yes korek sila bro, the more memory mas bright siya hehe, joke. more resources the pc can utilize the faster it operates, kai kan on lang sa RAM, hehehe
ur hard disk will be very happy, kai less virtual memory(pahuway sa pagefile haha)= smoother system performance.
hehehehe, ur mobo is DDR1 compliant, hehehe supports DDR1 memory module default DDR266 or (above ,underclock to 266 i think)
i installed a 1 pc PQI 512mb ddr400 on a p4vmm2, it works, but underclock siya. hehehehe
try to check unsa revision imu p4vmm2 sa ecs website then tan awa memory support list. for compatiblity go look for DDR266 for compatibility, pwede rasad ddr400.
also if u want to dual log its requires more processing power, celeron can handle dual log i think, but due to small cache size nd slow fsb, kamang dyud na.
and lastly if u want to squeeze out lil juice sa imu pc, try to disable unwanted background apps.