Satellite A105-S101 Memory upgrade help

I purchased a Toshiba Satellite A105-S101 notebook with 256 MB.
I would like to upgrade to at least 512 MB. I haven't opened
the memory cover yet but I think it has one 256 MB SDRAM.
According to the docs the memory type is :
PC2-4200 DDR2 SDRAM

CircuitCity has a good deal on a Kingston Technologies 512MB PC2-4200 DDR2 SDRAM but I'm not sure this is the best upgrade because it would not work with my existing 256MB
in dual channel mode.
According to the Toshiba Docs I would get better performance if I install a matching 256 MB SDRAM :
Memory
• Configured with 256MB DDR2 SDRAM (both memory slots may be
occupied)
• 256MB(min)/2048MB (max), 2 memory slots using 512MB PC4200
DDR2 533MHz SDRAM, dual-channel support requires two
memory modules of same capacity and clockspeed

Would the dual channel performance be noticable ?
Any advice on what to buy for this ?

Thanks.

 

Dual-channel will only help if you're running intense 3D programs like Maya. You'll also have to get the full 2GB to really see any improvements in games. What are you going to be doing with your notebook?

 

I'm planning to use this notebook mainly for work related
applications, MS Office , etc. However I would like to play
midrange games occasionally. I'm not looking to play Doom3
or HL2 on here, I have a desktop system for that.

I'm tempted to buy the 512 MB from CircuitCity for a total of 768 MB.
CircuitCity has this :
Kingston Technologies 512MB PC2-4200 DDR2 SDRAM Notebook Memory $34.99 after rebate

 

You don't really need the dual-channel RAM then. Just go for the extra stick of 512MB - that should suit you well.