Now, That's Smooth: Monitoring Your Memory

By David@smalldog.com

Mac OS X uses what’s termed a “virtual memory system” (VM system) which essentially refers to the amount of memory an application thinks it needs to run, and is therefore allocated. Usually only a small portion of that memory is stored on the physical RAM chips. When (and if) your memory is insufficient in the face of running applications and data processing, the OS will seek out inactive memory and swap the file into a…(ahem)…”swap file” stored on your hard drive to make room for active memory. These files are sent out in units called “pages,” and this specific action is termed a “pageout.” The process of swapping, if too frequent, can slow your computer down and cause your experience to be decidedly un-smooth.

One way to check up on your RAM and VM swapping is to open up Terminal and simply type the word “top.” What you will see is a dialogue that looks like this:

What you want to pay attention to is the ratio of “pageins” to “pageouts” (boxed and pointed to in the above figure). If number of “pageouts” is non-zero and growing rapidly, and is near or higher than the “pageins,” it’s time to take action. First, restart your computer. Then, run Terminal and the top command. Last, work as you normally do and monitor how quickly things change…it may be time to invest in some more memory.

By David@smalldog.com