How does RAM speed affect the C2D?

[Devonavar]

Ok, ok, I know I'm behind on the times for CPU performance, but hopefully you guys can answer this.

I know that C2D is supposed to kick the pants off X2 parts, even when cost is factored in. My question is, where does RAM fit into the equation?

I would assume that most C2D tests have used PC-6400 RAM, since that's supposedly what's recommended, but I notice that this fast RAM is a) hard to find and b) twice as expensive as PC-4200.

My question is this: Does the C2D maintain its performance advantage with slower PC-4200 RAM, or does it require PC-6400 to really knock the socks of the X2? From a cost-benefit perspective, do I need to spend that extra $200 on RAM to get a C2D system that out-performs the X2?

Put another way: If my C2D system is running PC-4200, can I build an X2 system with similar performance for cheaper?[/b]

[accord1999]

Ok, ok, I know I'm behind on the times for CPU performance, but hopefully you guys can answer this.

I know that C2D is supposed to kick the pants off X2 parts, even when cost is factored in. My question is, where does RAM fit into the equation?

Memory speeds has some impact on the performance of the C2D, see here:

http://www.xbitlabs.com/articles/memory ... ide_6.html

But the X2 suffers more from slow memory. It typically needs DDR2-800 just to beat DDR1-400 and the drop-off from DDR2-800 to DDR2-533 is higher than the C2D's drop-off from DDR2-1067 to DDR2-533.

http://www.xbitlabs.com/articles/cpu/di ... m2_13.html

The C2D even with slow DDR2-400 will beat X2 with DDR2-800, even in latency sensitive games:

http://www.anandtech.com/memory/showdoc.aspx?i=2800&p=7

[Tzupy]

As long as you don't overclock, the best memory performance on C2D is with DDR2-533 (1:1 FSB / memory ratio) at the lowest possible latency.
Since such DDR2-533 memory is not available, using a DDR2-667C4 or DDR2-800C5 as DDR2-533C3 (low latency) is the way to go.
I must say that I was too lazy to try this myself yet (I have 2X1 GB DDR2-800C5), but I read about it.

[nick705]

Another article at Madshrimps - bottom line, unless you're overclocking you might as well stick with DDR2-533 and save your money.

[Devonavar]

Thanks, that's pretty much what I thought, but I had forgotten a few of my RAM basics when I posted. I've figured things out now.

[speedlever]

Another article at Madshrimps - bottom line, unless you're overclocking you might as well stick with DDR2-533 and save your money.

Is it just me or do memory prices at the 'Egg not show much difference between DDR2-533 and DDR2-800 RAM?