Originally posted by Meithan
Are you sure about this? I thought it was the other way around. For instance, 5:4 would mean that the RAM runs at 80% the FSB, 3:2 would have RAM running at 67% the FSB, etc.
You are correct with that, but what I am saying is that on most newer Intel boards, they do not have downward memory dividers. What you see on these boards is more often the reverse of those dividers (i.e. 4:5 instead of 5:4).
Again, this is do to the current ratio of FSB and DDR2 speeds.
C2D has a FSB of 266. Most people are running DDR2-667 and DDR2-800 on these boards. In order to have the memory run at full speed at stock FSB, the board has "upward memory dividers."
Example: for DDR2-800 to run at full speed at a FSB of 266, it takes a "divider" of 2:3 (not 3:2).