which it is the native frequency of the ram of R51?

[Nicola]

to how many mhz the ram works of the R51?

[aaa]

http://www.thinkwiki.org/wiki/Category:R51

It's PC2700.

[Nicola]

the frequency of the ram depends on the bios or the cpu?

I acquire a R51 with Dothan and pc2700, then I replace with Banias, the ram works to 133 or 166 mhz?

[Harryc]

Both a Dothan and Banias run at the same 400MHz FSB in an R51. At any rate that has nothing to do with memory bus speed. It is a constant 333MHz = PC2700.

[rkawakami]

Actually I believe that the memory system timing is determined by the chipset installed in the system and not by either the BIOS or what CPU you have. This is usually referred to as the "northbridge" or front side bus (FSB) clock rate.

ref: http://en.wikipedia.org/wiki/Front_side_bus
http://www.oempcworld.com/support/fsb.htm

[Nicola]

Thanks but all these things I know to them well.
I want to know the frequency of the ram in the notebook Centrino. I have used vary sw and nobody of these says it.
Why?
I would want to have a bus sincrono, I would want to lower the frequency of the ram to 100 mhz.

The thinkpad with Dothan mount ram pc2700 (166 mhz).
The thinkpad with Banias mount ram pc2100 (133 mhz).
Why?
Only for commercial reasons?

If effectively they work to two different frequencies, where the speed is set up?
In the chip-set is written Banias=133 and Dothan=166?

[aaa]

It has nothing to do with Banias vs Dothan. The cpu does not decide the ram speed, the chipset and motherboard do.

The older Thinkpad motherboards like in the T40 only allowed PC2100, I'm not sure why. By coincidence, the processor being sold back then was the Banias. Then you have the T41 and the R50, with allowed PC2700 and came with a Banias. Then there's the T42 and the R51, also PC2700 but with a Dothan.

I'd like to understand why you want the FSB to be synchronized with the ram. I don't think there's a performance benefit, otherwise Intel would have done it.

[Nicola]

I have read of recent that there are two versions of chip-set. The first supports ram only the 266, the second also ram the 333.
Both call 855pm.
Also chipset the 855gm but the first is called therefore, the second 855gme.