How does double and quad pumping a cpu FSB work??

[scottluebke2003]

Athlons are double pumped, and P4's are quad pumped. I know this has to do with the FSB and I understand how you get 800FSB out of a 200mhz bus if it is quad pumped. But what the heck is it really? How do you double or quad pump a FSB??

[Plaster]

dunno, maybe sending two sets of data on both the rising edge and falling edge of clock signals? DDR does one on the rising edge and falling edge per clock signal. Hence double data rate.

[Torlok2002]

ive also wondered this..... any gurus know?

[ATI RADEON 8500]

My guess is mulitplier.

AMD Athlon XP 133 x 2 = 266

P4 Quad pumped 200 x 4 = 800

333mhz barton = 133 x 2.5 (I think)

[Disk11]

Naw, Bartons run @ 166*2=333.

To figure this out, dig out a P4 preview from way back when. Any major review site should still have one.

[Midknyte]

Quad-pumped is where the motherboard chipset has to detect two different voltage levels on both the rising and falling edges of the clock signal. DDR on the other hand only detects one signal on the rising and fall signals.