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Big Fat Duck

I still cant grasp how memory dividers work

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i've read THE DEFINITIVE GUIDE of overclocking but i still dont understand why this is happening

 

i have my fsb as 240 and my multiplier as auto (x11) and then my memory, which i heard doesnt overclock well, is on a 5/6 divider. why does cpu-z report my ram frequency as 188.6 mhz when 240 x (5/6) is supposed to be 200 mhz ? I know there is some concept i am missing but i seriously cant figure out what it is on my own..

 

i tried the 9/10 divider, but that gave me a blue screen.. so im guessing the frequency was too high for the selected timings....

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I want to know too... running at 264 mhz with 3/4 ratio and ram is nowhere to be as the equation tells me it should.

 

I think it is how the CPU memory controller works, as I have seen the same problems with the Asus A8N SLI Deluxe... it could be normal, since its a miracle we can run asynchronic mode.

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AFAIK it's to do with the multi you use on the cpu.

 

When I run 5/6 I find that at 300x9, the ram runs at 245MHz, and at 300x10 it runs at 250MHz.

I haven't a clue why it does so, well I have a clue, it's to do with the cpu multi ;), but I just accept it as a given.

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Well one thing for sure is how 11 x 264 @ 3/4 with ram @ 2.6v I get no memtest86 errors.... however, it doesn't load windows with out a BSOD... unless ram gets 2.8v. Also its a fact that if I increase the frequency to 11 x 272 and keep the 3/4 ratio thinking the RAM will clock to its normal DDR400 speeds, Prime95 and SuperPi find errors right away.... yet, sometimes they don't...

 

Btw, nothing of this happens if I run 1:1 with the Platinum Rev2 or the XMS4400C25... which only makes this ratio thing more of a mistery :sweat:

 

Evil spirits, bad medicine... espiritus chocarreros!!! :rolleyes:

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A64memfreq this will take all your guess work out of you and do it for you .Check it out Download the zip file on first post

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also ive noticed for some reason, the more i overclock away from stock 2.2 ghz, the more choppy bf2 behaves, its like the choppiness that someone would experience if they didnt have 2gb ram and ran high settings.. but i HAVE 2gb ram.. wtf....

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A64memfreq this will take all your guess work out of you and do it for you .Check it out Download the zip file on first post

 

ive used that program and it doesnt help at all.. it shows a choice for 183 mhz.. but there is nothing like that on the bios... the closest is 180mhz which is the 9/10 divider that gives me bsod

 

nm i think i have it working

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also ive noticed for some reason, the more i overclock away from stock 2.2 ghz, the more choppy bf2 behaves, its like the choppiness that someone would experience if they didnt have 2gb ram and ran high settings.. but i HAVE 2gb ram.. wtf....

Are you using the latest drivers from nvidia (video)?

 

I think something might be wrong with the shadders in the game... and deleting the folder containing them and creating new ones (new video settings). Could be that, or maybe the ram performance is too low or something.

 

I am at 2.9 ghz with two 6800GT's in SLI and two gigabytes of ram, and I think I have little to no performance gain from running stock...... but sometimes I see low fps when I am near an explosion, same as with slower system speed probably.

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A multiplier works in the following way.

 

you have a FSB or HTT of 200mhz.

 

if the memory divider or multiplier is 3/4. then your memory speed will be as follows:

 

200 / 4 = 50.

50 x 3 = 150mhz

 

since its DDR, double data rate and all that, 150 x 2 = 300mhz DDR.

 

the higher you raise the FSB, you memory might not be able 2 stick at it so a divider is used to reduce the speed in which the memory communicates with the CPU.

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A64memfreq this will take all your guess work out of you and do it for you .Check it out Download the zip file on first post

Tried the little calculator and it works fine... it shows exactly what the RAM frequency is going ot be at certain divider and frequency... yet it doesn't answer why RAM seems to be very stressed at quite low speeds as I explained before; must be a chipset or memory controller limit since dividers feel the same as half multipliers (a figment of your imagination ;) )

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Tried the little calculator and it works fine... it shows exactly what the RAM frequency is going ot be at certain divider and frequency... yet it doesn't answer why RAM seems to be very stressed at quite low speeds as I explained before; must be a chipset or memory controller limit since dividers feel the same as half multipliers (a figment of your imagination ;) )
Well if you dont wont your memory to be very stressed. you have to lossen the timmings.2-3-2-5 are real tight timmings. But it dont matter if you run tight timming on a divider or lose timmings 1/1.Your not going to get 1 GiG sticks to do more then 225 or 230 on them tight timmings

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