Should DDR ram speed match CPU FSB?

Ive got the XP 2400 2Ghz 133x15 with 266MHz FSB

Im looking for more RAM and was wondering what the views are of performance and stability with matching RAM speed and FSB speed.

Eg:
The CPU is 266FSB so currently ive 266MHz RAM (PC2100)
If i keep the CPU and go for 333MHz RAM (PC2700) will things still run ok?

The MOBO can take PC2700, im concerned that the diffirence will be small as things will have to be re-clocked to 266 for the CPU to handle it, could this cause instability?

My other thoughts are that the 333 will mean the data can be found in the RAM faster as the cycle time will be less owing to the higher speed and therefor boost performance.

What are peoples thoughts on this?

Thanks

 

Crucial knows a lot more than I do about these things. You could check their configurator for compatibles.

 

Hi Stuart,

You could install PC3200, it is replaceable for PC2100 (and cheaper now). You won't have to change anything, the PC3200 will automatically run at the speed of your FSB (underclocked). PC3200 and PC2700 is backwards compatible with PC2100.

The only advantage you will have is that you can transfer the faster RAM to machine with a higher FSB in the future (and the cost saving).

Matt

 

bobmc32's suggestion about the configurator is good. They have trialled their RAM on a lot of motherboards. Some motherboards can be fussy about the "type" of RAM, not the speed.

Matt

 

Thanks, all usefull stuff

Im curious, wont "underclocked" RAM not run so reliably?

I was under the impression that the frequency also refreshed the RAM to keep the info stored in it, if its refreshed slower than its supposed to wont there be possible data courruption?

Or is it the case that the data will still refresh at 333Mhz but only be accessed at 266?

 

Having PC3200 would mean that you have more (speed) capacity than you can currently utilise. PC3200 can run at 400mhz (if I remember correctly), your system will only run it at 266mzh. The capacity is there, but you cannot utilise it unless you overclock your FSB.

Running "underclocked" is actually more stable for the system (the only thing that will be underclocked is the RAM that will be underclocked compared to it's "standard" capacity or capabilities). You will just have spare capacity.

Overclocking chips beyond their capacity causes instability. A lot of systems are sold underclocked to ensure their stability. My system was set at 200mzh when I got it, I only set it to 266mzh when I got software that could utilise the extra speed.

I have installed PC2700 on this machine (it runs at 266mzh like yours) it seems as stable or better than when it had the original PC2100. I too could get PC3200 for this machine, it just won't run any better than if it had PC2100 installed.

There should no problems with reliability.

Matt

 

Thanks for that, very interesting about the increasing the stability thing.

Ive meddled with CPU overclocking but the increase is so small without going mad its pointless.

I could almost say that the furtherst i pushed the chip with a friends water cooler 2.75GHz... its was jamming so often things took longer with resetting everything.

Also the chip took a few weeks to recover after it. Its fun but really pointless i think!