Memory upgrade for 640m/1405

I recently purchased a 640m with the following configuration:

T5600 @ 1.83
1 x 1024GB PC2-4300 at 533

CPU-Z tells me that the installed memory is "Mosel"... I've never heard of it personally. Just curious on peoples thoughts on whether I can just pick up another 1024 chip of a different manufacturer. I know I'd be better with an identical stick, but I don't have the cash to swap out the existing one.

Also PC2-4200 seems to be more abundant... what's the difference between PC2-4200 and PC2-4300?

Thanks in advance!

 

Go here to read.... http://www.crucial.com/store/listparts.aspx?model=Inspiron+640m


and here to buy.... http://www.newegg.com/Product/ProductList.asp?Category=17&N=2010170381+1052910525+1309121113+1309221133&Submit=ENE&SubCategory=381

There is no pc 4300 just 4200 @ 533 mhz and 5300 @ 667mhz
For dual channel to work correctly, both sticks must be the same/same

The t5600 cd2 runs @ 667 fsb but dell sells ram that runs @ 533 PC 4200. In the old days...LOL one would want to run RAM that matches the FSB of the processor, like P4's. However from what I have read it does not seem to matter performace wise with the CD2/CD. The MOBO/chipset on the 640m/e1405 will run 533 or 667. My 640 shipped with 2gigs pc4200 @533mhz the CD2 I ordered is the t5200 with runs 533 mhz FSB.

Mosel... http://www.mvc.com/

 

Yes, newegg.com is a good place to go to buy some RAM, as joes has linked. Bear in mind, that dual channel does very little for performance. There may be a little increase in memory intensive programs, but overall it is not worth the extra time and sometimes money it costs.

 

the modules do not have to be the same with the intel 945 chipset(thats what you have in the 640M), you can get dual channel with 1.5gb, if you mix 533 and 667,you will get an overall 533, but the capacity doesnt matter anymore, which is a plus since most laptops ship with 2x512, so one 512 533 stick and one 1024 667 stick will net you 1.5 gig @ 533 dual channel