AM2 coming, it's time to learn some DDR2 stuff!! NEED help!!

[sam1]

Hi there. I ll cut it straight in. DDR2 offers more bandwitch but at the cost of high latency. From what I know, 2-2-2-5 seems to be the lowest timing for DDR400. 3-3-3-8 seems to be the moderate timing for many modules. If I'm buying an AM2 system in the summer I intend to buy DDR2-800 modules, preferably 2GB in dual channel. Can someone answer the following questions please:

1. What are the lowest timings for DDR2-800,667, and 533?

2. What are the moderate timings for DDR2-800,667, and 533?

3. Since DDR2 memory modules run at considerably higher speeds, will this make overclocking easier?
a. Will I need dividers such as CPU:RAM = 3:4 (300MHz HTT : 400MHz memory)?

b. If the bandwitch is already high enough for AMD CPUs, can I leave the modules running on SPD and use dividers such as 9:10 (300MHz HTT : 333MHz memory)? (So I will only need to worry about OCing CPU).

4. I found out that buying 2 exact modules is cheaper than buying a dual channel kit, so why buy dual channel kits?

THANKS!

 

[The_Prophecy]

1. Lowest i've seen are:
3-2-2-8 (DDR2-533)
4-2-2-8 (DDR2-667)
4-3-4-8 (DDR2-800)

2. moderate are approximately:
3-3-3-8 (DDR2-533)
4-4-4-8 (DDR2-667)
5-5-5-10 (DDR2-800)

3. OC'ing in theory would be no easier or more difficult than with ddr1... you're just dealing with higher frequencies

4. Because the 2 of the same module may not allow for dual channel operation. I noticed this once while working on a friend's computer... 2 sticks, same size, same rated speed on a board that said it supported dual channel ram, but i couldn't get them to run in dual channel mode.

anything i didn't answer... i left out intentionally because i'm not positive about the answer.

 

[The_Prophecy]

now that i really think about it..... prozac is right.

 

[IcY18]

in this test provided by Tom, they show that the High Clock Frequencies will most likely beat out Tight Timings but only about a 5%, http://www.tomshardware.com/2006/03/31/tight_timings_vs_high_clock_frequencies/page10.html

lastly if my information is correct AMD stuck with DDR because they could have tighter timings which AMDs are much more sensitive to for performing better, rather than on an Intel where they went to DDR2 with high frequencies and slower timings b/c they weren't as sensitive to the timings as AMDs are...so in the case of AMDs lower timings would be better i think

 

[yourmothersanastronaut]

There isn't really too much of a real-world benefit - all this is in theory. CAS4 vs CAS3 won't really change your FPS all that much, nor would DDR2-800 vs DDR2-667. The only changes will be in memory bandwidth benchmarks. Your FPS won't change drastically - it's more the amount of RAM you have.

But it's ballsy to get the super high-end stuff...