Memory for Athlon 64 X2 AM2 CPU

Good afternoon everyone. I need some memory advice. According to the AMD web site, the following memory listed below is compatible with all AM2 processors. I need clarification as to which memory would be best for a 3800+ or 4200+ AM2 processor, as noted below. The Motherboard this processor and memory will be used on is the Asus M2N-E. I am looking for 2GB (1GB x 2) of memory and don't want to drop more than $300 or so on it, give or take a few.

Processor(s) desired:

Athlon XP X2 3800+ AM2 (Retail Boxed)

or

Athlon XP X2 4200+ AM2 (Retail Boxed)


Memory Types Available:

PC2 3200 (DDR2-400)
PC2 4200 (DDR2-533)
PC2 5300 (DDR2-667)
PC2 6400 (DDR2-800)

I would prefer a processor with 1MB x 2, but the models that have that cache size (4000+, 4400+, 4800+, 5200+) are either very hard to find or are quite a bit more expensive. Thanks for the input!


-- MaSoP

Appreciate the input. The actual figures all come out to 400 for all X2 processors when you do the math on a calculator. There are .25 and .50 and .75 figures to deal with for some or the speeds. It appears that you are rounding the multiplier. If I get a 3800 model with PC2 3200 memory (2GB) and then 10 months from now, I want to upgrade to a 5000 or above, would that require I replace the memory with PC2 4200 or above? I keep seeing system configurations with PC2 4200 and PC2 6400 and other memory speeds with various X2 models. I assume they are OC'ing? I have no need to OC. I just don't want to get memory for a slower processor that isn't useable on a faster model in the future. That sounds like a very pricey upgrade path being forced by AMD. Thanks!

-- MaSoP