Determining system bus and fbs

i want to buy a new laptop but am confused about the relationship between bus speeds of motherboards, processors and ram. I want my new system to run at at least 800mhz. how can i know if there is a bottleneck at the motherboard or processor or ram? do processors and motherboards have restrictions on bus speeds or is it just the memory?

 

The motherboard supports a certain bus speed for processors and RAM. As an example, the Intel PM45 chipset supports up to 1067MHz for CPUs and either DDR2-800 OR DDR3-1067. This means you can run CPUs w/ FSB (front side bus) up to 1067MHz and RAM up to 800MHz (if the system uses DDR2) or 1067MHz for DDR3. An important note is that RAM can be faster but will downclock to the maximum speed (ie. DDR3-1333 will run at 1067MHz speeds), while CPUs with higher FSB would not work.

Do not worry as none of these numbers have an impact on real life performance. A CPU w/ 800MHz FSB will not performance noticeably worse than one with 1067MHz, assuming they share the same core frequency (ie. 2.0 GHz speed - if you are interested, this speed is calculated by the FSB divided by 4 (since CPUs are quad pumped, don't worry about this) times a multiplier, for this example 800MHz FSB / 4 x multiplier of 10).

I know this is probably more than you need to know, but factoring in RAM, if you are running DDR2-800, then the memory is running 1:1 with the FSB. If you are running DDR3-1067, there is a 4:3 divider so that the FSB is 800MHz (FSB and RAM are interrelated).

Either way, DON'T WORRY, none of these will bottleneck a computer. The limiting factor is usually the hard drive, then GPU, RAM amount (not speed), and finally the CPU speed (not FSB).

 

I think you need to worry more on how your processor relates with your motherboard since they can have compatibility issues..