a question about syncronisation between cpu ram and mb

[ilyas001]

hi guys i know that the sdram have s that stands for synchronized which means that now the ram and the cpu workd at the same clock speed but what i don't get is that for exemple a cpu of 3.4 ghz speed run very very well with a 800 mhz of speed . why ?  how can we syncronise between 800 mhz and 3.4 ghz  and it goes the same with all kinds of rams and cpu and motherboards thanks 

[zMeul]

what CPU is it?

and 800Mhz sounds like DDR2?

[ilyas001]

2 minutes ago, zMeul said:

what CPU is it?

and 800Mhz sounds like DDR2?

i don't have this configuration i was just giving an example it does not really matter ok so let's say i have an i7 2600k at 3.4 ghz and a 1333 mhz ram frequency it does not change my question still how can you sync 1.3 ghz with 4 cour 3.4 ghz 

[zMeul]

5 hours ago, ilyas001 said:

i don't have this configuration i was just giving an example it does not really matter ok so let's say i have an i7 2600k at 3.4 ghz and a 1333 mhz ram frequency it does not change my question still how can you sync 1.3 ghz with 4 cour 3.4 ghz 

CPUs run at a base freq that is multiplied, the base freq is 100Mhz

 

and uses a similar multiplier to sync with RAM

 

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if I'm wrong, someone correct me

[ilyas001]

can you tell me more about this ?  i don't see the picture yet 

[SLAYR]

2 hours ago, ilyas001 said:

can you tell me more about this ?  i don't see the picture yet 

This is a diagram is a bit old, but the north bridge is connected to the cpu by something called the front side bus, which is the base frequency from which the cpu frequency, and memory frequencies are derived from by multiplying the fsb value by some multipler that is unique to the the component ( the cpu will have its multiplier and the ram will also have its own multiplier)

 

But for todays cpus (execpt for the amd fx series) the northbridge has been removed from the motherboard and integrated onto the cpu die, and the northbridge is now just part of the cpu, so there is no need for the fsb, but since there is stil a bus which connects the cpu and what remains of the northbridge that pretty much acts lime the fsb, and is called the baseclock (BCLK) frequency.