Hi guys.. Need help from u guys.. I hv read sumwhere telling that if your mobo only support DDR2 533mhz, u can still use DDR2 667mhz coz the mobo will automaticly downclock your ram to 533mhz.. izzit true?

coz currently i'm using 512mhz ram on my laptop and i wanted to upgrade my laptop ram to 2gb dual-channel (1gb x 2).. but the thing is 1gb ddr2 667 is much more cheaper and easier to find than the 533mhz.. and my laptop only support ddr2 533mhz (read it at intel website <-- dunno true or not)..

so back to question.. can i use the ddr2 667mhz instead of the 533mhz? if 667mhz can be use instead of 533mhz do they have any impact (performance/future defect/problems)? and do 1gb ddr2 667mhz X 2 (2gb dual-channel) with give a same effect as 1gb ddr2 533mhz X 2 (2gb dual channel) on the mobo that support only ddr2 533mhz?

here's my laptop model:

Acer Travelmate 4021NWLMi
Intel Pentium M proc 725 (1.6ghz, 400Mhz FSB, 2MB L2 cache)
Intel 915GM Express chipset

btw izzit relevent if upgrade my laptop to 2gb ram based on my laptop spec ? or i should just use 1gb ram (512 x 2) instead?

hope u guys can help explain it to me.. anyway thanx in advance..