please explain ram dividers

[neokeelo]

I think I understand this somewhat but not to the point I want to.

So If I am overclcoking an Intel 630 (3ghz) (15x multiplier)+with 2gb ddr2 ram 667

And I want to hit 4.0ghz I need to change my FSB to 267 (15x267 =4005mhz)

But what divider should I use on the ram? What does the divider make the ram run at at stock?

Since it runs at 667mhz that means its really running at 4x166.75 ???

Im confused.

Also if the ram is running faster than it's intended speed can I still try to lower the timings?
Which one should I try to lower first? Ram is rated at 4-4-4-8 @667mhz

 

[pigpen]

You wouldn't want to use a divider, your RAM is plenty fast to OC the chip to 4.0ghz. In short, DDR = Double Data Rate. So at stock (no divider) the RAM runs at twice the speed of the FSB. If you raise your FSB to 267, RAM will run at (267x2= 534mhz.) A divider is used when you want to OC the Chip without the OC also applying to the RAM. For example, with a 5:4 divider and an FSB of 267 your chip would run at 4005mhz (267x15), your RAM would run at 427mhz (267 x (5/4) x 2(DDR))

 

[pigpen]

Also if the ram is running faster than it's intended speed can I still try to lower the timings?
Which one should I try to lower first? Ram is rated at 4-4-4-8 @667mhz

You have it backwards. To clock the RAM higher than its intended speed, many times you would need to raise the timings. If your RAM is running slower than it's intended speeds, you can try and lower the timings.

 

[neokeelo]

ok i think i got it. So I would need to do this.

run a 5/4 divider than 267 x 1.25 (5/4) x 2 (ram multplies by 2, cpu by 4)
makes 667mhz ram
yOr I can try higher dividers if the ram overclocks good like a 4/3 might work good,
that would be 712mhz
With a little more voltage and slower timings.
So what is better, running 667Mhz with lower timings or 712Mhz with higher timings?
But I thought lower timings were crucial to gaming and mattered more than raw speed.