How to calculate your memory frequency
Memory Frequency = (FSB x (CPU ratio)) / ] ((CPU ratio) x (FSB : DRAM ratio)) [
Ceiling function is shown with ][,
eg
]10.1[ = 11
]10.2[ = 11
]-6.2[ = -6
]-8.9[ = -8
For positive numbers always round up to the nearest whole number.
For negative numbers always round down (its actually still up) to the nearest whole number.
Big example
FSB = 290
CPU ratio = 7
DRAM:FSB ratio = 5:6, re-arrange to 6:5 (FSB : DRAM)
Using the formula,
Memory Frequency = (FSB x (CPU ratio)) / ] ((CPU rato) x (FSB : DRAM ratio)) [
Memory Frequency = (290 x (7)) / ] ((7) x (6/5)) [
Work this bit out first
] ((7) x (6/5)) [
6/5 = 1.2
and that becomes
] (7) x (1.2) [
7 x 1.2 = 8.4
Now remember the ceiling function, ][
]8.4[ = 9
Put that back into the main formula
Memory Frequency = (290 x (7)) / 9
So
Memory Frequency = (290 x 7) / 9
= 225.5Mhz.