I thought athlons ran on a 200MHz fsb?

[Bohemian]

I see articles here about upping the speed on an athlon's fsb to 105MHz, etc but I thought all athlon's ran at a 200MHz fsb stock?
Maybe I'm just not so clever but that sounds like underclocking to me.
Maybe you're actually just upping the speed on a clock and the fsb runs off of a multiplier on that clock?
So when you say you got the fsb up to 105MHz you really mean the fsb is running at 210MHz and the clock (that the memory, multipliers for core freq., multipliers for the fsb, etc run off of) is running at 105MHz.
On most (maybe all) intel chips the fsb is the same as this clock speed so this has never been an issue but with amd we can no longer refer to this clock as fsb...we need a new name for it....maybe something like....."clock".

[Tom]

the FSB on Athlons is ddr so 105mhz is theoretically 210mhz like you guessed.

[Eriksson]

Tbirds/Durons runs on dual pumped 100mhz bus referred to as 200 mhz bus. If memory serves me correctly there is a similar thing is the new P4. Quad pumped 100mhz bus called 400mhz.

[dommer]

Does that mean that PC100 is actually running at 200 mhz? Or is it's clock frequency different?

[Big Mike]

PC100 Sdram does run at 100, what happens on an Athlon system is the CPU comunicates with the Northbridge at an effective 200 MHZ (as I remember its actually 100 mhz but it utilizes the rising and falling edge of the clock to make two transactions per cycle) but the Northbridge comunicates with the ram etc at their normal speeds, and it can run asynchronously (IE 133 MHZ to PC133 sdram) This is why the new DDR ram boards are spiffy because DDR ram utilizes the rising and falling clock as well and can communicate at the full bandwidth available to the northbridge/cpu link.