View Full Version : overclocking cpu with memory 1:1 devider

11-18-05, 08:51 AM
hello dudes, i own a a8n-sli mobo...and pc4800 ddr.. one quick question... how do you overclock the mempry and cpu to be 1:1 ? every time i change the ddr settings to like 433...or 500..etc..it doesnt stay..then when you go to jumperless setting..and change the cpu memory frequency..it doesnt stay the same as configured with ddr setup menu...how the **** do u get a 1:1 of 500 ddr???

sorry for my ignorance on this subject...


11-18-05, 09:38 AM
if you want to keep a 1:1 divider, you must keep your ram speed set to DDR400 (1:1).

other dividers are calculated simply. for example, a speed of DDR333 would be (200/6)*5=166.6... therefore it would be a 6/5 divider. there are some resources online available you can look at that will tell you the respective divider for each speed setting.

note that although this may seem the same as pentium and athlonxp oc'ing, it is different, as the memory speeds are determined by a CPU divider (usually your CPU multiplier) because your FSB is your hyperthreading bus, which operates at 1000MHz (2000MHz effective, up and down-streams)

however, since youre interested in only the 1:1 ratio, just use the DDR400 setting and increase your HTT bus speed (default is 200). also, remember to lower your HT multiplier. when doing this, try to get the speed of the hyperthreading bus as close to 1000 as possible. this is done by multiplying the HTT bus times the HT multiplier. for example, my HTT is run at 250, with a memory divider of 1:1 (the DDR400 selection), and my HT multiplier at 4x, so 4*250=1000 ;)

if you have any questions, let me know. didnt mean to treat you like you didnt know what youre doing, just like to put as much useful info into these things as possible because it took me a while to figure out how to OC these boards/processors, hehe. good luck :)

EDIT: one more thing, make sure you force your CPU multiplier to the value you want (usually 9-12, if you have an FX you can set it to any value). the board wants to set the chip at its default speed, so it will lower your multiplier to make that happen, which is not what you want.

11-18-05, 10:42 AM
Yeap you need to force it at 400MHz thats 1:1 also only use whole multipliers. 10.5 etc are not real what it does is either overclock the FSB with a lower multiplier or increases it and reduces the memory clock. But it will show as a 10.5 multiplier still. It's some thing has has been happening since the A64 has been released.

11-18-05, 02:31 PM
thanks a bunch man...ill try it when i get home tonight