MBP RAM Upgrade - Free RAM

[zw-gator]

I currently have 2GB of RAM in my MBP and according to iStat I only have 40mb of RAM free.

I've ordered 4GB of RAM and it should be here by next Monday.

Anyway, will I experience any speedups? Does my system slowdown when I'm low on free RAM?

 

[gr8tfly]

You have to include "inactive" memory, too. That's also available for application use - it's just cached incase you relaunch the same app or use the same data.

The main thing you want to look at is the number/size of pageouts. If it's large, relative to the pageins, then more physical RAM can improve performance by reducing how often a page gets swapped to the HD.

This might help:
http://support.apple.com/kb/HT1342

 

[zw-gator]

Take a look (Note: I just closed Excel)

 

[zw-gator]

Here's another (I closed some more apps)

 

[gr8tfly]

Take a look (Note: I just closed Excel)

It doesn't look too significant, but if those pageouts all happened at once, you might notice some slowdown.

You can also use "top" in Terminal - it will show the number/sec. For instance: 88012(0) pageins, 1428(0) pageouts, where the number in parenthesis is events per second. If you have it running, while opening and using your apps, you might see if it's a few or many per sec. Again, it's the rate which will determine whether you will notice a performance hit.

edit: Looking at the Activity Monitor data, it doesn't look significant - the ratio of in vs. out is very small. You have a total of 745MB [essentially] free. Of course, since you've close apps, it's not a good snapshot of your usage.

Also, keep in mind the data in iStat or Activity Monitor is cumulative. If you just booted up and got the pageouts all at once, it's more significant than if the system had been up and running for weeks and the pageouts occurred sporadically.