Rising and Falling?

[AthlonXP2]

Can someone please explaing that? i.e ddr ram = 133mhz rise and 133mhz fall = 266mhz. What does the rise / fall mean?

Thanks

 

[AndyHui]

For an explanation of DDR SDRAM, please read the FAQ: What is DDR SDRAM.

For an explanation of SDR, DDR and QDR Data transfers, please see the diagram on our Northwood B review here.

 

[Adul]

andy strikes again

 

[new2pc]

I understand the i850E QDR was 100mhz*4 and now 133mhz *4
How does it work for SDRAM? There is DDR (266Mhz)
Will there be QDR for SDRAM? that chip would be i845?

 

[AndyHui]

The pathway between the chipset to the processor, and the chipset to system memory (RAM) are completely separate.

In the case of the i850 and i845(S/D) chipsets, the pathway between the chipset to the processor is 100MHz QDR, or 400MHz effective.

This is independent of the pathway to RAM. For the i850, RDRAM is run at 400MHz; the i845-S runs SDRAM at 100MHz or 133MHz and the i845-D runs DDR SDRAM at 100MHz DDR (200MHz effective) or 133MHz DDR (266MHz effective).

In the case of the i850E and i845E chipsets, the pathway between the chipset to the processor has been upgraded to 133MHz QDR, 533MHz effective.

 

[new2pc]

Thanks Andy.
What about memory?
I am hearing about RDRAM PC800 vs PC1066.
Without PC1066 it still won't take full advantage of the new chip?
Is that correct?
What is the story with SDRAM.

 

[new2pc]

It is confusing.
DDR SDRAM 133*2=266?
Is there a dual DDR SDRAM? 133*2 DUALs?
RDRAM is quad pumped, DDR SDRAM can be dual. Then it would be same.