Hey K,
The KT333 the FSB is 133 mhz.
The Memory bus can be set higher to utilize faster DDR. The CPU runs at 100 or 133 by default, you can set it to run higher, this is the FSB that you are talking about.
In the KT333, there is a option to run the Memory bus at +33 mhz, this will not over-clock the PCI, AGP or CPU, just the DDR. In most systems, yes the FSB is the bus for everything. The KT333 does not change the CPU Multiplier, only the Memory bus. Again the FSB is still 133 mhz, not 166. The Athlon's still only support a 133 FSB, and really cannot make good use of PC2700 DDR's extra bandwidth, so you will not see a big performance gain, until AMD makes a CPU that does support a 166+ FSB, not just Memory bus.
The "Whole Idea" of the KT333, is it is easier to over-clock the FSB. Running a default speeds, there is not a much gain over the KT266A. The KT333 is a chipset for OC'ers & people who want USB 2.0 built on the board(if you need it, it is just as easy to just install a USB 2.0 PCI Card).
Of course, you should not take anyone's word for it, & you should read more real reviews & less community posts on this subject of the KT333 FSB............If I was me, I wouldn't believe me, so why should you?
Peace Out.................tile
god knows your entire system setup & he would answer your questions if he could just stop laughing