Memory Compatibility issues

[aneet86]

Hi,
I have an AMD Athlon X2 3600+ @ 2 ghz with Transient 512 mb ddr2 533mhz ram on an Asus M2NPV-MX motherboard. i have ordered another Transient memory module of 1Gb ddr2 800Mhz but now i am worried whether it will work on my system cause i have my current ram working on 533mhz. So can i downclock the new 1Gb module to work at 533mhz so that i can enjoy 1.5 GB of Ram all working at 533Mhz ?? Or else I have an option to exchange the 1Gb ddr2 800Mhz module and get another 1Gb ddr2 667 Mhz but again i am not sure wheter it will work and secondly 1gb ddr2 533mhz ram is now no longer available in India and i dont want to sell my 512 module working at 533 mhz..Pls reply asap

 

[aneet86]

Also i wanted to ask ideally which Frequency Ram (533/667/800Mhz) will give me maximum performance from my processor. My processor FSB is rated at 200Mhz (200 * 10 = 2Ghz operating Speed).