Definitely. Minor/major changes in programming, component batches or even chip brands happen on likely a weekly basis -- this is a very fast-moving industry, so any reviews of RAM need to be read with the understanding that it is unlikely that you will be able to get those specific modules, especially if the review is more than a month old. Thus, overall brand reputations become more important; detailed questions about what specific chips are in currently-shipping modules may also help.
The first thing to do is to figure out what FSB clock speed you want to reach, then use that to figure out what RAM speed you will need to saturate the FSB's throughput. Assuming you are going with a 1066MHz data rate C2D CPU, FSB clock speed is 266MHz, and DDR2-533 RAM speed will saturate it (assuming you are running in dual-channel mode). As you boost the FSB clock, you'll want to run the RAM correspondingly faster; sounds like a 400MHz FSB clock (DDR2-800 RAM speed) would be a reasonable upper limit for you.
This is my 2nd attempt at OC'ing and I still consider myself a novice.
I think I understood what you said above. You would deliberatly underclock your 800MHz mem to 533, so the memory can handle the highger FSB. Shouldn't be too hard to find that in the Bios.
I guess I should give you more info: my goal in overclocking is to squeez some more speed out of a fast system. Not that I really need to, but just to see if I can do it.
I'm looking at C2D, prolly a E6600 after the price drop. Everyone seems to love the E6300 for OC'ing, but I want to still be fast even if I have limited success.
I havent decided on a mobo yet. The DS3 seems like a good option, but the revisions are confusing. Biostar's TForce maybe. Passive cooling for the N/S bridge is a must. Would 400MHz FSB be safe using a value mobo with cheap HSinks like those?