Is running sync always better than async on AMDs?

Hi, I have 400ddr ram, but I only have a 2600+ barton so my FSB is limited to 166. Sure I can overclock it, but I haven't managed to hit 200 yet.

Anyway, what I was wondering is: is it better to run the RAM at 333mhz 3/3 synced to the FSB speed, or async at 400mhz? And if I overclock to say, 185fsb. Will running the RAM again be faster sync or async?

Thanks a bunch!

In-sync is always better.

So even running it only at 333mhz will be faster than running it at 400mhz? How big is the difference approximately?

What is the tehcnical explanation for this?

Sorry for the avalanche of questions

Most likely sync will be better than out of sunc in all cases. The explanation for this is the lackluster ability of the nforce2 chipset to use ratios to run mem out of sync. Its basically a chipset limitation problem. There are certain instances I'm sure where an out of sync operation may provide equal or marginally better performance but the only way to know is to try it with your machine as different mb's and other system components greatly influence the overall effectiveness of such a scenario. I myself have never run into a situation where out of sync operation performs anywhere near as good as an insync one does, this is due particularly to the fact that many of the divisors on current nforce boards simply will not work and will render your machine inoperable without clearing the cmos.

It would be a nice read to check up on Drisler's sticky - http://www.ocforums.com/showthread.php?s=&threadid=257741

In-Sync is better plain and simple.