i have 2 Gb 800mhz Kingston ram and 1 Gb Samsung 667 Mhz , i have Asus p5-n73 cm board , some1 said to me that they both cannot work together , but its working fine , and Windows 7 rated 5.5(2 gb) to upgrade 6.6 (3 gb)
is it danger for pc? games ???
it's auto by default. BIOS will knows to run the slowest memory. Furthermore, it's works but also took additional performance hit by forcing the overall ram to run in single channel. Stick in another matching 667mhz 1GB Ram will bring it back to dual channel.
MS rating is misleading-score on amount of ram not performance.