I see some laptops are supplied with one 2GB DIMM and one 1GB DIMM to give 3GB total. Does anyone know if this performs as well as two 2GB DIMMs where only 3GB is available due to using a 32-bit OS? On a desktop PC 'd expect two equal-sized DIMMs to work better as they'd be in dual-channel mode but I don't know if this is true for laptops.