I recently noticed something I did not know..
These AM2 models:
4200, 4400, 5000+ are NOT very well if you have DDR2 800Mhz or any other round number of MHz, Why? I'll show you why:
"Here is how the frequency of a CPU and the memory is figured on AMD platforms:
reference clock x multiplier = processor/memory controller speed / divisor = memory DIMM speed
First off, the reference clock is always 200MHz. Raising this number overclocks the entire motherboard and therefore not only voids your AMD warranty, it also will cause instability depending on which component on the motherboard stops functioning first because of the overclock. With that said here's an example:
200MHz (reference clock) x 14 (set by FX-62 CPU) = 2800MHz (CPU and memory controller speed) / 7 = DDR2-PC6400 running @ 400MHz
X2 4800+ Example:
200MHz (reference clock) x 12 (set by X2 4800+CPU) = 2400MHz (CPU and memory controller speed) / 6 = DDR2-PC6400 running @ 400MHz
Because whole-step multipliers and divisors (as opposed to half-steps like "6.5") are used you'll notice that AMD64 processors run at frequencies that are multiples of 200. You will also note something about the speed at which memory is run. Because DDR2 runs at 400MHz, every other frequency speed isn't evenly divisible by 400. For instance, here is what you get with X2 5000+:
X2 5000+ Example:
200MHz (reference clock) x 13 (set by X2 5000+ CPU) = 2600MHz (CPU and memory controller speed) / 7 = DDR2-PC6400 running @ 371MHz "
Meaning it will downclock your memory by default and might be limited in overclocking.
[Its a little old but I just noticed it..]