upgrade ram need help

[only4speed]

i got a cheap laptop with 512mb ram. i want upgrade to 1G or more. i checked it with cpu-z. it is ddr2 667ram(pc2-5300) made by Samsung but runing at 266MHz instead of 333MHz. it has a 444-11 timing like pc2-4200 instead of 555-13.( i don't know how to load image, sorry )

now here are my problems:
1. what memory i should by ? 667 or 533? will i get the same timing (444-11, not 555-13) just insert any So-dimm ddr2 667(pc2-5300) ram?
2. should i buy another 512mb to get dual channel? (the mobo support dual channel ram according to manufacturer's note. $200 some is out of my budget at this time, so my choice is limited to 512mb or 1Gb)

I will come back to read you guys reply later so thanks in advance. really appreciated your help.

 

[wun911]

I would recomend you buy the exact same module of ram you have in your lappy.

Buying something faster is a waste of money.

Buying something slower will make both modules run slow.

I think if you are unsure take the stick of ram out and bring it along to a PC shop...