I have 3 sticks (2 -128, 1 - 64) sticks of Micron PC 133 8 ns in my two systems. I have one 128 & the 64 mb in my asus P3V4X in 'auto' setting & when I overclock my CPU to a 146 mhz bus, I am able to run my memory at 1/1 (i.e. it runs at 146mhz). I don't know much about this CAS stuff, but the memory will clock higher than my P3 550e (I know its either the CPU or my Geforce ddr & not the memory holding me back, since if I set my memory at -33 I still can't get above a 146mhz bus).