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CaptNKILL
06-29-05, 04:30 PM
Ok, Iv'e been fiddling with my overclocks lately (mostly because its been 95 degrees here every day for the past week but I want to keep my computer up to speed to play BF2) and Im a bit confused about something.

In my BIOS I have memory "speeds" of 200\166\133\100... and I know they equate to dividers, but how do I know what they are?

It seems like CPUZ and Sandra show totaly different memory speeds than my BIOS does, and niether really work out to the memory dividers that I figure (ie 280fsb with a 166 divider gives me 233Mhz memory in the BIOS... which doesnt figure correctly at all).

Can anyone find me a concrete (ie, official) list of what these memory dividers mean?

For example, setting a divider of 133 should be 2/3 (133/200)but when I set this in my BIOS its FAR from a 2/3 ratio of my actual FSB. Whats really strange is that in CPUZ the ratios are shown as a ratio of the CPU speed, not the FSB. Ive seen it say "CPU/11" or "CPU/14"... and that seems to come out correctly with the speeds reported in CPUZ and Sandra, but it doesnt really help me with overclocking since these speeds arent shown in the BIOS.

Im kinda lost, so if anyone has any info, I need to know what these dividers are:
200 (1/1 afaik)
166
133
100

Thanks.

Also Im curious as to why I cant set my FSB real high (like over 300) even after setting the memory divider, CPU multiplier and HTT multiplier lower. Id like the extra options that 300+ FSB provides, but it just doesnt work for some reason. Is the chipset being stressed? If so, how? I thought the FSB was integrated onto the CPU with socket 939 system.

Lfctony
06-29-05, 10:30 PM
It does seem correct to me. The default FSB is 200, 280 is 1.4 times that. 233Mhz is 1.4 times the 166 value you set in the bios. I think the numbers do add up.

Dividers are 1/1, .83, .66, .50.

CaptNKILL
06-29-05, 10:41 PM
It does seem correct to me. The default FSB is 200, 280 is 1.4 times that. 233Mhz is 1.4 times the 166 value you set in the bios. I think the numbers do add up.

Dividers are 1/1, .83, .66, .50.
Ah I see... I was doing something backwards. Thanks ;)

EDIT: Any idea why the BIOS would show different speeds than Sandra and CPUZ? Like when I do it the way you did I get 233Mhz, and thats what the BIOS says, but Sandra and CPUZ were reporting something like 224Mhz. And thats what I would get when I did it my way (which was wrong apparently). What I was doing:
280 x 4\5 = 224

I wonder why they do it differently :confused:

Lfctony
06-29-05, 11:25 PM
I have no idea why there's a difference, I always do my calcs manually so... :) Maybe someone else can shed more light on this.

watever
06-30-05, 03:10 PM
hmm i get problems with the memory dividers and cpuz/sandra also. When i set my fsb to 240, giving me a cpu clock of 2.64 ghz, and i set my memory to 166, i should get a ram clock at 200 mhz. Cpuz and sandra both show the ram at 182 mhz. But if i up the fsb to 255 with a 10x multiplier, giving me a cpu clock of 2.55.. cpuz/sandra shows the correct ram clock of 212. I have no idea why it doesnt show the correct ram speed when i use the x11 multiplier.... I think ill just invest in some better ram so i can do a 1:1 ratio.