I called Intel's customer support: 1-800-538-3373.
The guy was nice enough, but at first spoke to me like a total idiot. I told him I have a P4 2.8 Celeron-D w/533 built-in bus.
I asked him what FSB I'm running at. He asked what type of ram I used, and told him ddr400 (I deliberately didn't say pc3200; sounds too technical. I may be confused, but I'm not an idiot, and wanted him to explain to me things in simple terms.) He said then I'm running at a 533 FSB, and to prove it, he directed me to an area in Intel's website to d/l a utility that gives info on the chip. I did, and he directed me to an area in the utility and asked me what I saw. I said "533". "Voila!" he says.
So I said, now wait a minute, are you telling me my SYSTEM MEMORY is 533? (tipoff that I wasn't a total dope.) Pause. Then he starts talking all techno-geek stuff; either to make me shutup and go away, or attempt to further confuse me. He also added he was A+ Certified. Whoopdeedoo.
So I say, look, I know my *system* memory is now 133 Mhz. Using DDR ram, effectively doubles that, can we agree on that? He says yes. So I say, your current P4s send 2 instructions per clock cycle/apparently *2* busses, and in conjuction with ddr ram, that's where Intel's "quad-pumping" gives you an EFFECTIVE FSB of X speed, depending on the built-in FSB of the P4s, using 4 as a multiplier of the system memory. He says he never heard of quad-pumping! I suspect Intel doesn't like the term anymore, so he was denying any knowledge of quad-pumping. Then he says a motherboard has many different types of busses. I said, yes, I know, the pci, agp have busses, but I'm talking about the SYSTEM BUS, the fastest bus that communicates with the cpu (I think he finally realized I'm not totally brain-dead.)
Then I say that we've agreed that ddr ram effectively doubles the system bus, in my case, 2 x 133=266. Then I ask can we agree that Intel P4s sends 2 instructions/clock cycle (he said he didn't know anything about 2 busses), effectively doubling the system bus. He says yes. Then I say for the sake of simplicity, to determine my FSB I simply multiply 4 times the system memory, correct? So 4 x 133= ~ 533, which is, for all intents and purposes my FSB. I don't know why he sounded so reluctant to respond, but he finally said, yes, I'm correct. I think Intel doesn't like the terms "effective", "quad-pump", and not once did the guy mention AMD- he said "another manufacturer", lol. And it was he who mentioned "the other manufacturers" single bus.
So tell me I've finally got it Ray! And to Newbie, apologies if I've seemed to have hijacked your thread. I'm hoping both of us can learn something from this. And for further clarification, I'm speaking ONLY about Intel P4s, NOT any flavor of AMD, nor dual-channel memory.