it more important in terms of performance then trying to overclock the hell out of my processor and ram frequency?

I'm using an E6600 with 2GB of the ever popular Geil Ultra 6400 (800MHz), and the setup I see the most posted here seems to be reducing the multiplier to 8 and increasing the FSB to 400 ( resulting in a 3.2GHz overclock with a 1:1 divider ratio). I'm not sure if I'll be able to reach those values with mu current cooler however (a Zalman CNPS7000), with current temps of mid-30s for idle and high 40s for load. What should I settle for?

While I'm at it, whats the gain in increasing RAM frequency compared to memory timings? I've discovered that my Giel Ultra advertised on this site (¬¬) as 4-4-4-12 at 400Mhz (800Mhz) actually does 5-5-5-15, and only hits 4-4-4-12 at a lower frequency of 333MHz (666Mhz?). Which is the more important; frequency or timings, or how do I find the best balance between the two?

Would it be worthwhile aiming for a CPU FSB of 333 (x9 multiplier) and dropping the RAM fequency down to match it?

Cheers for clearing up my confusion,

DS.

 

[Marse]

A ratio of 1:1 is convenient as you build up your overclock because it limits the speed at which your ram will run - to the FSB you have set at each stage. Hence it's appeal.

A different ratio could easily mean overclocking the ram which may be undesirable and unnecessary to achieve a given CPU speed.

If your maximum overclock just happens to be 3.2 GHz this is very convenient with PC6400 ram because with an 8 x CPU Multiplier you will achieve 3.2 GHz and 1:1 will mean the ram is running at it's rated speed.

I believe most argue that raw CPU speed is King.
Whilst it's desirable to run your Ram at it's rated speed, or as close to it as you can manage, most would argue that you should not significantly compromise CPU Speed in the process.

In some circumstances the compromise could be substantial.

Edit:

I overclocked to 3.6 GHz which meant my ram was running at it's rated speed.
I then decided the extra 200 MHz wouldn't have much practical impact and I dropped back to 3.4 GHz.

This gave lower temps and allowed me to re-install the original very quiet fans, obviously with reduced airflow, and I now have a quieter PC with reasonable temps.
This means that my ram is now running at 378 instead of the preferred 400.

When you overclock you will have to decide, taking increased temps into account, whether going as high as possible is worth it or whether something rather lower could be a better option.

It may be a question of balancing CPU Speed, temps, noise and even Ram Speed.