DRAM 1:1 ratio, and bus speed

[bennythyer]

asus m4a78-e
AMD phenom 9950 BE 2.6stock
4GB kingston (2x2GB) 1066mhz DDR2-PC2-8500

i have my cpu overclocked to 2.9ghz with bus 231mhz and multiplyer 12.5

so get that i have DDR2 924MHz ram, and it says 12:6 DRAM:FSBUS frequency, how much better is 1:1 ratio is it faster or just more stable?
i have tried incresing my bus speed from 231 upwards but only really gets to 235-240 then says overclock failed (even with lower cpu multiplier) why is this is it something to to with ganged and unganged mode? or is it just the limitation i have with my mobo/ram or what?
and if i were to do 1:1 ratio at my current bus speed it means i only get 462MHz ram which is slow no?

 

[amnotanoobie]

Technically your overclock is sound, as you could divide the Memory speed by the bus and you get a whole number.

462MHz (actual ddr speed) / 231MHz (FSB) = 2

 

[bennythyer]

Technically your overclock is sound, as you could divide the Memory speed by the bus and you get a whole number.

462MHz (actual ddr speed) / 231MHz (FSB) = 2

Technically your overclock is sound, as you could divide the Memory speed by the bus and you get a whole number.

462MHz (actual ddr speed) / 231MHz (FSB) = 2

yea but isnt 462 slow for the ram? it can be clocked up to 1066??

 

[amnotanoobie]

Trouble is, I have little clue about overclocking AMD processors. I might recommend increasing the vcore, or ram voltage or you might try "relaxing the memory timings" (set them to higher numbers).

If it yours was an Intel system I might recommend increasing the fsb voltage, but amd has long dropped the FSB and has hypertransport in place, and tweaking that part is one thing I know nothing of.

 

[curtains]

1:1 ratio should be faster if running at the same RAM speed

Think of it like this, Bus = highway/motor way ratio = lanes merging.

12:6 = 2:1 is kinda like the highway havng 2 lanes merge into 1 lane.

1:1 is just a straight high way no lanes merging meaning every car gets its own lane.

But in your case your 1:1 is nearly half the speed of 2:1 its like saying, all your 'cars' get there own lanes, but they can only go 30mph on the highway.

I'm quiet sure the 2:1 would be faster.

They should both be as stable as each other anyway

the overclock failure could be to do with the CPU it self (i haven't overclock a AMD processors in years) or Motherboard limitations. You could try increase the voltage of the CPU (though this will decrease life span of your CPU a little if thats not a problem for you)