Sorry to intervene, but i believe that it depends on the application. A higher Bclk would be better if the application was bandwidth hungry, but since most CPUs today are fed quite well by the bus a higher clock speed would usually be faster for most applications and games.
^ Agree here. Increasing the bus speed and lowering the multiplier is an old left over trick from days gone by when bus speeds were a lot slower than they are today. With the quad pumped bus's today, the bus is not the bottleneck it used to be.
It means Base Clock, and the higher you go, the more voltage comes to play in maintaining stability... For instance, when overclocking my I7920, after 4.2 ghz, i need to start up my voltage a tad bit... A higher bus speed is always faster that a higher multiplier for the same overclock, like everyone has already mentioned... Good job guys...
Actually bclk is just a reference. You can up your memory, qpi, uncore and cpu by upping the multipliers without upping the bclk and end up with the same results.
The problem is that unless you have an extreme edition cpu you can't raise the cpu multi so to get the cpu speed you have to raise the bclk on the non EE cpu's.
You just can't make a blanket statement that at a given cpu speed a higher bclk will perform better than a lower one. I depends on how fast everything else is running.
Bclk is not the same as fsb and the same rules don't apply.