FSB and memory

[euphoria651]

If i buy an AMD athlon XP2400+ CPU, it only runs at 266mhx fsb right? and if this is the case and i buy 2*256mb DDR400 memory sticks to run in dual channel does this mean that the ram will only run at 266mhz as well i.e pc2100?

Judge me all you want; just keep the verdict to yourself!!!

 

[Crashman]

the 266MHz you refer to is a DDR number representing actual clock cycles of 133MHz. You COULD run your RAM assychronously, faster than the CPU bus, but that doesn't help much (and sometimes causes enough system overhead to offer worse performance). Dual Channel doesn't help much either, but will give you a very slight performance advantage (ie, unnoticable to you, but a few extra points in benchmarks). Since it is an advantage, you might as well use it. And your DDR400 would likely be able to run at SUPER low latencies at DDR266 speed, which WOULD give you a nice performance increase.

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[euphoria651]

So DDR 400 will only perform better because it runs at a lower speed and not "maxed out"?

Judge me all you want; just keep the verdict to yourself!!!

 

[Crashman]

No. But DDR 400 Cas3 would likely run at Cas2 if underclocked to PC2100 speed. And Cas2 provides quicker response than Cas3, so running it at Cas2 would make it perform better than Cas3 PC2100.

Of course you could buy Cas2 PC2100, but that wouldn't leave you any room to overclock your CPU, and your memory would be useless if you ever upgraded to a CPU with a faster bus speed.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[euphoria651]

Forgive a noobie question. What is Cas2 and Cas3? is there Cas 1? i have never heard of anything like this

Judge me all you want; just keep the verdict to yourself!!!

 

[Crashman]

I think there's information on this in the first post of this forum.

Cas Latency is the number of clock cycles it takes the memory to respond. The only RAM on the market is Cas2 and Cas3, but some Cas 3 runs mixed with Cas4 timings. YOu should look at that first post.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[addiarmadar]

If you keep the clock speed at 133 then the ram will do 133 in dual channel mode.

F-DISK-Format-Reinstal DO DA!! DO DA!!

 

[vagabond]

Hey Crashman,

Just read this thread and seeing that my system is "in sync"

would it be worth it to buy DDR400 for my system??? Plan on upgrading mobo and CPU in the near future.

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<b><font color=blue>VAGABOND<font color=blue></b>

<b><font color=blue>Just horsing around!!!<font color=blue></b>

 

[Crashman]

If you think you'll be moving up to 200MHz FSB (either by upgrade or overclock), I'd get the DDR400. It works with most DDR boards.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[vagabond]

OK. Thanks.

<A HREF="http://www.anandtech.com/mysystemrig.html?id=23810" target="_new"><font color=blue>My System </font color=blue></A>
<b><font color=blue>VAGABOND<font color=blue></b>

<b><font color=blue>Just horsing around!!!<font color=blue></b>