Inac ten tvoj notebook vie podla Aceru max. 2GB http://support.acer.com/acerpanam/notebook/0000/Ac er/TravelMate2490/TravelMate2490sp2.shtml
Chipset mozno nevie adresovat viac. Mal si dokupit len 1GB presne stejnu jak si tam mal doteraz, nech ide aj dualchannel.