What if low speed ram coupled with high speed one

[Rohit_49]

My aunt has an old laptop in which i have to upgrade the rom. The problem im facing is todays ram moduleds are clocked @1333mhz or so(ddr3). But the ram in laptop is clocked @700mhz or something. So can i add an couple a high speed ram with a low speed on???? Will it work in dual channel or i have to change old ram????
Also is worth to upgrade ram to 4gb and will it increase day to day performance such as multitasking n smoother web surfing. Gaming is not taken into consideration.
Specs : intel i3 2330m 2.2ghz
2gb 700mhz ram
Nvidia 410m graphics.

 

[popatim]

My recommendation would be to NOT mix ram. Order a matched full set/kit of however much you need. These will be tested to work together. Also make sure they are compatible with the laptop. I like Crucial.com for times like these. Often you can find the memory they recommend for a decent savings elsewhere on the net.