What's the deal with FSB and Memory?

[Eucharistadorer]

I want to buy faster memory, I currently have 400mhz. But, I was reading that memory should be equal ratio to the fsb. What is the importance of doing this? If I go by this, shouldn't I only buy 533? I was thinking of getting 800mhz, because of the higher bandwidth. But don't want to if there will be a performance decrease because it isn't running 1:1 with the fsb.

Even if I don't intend to oc, will 800mhz still give me better performance than 400 or 533? My current mobo doesn't officially support 400 or 533, but for some reason my 400mhz is working, but I'm experiencing a decrease in performance. So I don't know......

I'm so confused, what should I do? Someone please give advice. Any and all is appreciated. Thanks

(system in sig)

 

[Groveling_Wyrm]

Your processor is running at 266 Mhz FSB (266*9 = 2.4Ghz), while your memory, when set to run at same speed, is DDR ram, effectively making it 266*2 = 533. To run 1:1 ratios, you would need at least the 533.

However, the best performance for running ratios other than 1:1 means that you need to step up your memory timings to around the 400 Mhz mark. Thus, you would want the DDR2 800 ram (400*2=800). If you overclock, then this will give you greater flexibility in memory speeds and timings, and gives less risk of burning out your memory while overclocking.

You won't go wrong by getting some decent DDR2 800 memory.

 

[Eucharistadorer]

Even if I don't oc, I'll see a performance gain. Does a latency such as 3 have any advantage with a core 2 duo?

 

[Eucharistadorer]

I take it that fan works with all ram? How much of a performance gain is there from 400 to 800, or 533 to 800?

 

[EXT64]

Here is an Xbit article about Core 2 Duos and DDR2. Its a little old and a little confusing, but it may help:

http://www.xbitlabs.com/articles/memory/display/core2duo-memory-guide_4.html#sect0

What I got from it was you still will see signifigant increases with 800MHz or 1066MHz ram even with a bus of 266 because the latency will reduce dramatically. I would recommend some Corsair 800MHz ram (low latency).

 

[Eucharistadorer]

What exactly is considered low latency?

I was thinking of this, but someone told me the cas of 3 won't help with Intel cpus: http://www.newegg.com/Product/ProductReview.aspx?Item=N82E16820227190

 

[ryanthesav]

hahaha

 

[Groveling_Wyrm]

Eucharistadorer....that OCZ ram would set you up quite nice. It even has very good latencies. Nice choice.

It is technically correct that CAS 3 won't help much, but there still is a mark of improvement.

 

[Eucharistadorer]

What's so funny ryan?

Anywho, would it be worth the extra 40 to get that instead of 6400 cas 4?