Newbie q: Memory clock vs. FSB speed?

[JoeDHill]

Hi,

Is there any point to getting memory that cycles faster than the front side bus of the mobo (i.e. DDR333 vs a 266mhz bus)? I know memory is backwards compatible, but is there any hit to performance by having faster memory than the FSB? I seem to remember reading here that there was because the memory had to wait until the CPU was ready, and the lack of synching actually drug things out a bit, but I can't find the article. It turns out that the faster memory I'm looking at is cheaper than the slower (supply vs demand reasons?)
Thanks in advance, this has really confused me.

 

[bum_jcrules]

Because you are new I'll give you a break. Please do a search next time. Crashman and I have both gone into depth into this issue.

Thanks!

"Is there any point to getting memory that cycles faster than the front side bus of the mobo (i.e. DDR333 vs a 266mhz bus)?"

Not really. The memory bus will be bottlenecked at the FSB.


"I know memory is backwards compatible, but is there any hit to performance by having faster memory than the FSB?"

Yes there will be some gains over a 1:1 vs a 1:1.25 (FSB to memory) ratio between the two buses. (Maybe 1-3% max. depending on the system.) This is because the FSB is not waiting on the memory bus nor is the memory bus not ready for the next command sent from the FSB.

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[JoeDHill]

Sorry; I actually did search, but apparently didn't do it well enough. Thanks for the reply; I'll search under your name for the earlier discussion.