How do you know if more memory will help?

[NeilF]

If you have say 512mb of ram, how can you tell if your machine is actually using more than that (generally)?

In 'Task Manager', if you look at 'Physical Memory', is the 'Total' showing you this? ie: If it's less than 512mb, then basically you have more memory (at that moment) than the computer needs?

 

[NeilF]

Id think with 512mb of ram, if you increased it to just 1Gig, you'd notice a difference in XP regardless of what you do on the PC. For games and stuff, going up to 2gig you would notice an improvement.

What is being done on said PC?

The machine in question is just a server - Torrents, printing, email, word etc...

But I'm more just interested in the concept TBH.

If the machine says it's 'Total' memory usage is under 512mb, then that means (surely?) the 512mb stick I have in the machine still isn't being fully used? (At that moment)

 

[NeilF]

Your machine will never fully use 100% of that 512Mb stick. Windows will page memory to disk before that happens.

Windows is very conservative in that it always likes to have quite a bit of free RAM at all times. So even if you halved the memory to 256Mb and ran the machine the same way it is run currently, windows would still never use 256Mb. Your machine would run a lot slower as windows will use virtual memory (your hard drive) before it ever fills the 256Mb.

Therefore even though it appears that you are not using the full 512Mb, you may actually be using more!

If you really want to know a bit more, and want to monitor more than your memory usage, here is a good place to start.

http://technet.microsoft.com/en-us/sysinternals/default.aspx

Ahhh!

So on this machine at the moment for example:-
PHYSICAL MEMORY
Total: 523760
Available: 44568
System Cache: 125036

KERNAL MEMORY
Total: 88008
Paged: 75192
Nonpaged: 12816

What's that actually saying? Nearly all the memory stick is full, but how much is being used in total (memory and disk)?