[James Justin Harrell]

Processors list a FSB speed, and motherboards list a FSB speed. RAM also has a speed, although for some reason the units (MHz) are usually left off.

But I'm wondering, do all these speeds have to match? Or, if a slower item is paired with faster items, will they all just use the slowest speed?

Example: If you want to use a processor that has a 1066MHz FSB, do you have to use DDR2 1066 memory and a motherboard with a 1066MHz FSB?

[dice14u]

Ok well for processors they have a front side bus and a multiplier to get their clock speed. The bus speed that is listed is the most stable for that processor, motherboards usually can dynamically set their front side bus or it can be set with the bios. If you set your FSB too high the CPU will not be able to handle it. Now as for the memory same concept stability vs productivity. Though I would say stick with the defaults Overclocking is tricky business. The values you see are about stability.
Also I wouldn't suggest using something like a 1066 FSB motherboard with a 800 mhz memory as it will just bottleneck the system to that speed.

[Thunderer]

So, I would would want to buy the newest CPU (i.e. Intel QX9770) which has an FSB of 1600, then the 780i mobo is DDR2 so I cannot buy 1600Mhz RAM. What would you suggest?

[alex]

Originally Posted by dice14u Also I wouldn't suggest using something like a 1066 FSB motherboard with a 800 mhz memory as it will just bottleneck the system to that speed.

Why not?

FSB's are quad-pumped, so a 1066 is true 266mhz.

ram is double-pumped, meaning true 400mhz.

Where's the bottleneck? Even taking into account the bandwidth requirements of a dual-core.

If you were running ram that, at true speed, was slower than the true speed of the fsb then you'd have problems, not just bottlenecks.