question about double/quad pumped fsb's

[tokamak]

I just read Anand's article on the new p4. There is a section about how complicated it is for a motherboard to do double or quad pumped FSB. It got me to thinking, why don't they just make a 400 or 533mhz single pumped bus? Wouldnt that give the same effect? Then they could concentrate on simply increasing the speed instead of all the more complicated things they have to do to get it to send data 4 times per cycle.

 

[Athlon4all]

Well, it seems to me from my limited knowledge that EMI will become more and more of a problem if the actual frequency increases, also the packaging should become a problem as well as frequency (not just of the fsb but of the CPU core itself as well) (That may have been one of the reasons AMD's Athlon XP took so long to get out). Anyone care to corfirm so both my and tokamak can learn?

 

[Adul]

it becomes increasingly difficult to run bus at that speed and maintain reliable signal integrity.