I am really a noob and have never overclocked a system ,so please dont mid these basic questions .I have many doubts can some one explain that what relation does the FSB and the clock multiplier has and during overclocking how does the clock change do we change the FSB speed or the multiplier , i am asking it for conroe and amd chips .The second problem is what is the cpu to ram ratio basically for ?.Thank You for your reply
The MOST IMPORTANT thing to remember about 64's is that all system timings’ are derived from the CPU clock, i.e. CPU, HTT Bus, Memory, even PCI/e.
And all those other system resources have some type of Multiplier/Divider associated with them that takes the original 200MHz CPU frequency (The Master clock if you will) and makes it;
2000MHz CPU (200MHz X 10 CPU Mult) or
2000MHz in the case of the HTT Bus (its really 200MHz X 5 HTT Mult =1000MHz, the HTT uses one clock cycle to both transmit and receive), or
400MHz in the case of Memory (its really 200MHz, but DDR uses both the leading and trailing edges of a single clock pulse to operate at twice the speed). In the case of memory a divider is used to generate the memory clock, ie.
1:1 = 200MHz(400MHz theoretically),
5:6 = 117MHz(333MHZ, that’s 200 X 0.83)...
The other buses are usually locked in Nf4 MB's, but don’t have to be, so make sure your bio's is set to LOCK the PCI Bus.
So when you raise the CPU master frequency, you also raise the HTT and Memory as well. So you need lower the Memory frequency as well as the HTT. To do that you need to be familiar with your Bios setting in-regards to Memory, which can be quite confusing.
I would recommend looking for a sticky in the forum that talk about memory timing and what they do.
My guess is you will have a setting that allows you to select AUTO or MANUAL memory timing and either allow setting a specific memory timing i.e. 400, 333, 266… or it will be a divider as indicated above. You need to set it to 333MHz or 5:6.
Your HTT will also have an AUTO/MANUAL selection with a X5, X4, X3... for the manual setting.
That will alow you to increase your CPU frequency w/o making the memory/HTT unstable.
Voltages also play into OCing, VCC is your CPU voltage and its default is probably 1.30V. You can probably get more from your OCing if you raise the VCC to 1.4V.