Dividers on DFI boards

[K404]

At the moment, this only holds true for the DFI Award BIOS

I stumbled onto this by accident when I was overclocking on a divider. I dont know if this is something everyone knew (except me) and just didnt talk about but here we go:

I`d been using a calculator to figure out the sweet spots between RAM and CPU speeds.

I was finding that if I put my RAM on a divider, it wasnt bringing up the same values as what I expected..e.g...

300x9 on a 166 divider... I was expecting to see 166/200 x 300 = 249MHz on the RAM. I was getting 245.5 Not a massive difference here, but the gaps can be pretty big.

We know that CPU speed= HTT frequency x multiplier. for 1:1 memory, the CPU frequency is divided by the multiplier again to get the RAM frequency, when you put the RAM on a divider, the CPU speed is divided by an increased number to get the RAM frequency.

SO (so far).... 1:1, RAM= CPU speed/multiplier

180 divider RAM= CPU speed/multiplier+1

166 divider: RAM= CPU speed/multiplier+2 e.g... CPU speed=2700 (300x9) a 166 divider puts the RAM on 2700/11 = 245.5, which is what it is.

150 divider RAM= CPU speed/multiplier+3

to be continued...if anyone really wants to try this on other mobos, be my guest and I can add the info.

Kenny

 

[BigAndy]

As you started talk about dividers i would like to ask you a bit help .

I'm tried to get my CPU frequency 2.55-2.65 GHz (to be more precise i was after 2.6 GHz) and memory frequency 275 MHz. To calculate settings i was using A64MemFreq11 utility wich you can get from http://xtremesystems.org/forums/showthread.php?t=44339&highlight=A64MemFreq+1.1. I spend about 2 hours trying get my memory run at 275 MHz and CPU at 2.60 GHz or at least around 2.6, but looks like it's mission impossible. If i could get memory correct then CPU was raning with wrong frequency and if i could get CPU at correct frequency then RAM was wrong... Look's like there is impossible get numbers like 2.60 GHz CPU + 275 MHz RAM .

So, if you doing any calculations and if you come close to correct settings for frequency's i'm after could you let me now, please .

Cheers

 

[sacha35]

Hi this is a handy littel tool which does all the hard work for you just type in the speeds and it works it all out.

http://math.gogar.com/athlon64.cgi

 

[BigAndy]

Hi this is a handy littel tool which does all the hard work for you just type in the speeds and it works it all out.

http://math.gogar.com/athlon64.cgi

Cheers

Handy tool, but it's proved that it's impossible to get combination 2.60 GHz CPU + 275 MHz RAM .