i use RAM DDR3 4GB 1600MHZ, MSI 740GM P45

QUestion is..

1- How to O.C the ram untill 1600MHZ? need setting?
2- Can oc over limit then 1600mhz?
3- If i use 1600mhz ram..and just restart the pc. Did ram auto setting to 1600mhz?

Enter bios cell menu and you will see the memory setting.
Just set to 1:4 and you will get 1600mhz.

MSI 740GM P25?
what cpu are you using?

Mobo MSI 740GM P25...
CPU PHENOM II X2 BE 555..

I dont think O.C ram related to CPU.. Did related??

hehe, since you are using a black edition cpu.
then go into bios see whether got DDR 1600 dram divider?

Since you're using 1600mhz ram, it can easily adjusted at the cell menu. I use same ram as yours, and msi mobo, i think the bios is same. At cell menu on top it shows cpu and ram current speed. At first time I installed the ram, the auto speed is 1066. Change it at ram option to 1:4; ram speed 1600mhz. If you restart and set it back to auto it will stack at 1600mhz from my experience.

if this is about AMD overclocking. thread closed

ask here https://forum.lowyat.net/topic/1601279 thanks