how's this possible?

[Guest]

how's is possible that a CPU can have a different bus speed then the RAM? For example, the atholon CPUs run at 266Mhz bus but they can still co-exist with the new 333Mhz DDR-RAM. how's this possible? where's the line drawn that enables this?

 

[FatBurger]

At the memory controller/Northbridge, basically. And KT333 chipsets don't run the RAM at 333 by default, you have to overclock it to that.

<font color=blue>If you don't buy Windows, then the terrorists have already won!</font color=blue> - Microsoft

 

[AMD_Man]

They run it asyncronously. However, AFAIK, the RAM is not independant of the Northbridge and so it's effective peak performance is still 2.1GB/s. However, every cycle on PC2700 takes 6ns rather than 7.5 ns so at CL2, you'd have an effective latency of 12ns instead of 15ns everytime you access the memory. Therefore the computer can still benefit from PC2700.

<b><i>"A penny saved is a penny earned!"</i></b>

 

[FatBurger]

AFAIK, the RAM is not independant of the Northbridge and so it's effective peak performance is still 2.1GB/s.

You mean that even with OCing you can't get actual 2.1GBs? If so, then that's not true, since I get just over 3.2GB/s in Sandra with my PC800.

<font color=blue>If you don't buy Windows, then the terrorists have already won!</font color=blue> - Microsoft

 

[siliconjon]

CUz it's a PC...everything in it can run at different speeds (and usually does)...it's black magic.


DIM POST, STUPID
POST = INPUT $X
STUPID = PEEK 420, 255
IF POST >= STUPID, THEN GOTO H3LL