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2213 Views 3 Replies Latest reply: Jun 17, 2010 11:17 AM by JaimieV
Inactive RAM usage is not a problem; it is a normal & beneficial consequence of the advanced memory management system of OS X.
Inactive memory contains items that may be used again soon & are thus temporarily retained in memory to avoid the extra time it takes to fetch them from the hard drive all over again. If these items were released from inactive memory prematurely, the performance of your iMac would suffer. To avoid this, the memory management system constantly monitors what is in inactive memory & tries to release parts of it to the free memory pool only a when it becomes obvious its contents will not be reused again soon, for instance when you quit a process. However, since inactive memory contains items shared by several processes, quitting one process does not generally release all its inactive memory.
Another way to look at this is free memory is memory unused by any process, active or inactive, & thus there is no benefit to having large amounts of it doing nothing.2008 iMacs: 24"/3.06 GHz + 20"/2.66 GHz; White MacBook/2.4 GHz, Mac OS X (10.6.3), Kensington Trackball; Airport Extreme 802.11n; assorted iPods and older Macs
Great explanation of Inactive memory. But lately my MacPro (dual quad 3ghz with 8 gb of RAM) has been slowing up. When I check the RAM amount on one of my widgets, the Inactive memory is 6-7 GB and the amount free is like 64 megs.
The programs I have open are InDesign, maybe photoshop and two or three pages in Safari. Could something not be releasing my Inactive memory?
MarkMac Pro Dual Quad 3GHz, Mac OS X (10.6.3), 8 GB RAM
As RC-R says, inactive ram will be released on demand. Think of it as "recently used things" cache, because that's really what it is. It's working as designed.
It may be easier if you think of your available memory as the sum of free+inactive. iStat has this as the default view, for example.iMac i5 2009; MBP 13" late '09; Air '07; Mini '09; Mini '08, iPhone 3Gs, 2G, Mac OS X (10.6.4)