With the way software is being written nowadays, I would strongly recommened you upgrade to 2GB. Your CPU is ancient by today's standards, so the only improvement you will notice is how much smoother apps will run. Still, the upgrade from 512MB to 2GB is a giant leap and worth the money (if a new system is out of the question).
Checkout www.crucial.com and use their memory advisor tool.
Thanks for advise...
Since I lost the Samsung R40 Manual and was not able to find the
info from Samsung site due to Old PRODUCT, I do not know
whether it can take 2 1G modules or not ....
Cruical.com memory configuration program suggests to use 2GB kit (1GBx2), 200-pin SODIMM, DDR2 PC2-5300 667 memory module ...
The momery module in my R40 is 512MB pc2-4300(266MHZ),
can pc2-5300 (667MHZ) module be used in R40(not R40PLUS) memory slot?