gnasher729 said:
The "free memory" number in "Activity Monitor" is very much misunderstood. "Free" means: Your Macintosh didn't find anything useful to do with that memory. ... Add "inactive" to the free memory number.
That is a very important distinction and one that I had a chance to follow-up on yesterday between attending Apple Store workshops.
I restarted a MacBook that had 1GB RAM installed. Then I opened iTunes, iPhoto, Safari, Pages, Sherlock, Dictionary and Activity Monitor, plus this computer had five widgets. The memory usage tab in AM indicated that 18MB was free memory, but approximately 550MB was still inactive.
That was followed by another restart. The same apps detailed above were all reopened, but then I added the following ... Grab, iCal, Mail, Excel, Preview, QuickTime Player and Word. Before I looked at the memory use in AM, I connected to the Music Store to begin a download of a 38 minute National Public Radio podcast.
Activity Monitor showed free memory to be 13MB (just about the same as the 18 earlier), and inactive memory was now 285MB. The system responded well and I was not plagued with the beachball. Having all those items open simultaneously is something that the vast majority of users are not going to do.
However, the exercise should reassure prospective buyers that for more typical use from those not reliant upon the most demanding video and photo apps and others running under Rosetta, 1GB RAM will suffice very nicely. If one feels a need for the security blanket that 2GB would provide to ensure a better night's sleep, by all means go for it. The question is whether or not it is truly needed.