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ls1dreams

macrumors 6502a
Original poster
Aug 13, 2009
629
236
Hi,

I have a macbook running OSX 10.6.8 (sorry, I know this is 10.8 forum but there isn't a .6.x one). Felt more appropriate to post it here than mavericks since mavs uses compressed memory.

Anyway, I'm finding it very common that when my free memory runs out, my system comes to an absolute crawl, as it would when an OS starts disk paging.

I'm running 8gb, and a typical example might look like this: (descriptions from apple)

Wired: 1.3gb - "Information in RAM that can't be moved to the Mac's drive. The amount of Wired memory depends on the applications you are using."

Active: 4.5gb - obvious, active memory

Inactive: 1.85gb - "Inactive memory is available for use by another application, just like Free memory."

Free: 300mb - "This is the amount of RAM that's not being used."

As soon as free dips close 0, everything gets insanely slow. I was under the impression that when this happens, the inactive memory should be flushed and filled with the new data, which shouldn't have a performance impact, but that's not what I'm seeing.

Any ideas why this might be happening?

Here's a quick test I did with the numbers above: I kept opening multiple tabs until free memory dropped near 0. Before then, according to activity monitor, my page outs # was 1.5gb. After opening a few more tabs at a CRAWLING pace, I took a look and the free memory remained about the same, but page outs had increased to 1.7gb.

So, despite having nearly 2gb of "inactive" memory, OSX is paging to disk. Is this the normal behavior? Why would OSX sacrifice immediate performance for the chance that I -might- revert to one of the apps I was running previously?
 
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