"Outside Os" overclock vs "Inside OS" overclock

Why the hell, my computer don't boot with memory limited to 200, (it boots with memory to 160), and don't boot with fsb to 230, and in windows i change the fsb to 250, and the memory limit to 200, and it keeps running normally?

MSI, in all their infinite wisdom, will not let you set the mem clock greater than what your memory stick SPD says it should be. I had a frustrating time with my PC2700 BH5 sticks because of that limitation. Even though they ran 200 2-2-2-6 the BIOS would force me to use 166 because that's what the SPD said they were supposed to be. Open CPU-Z and look at your memorys SPD. If it's PC2700, you can set the memory to 200 Mhz, but it will disregard your setting. Interestingly, with the memory divider set to 166 ( aka 5:6 ), it will run the memory faster than 166 if your CPU FSB is set for more than 166. For example, I was running my setup at 10x240 5:6 and the memory actually ran at 200 Mhz. I also could run it at 9x300 2:3 and the memory ran at 200 Mhz.

So, think of those memory clock settings as actually being dividers, not absolute frequencies. 200=1:1, 166=5:6 and 133=2:3.

Hoot

you are running out of the point from wich i create the post.
The question is simple:
Why the computer don't go to the OS with some setting, and if change it in windows it keeps running?
(even not talking of memory but talking of processor and fsb)