Snow Leopard uses more RAM?

Question

I just installed Snow Leopard on my MacBook Pro and found that RAM usage is obviously a lot more than 10.5 when my system is not running any demanding programs at all. With only Mail, Safari and iTunes running, RAM usage is already more than half of my 3GB RAM, which is the maximum for my 2.33Ghz MacBook Pro. I've heard some people say that to use 10.6, you need at least 4GB RAM to make your system really meaningfully workable. Is that true? Is it really true that 10.6 itself uses more RAM than 10.5?

Answer 1

If you've got the ram, SL will use it. It's supposed to be that way. Reading files from a hard drive really can't keep the OS running as fast as the other hardware can provide. New program features don't work as well with limited ram.
I think that every new OS uses more ram than it's predecessor (same for Windows). Snow Leopard may take less hard drive space, but part of that is because code for PPC Macs has been removed.
Every time a program has to use a hard drive to store part of it's code it's running too slow. I look forward to new memory management techniques that will allow for immediate use of the computer, but still continue to load itself into all the ram it can use. Some of this is already happening, but it will get even better.
As the CPU's get faster, and the memory management systems become more powerful I expect to be able to use even more ram in the future. My 3 year old MBP also has a 3GB limit, but my iMac supports 8 GB of much faster ram. I don't expect to be doing the same type of work with my laptop which shipped with Tiger as I do with the iMac and will probably sell the older laptop in another year to offset part of the cost of the next killer MBP.
Typically I need the MBP to run Windows at a clients site, and XP with 1GB assigned in Parallels has been good enough. Soon I'll need to run Windows 7 on a regular basis, and it requires 3 or 4 times as much ram as XP to get the best performance, plus the IC2D processor can use an update with a couple more cores
Ram is still the cheapest way to help a computer perform at it's best, so when I can, I add all the ram a machine can use and expect changes in the OS and programs to eventually 'obsolete' my machines every 3 to 5 years. I say obsolete because I tend to voluntarily upgrade to the latest hardware and programs when the prices taper off a little.
We are only seeing the beginning of what Snow Leopard can do. The more powerful programs aren't really ready for SL's performance enhancements yet, but as they come online in the next year or so I think they'll take advantage of even more ram...
Meanwhile, there aren't any programs that really require SL and there are still a few that won't work well or at all. Leopard worked very well on my laptop.