>>didnt know you could let cas3 memory overclock to cas2<<
some bioses allow this yes
>>What would be the benefits and is there a risk involved in doing this?<<
less latency .. better performance in memory intensive apps.
>>I mean could the memery or mobo be damaged by doing this or will my system just freeze also in my bios there are two cas settings should i change both or just one ?<<
Not likely you will damage the mobo. Possible you could damage the memory.. still not likely. If the memory can't handle the timing, it will cause system instability.. from alot to a little depending. If you change both, it will be more aggressive than if you change one.
***Hey I run Intel... but let's get real***