My brother is running an Athlon 800 on one of the original A7V boards. So, his FSB is 100(200). The bios offers the option of clocking the memory at either 1 or 4/3 of this speed. Since he has PC133 memory, it's set to 4/3. But, someone argued that unless the FSB is running at 133 as well, this won't make any difference at all. Why do they offer this option if it has no effect? Can anyone offer the truth on this matter? Thanks!
His memory will run @133 all right. This will make for a very small performance gain. His fsb runs at 100 Mhz, but due to the DDR interface, performs like a 200 Mhz one, making it possible to take advantage of the 133 Mhz RAM.
However, VIA KT133 chipset take a performance hit when running fsb and memory busses out of synch, almost anihilating any performance increase 133 Mhz memory would offer. Run some benchmarks, and judge for yourself. If your memory can handle 100 Mhz CAS 2-2-2, its probably faster than 133 CAS3..
---- Owner of the only Dell computer with a AMD chip