Archived from groups: alt.comp.hardware.homebuilt (
More info?)
On Thu, 20 Jan 2005 00:24:10 -0600, Last Boy Scout
<eggbtr@ezl.com> wrote:
>doS wrote:
>
>> I have a p4 3.06 533mhz fsb. My memory is pc2700(333). In my bios I have
>> option to run memory at 200 or 266 mhz. I assume the 266 would be faster?
>> TIA
>>
>>
>Just because you have a quad pumped processor bus, that has nothing to
>do with the memory.
Not necessarily true. Many boards are faster at sync clock
rate but possibly more stable. I've heard of people who
have a board that can run 333MHz (166 clock, DDR333) memory
bus stable with 4 x 133 FSB, or can run 4 x 200 FSB & memory
(with different memory) but can't run 4 x 200 FSB & 2 x 166
memory bus. Might be a chipset issue, a bios flaw, I don't
know... seldom is it as important to find out why a slower
setting doesn't work.
>Often the memory bus and the processor bus are out
>of sinc. It looks like 200 and 266 are the combined Memory FSB Speeds.
? I doubt it, more likely it's the clock rate (100MHz) x 2
for memory = 200, OR it's the +33 async clock rate of 133 x
2 = 266.
> DDR handles memory twice a clock cycle. So it looks like 200 is for
>PC2100 and 266 is for PC2700. Make sure that is a memory setting and
>not a processor setting.
No, regardless of the rest, 200 is not PC2100, it would be
PC1600 if a single data rate or PC3200 if it's the clock
rate not yet in DDR terms. It doesn't appear to be the
clock rate with a CPU of 133 clock/quad-rate 533. 266 would
be PC2100 if either is.
>
>This is a case where I always wonder what your Motherboard Manual says.
Yes, or leave it at the defaults.