CPU Clock Ratio - that will be the multiplier. From what xbit said you should be able to change between 6 or 7, which can be a good thing if you want to oc the FSB more but is hitting the GHz ceiling on the CPU.
CPU Host Frequency - Looks like this is the magic setting that you are looking for. It determines everything from the actual FSB, CPU GHz, and even the memory clock. That will be the "base FSB number" that I referred to earlier.
System Memory Multiplier - at least this made sense to me. May be you are stuck with dividers from HTT in the A64 world, but ultimately it is just the reciprical of dividers. And yes you do need to adjust this. According to the manual, use "host clock" (that should be CPU Host frequency), apply the mulitplier and that will be the memory clock, which is your 533, 667, 800, etc.
Memory Frequency - according to the menu you can't control this one, it is derived from CPU Host Frequency and Memory Multiplier. I suppose you can use this to see if you are overspecing the RAM after you adjust the other 2 factors.
So let's get to some examples. Disclaimer: I may be completely off with this, so feel free to correct me. But the manual made sense to me.
E6300 @ 1.86GHz, DDR2-667 RAM, all stock:
CPU clock ratio: 7x
CPU host frequency: 266MHz
[Resultant CPU clock: 1.86GHz (there are rounding stuff in there so it works out)]
Memory multiplier: 2.5x
[Resultant Memory clock: 667MHz]
E6300 @ 1.86GHz, DDR2-800, all stock:
CPU clock ratio: 7x
CPU host frequency: 266MHz
[Resultant CPU clock: 1.86GHz (there are rounding stuff in there so it works out)]
Memory multiplier: 3x
[Resultant Memory clock: 800MHz]
E6300 @ 2.1GHz, DDR2-800 @ 900:
CPU clock ratio: 7x
CPU host frequency: 300MHz
[Resultant CPU clock: 2.1GHz]
Memory multiplier: 3x
[Resultant Memory clock: 900MHz] (this is kind of like your 1:1 ratio if you must understand it that way)
E6300 @ 2.1GHz, DDR2-800:(I am guessing this is your most likely scenario)
CPU clock ratio: 7x
CPU host frequency: 300MHz
[Resultant CPU clock: 2.1GHz]
Memory multiplier: 2.66x
[Resultant Memory clock: 800MHz] (you can say the divider is applied here)
* this one overclocks the CPU, but keep the RAM at stock, so it is a good thing
E6300 @ 2.8GHz, DDR2-800 @ 1066: (this will be gravy if you can reach that)
CPU clock ratio: 7x
CPU host frequency: 400MHz
[Resultant CPU clock: 2.8GHz]
Memory multiplier: 2.66x
[Resultant Memory clock: 1066MHz] (don't think you can oc DDR2-800 like that, but if you have 1066 memory...)
E6300 @ 2.8GHz, DDR2-800:
CPU clock ratio: 7x
CPU host frequency: 400MHz
[Resultant CPU clock: 2.8GHz]
Memory multiplier: 2x
[Resultant Memory clock: 800MHz] (keeping RAM at stock yay!)
* Conroe looks to be great overclockers like the A64/X2, so more than likely you should keep the RAM at stock and oc the crap out of that CPU
E6300 @ 2.4GHz, DDR2-800:
CPU clock ratio: 6x
CPU host frequency: 400MHz
[Resultant CPU clock: 2.4GHz]
Memory multiplier: 2x
[Resultant Memory clock: 800MHz] (keeping RAM at stock yay!)
* if your E6300 cannot go that high, turn down the CPU multiplier a notch and you are still in business
So the strategy should be like this:
- pump "CPU host frequency", while massaging the memory multiplier to keep the RAM at or near stock
- then you can increase the memory multiplier to see how much further you can oc the RAM
Note on rounding issues: if you are going to work out a spreadsheet on this, derive "266" with 800/3 and let Excel carry over all the decimal places. Then you should be able to reach 266MHz x 7 = 1.867GHz and other magic numbers.