Basically, the PCI clock runs at FSB (Front Side Bus) speed with a devider. So a machine running 100 Mhz FSB runs the PCI bus at 100 / 3. If you boost the FSB to 145 and don't change the PCI clock devider, you are running the PCI bus at 48 1/3, way out of the 33 Mhz spec for PCI devices and some of them will likely flip out and not work.
As you increase the FSB speed, if your mainboard allows you can increase the devider the PCI bus uses. 145 / 4 is 36 1/4, a number MUCH closer to design speed for your PCI devices. Hence, as you push your FSB speed up, you should up the PCI devider to keep your PCI bus as close to spec as possible.
In the case of your board they do the math for you. You can select a combination of memory speed, FSB speed, and PCI bus speed. I think they are saying that if you want to run 145 FSB, you need to pick the slower RAM bus timings to get a lower multiplier for your RAM speed so you don't drive it to hard. It seems to imply that at 133/133/33 if you push the FSB to 145 your RAM speed won't de-couple and you'll drive your RAM too hard. If you have some really good CAS2 capable Corsair or Mushkin Ram, you might get away with it.
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Lephturn - Chief Trainer
A member of The Flying Pigs
http://www.flyingpigs.com "A pig is a jolly companion, Boar, sow, barrow, or gilt --
A pig is a pal, who'll boost your morale, Though mountains may topple and tilt.
When they've blackballed, bamboozled, and burned you, When they've turned on you, Tory and Whig,
Though you may be thrown over by Tabby and Rover, You'll never go wrong with a pig, a pig,
You'll never go wrong with a pig!" -- Thomas Pynchon, "Gravity's Rainbow"
[This message has been edited by Lephturn (edited 01-15-2001).]
