All Posts by Date or last 15, 30, 90 or 180 days.
also by Lloyd: diglloyd.com photography and WindInMyFace.com
Thank you for purchasing through links and ads on this site.
OWC / MacSales.com...
diglloyd Deal Finder...
Buy other stuff at Amazon.com...
Handpicked deals...
$1299 $999
SAVE $300

$3899 $3499
SAVE $400

$1498 $1198
SAVE $300

$2299 $1599
SAVE $700

$1598 $1598
SAVE $0

$5500 $5000
SAVE $500

$2600 $2100
SAVE $500

$2798 $2798
SAVE $0

$1299 $950
SAVE $349

$1999 $1399
SAVE $600

$1299 $1124
SAVE $175

$2299 $1799
SAVE $500

$1299 $999
SAVE $300

$3397 $2697
SAVE $700

$3297 $2797
SAVE $500

$1999 $1199
SAVE $800

$3399 $2199
SAVE $1200

$400 $300
SAVE $100

Upgrade the memory of your 2019 iMac up to 128GB

How to get a Better Idea of Memory Usage: Purge the OS X File System Buffer Cache

It can be confusing to evaluate available memory, because OS X can use many gigabytes for the file system cache. Thus, it can be useful to purge the OS X file system buffer cache for that reason, and another:

  • Before performing or repeating a performance test, for consistent results.
  • To assess system memory usage without a bloated disk cache.

In Terminal, use sudo purge:

diglloydMP:MPG lloyd$ sudo purge

Use of 'sudo purge' is harmless; it simply empties file system caches. The 'man' page states:

Purge can be used to approximate initial boot conditions with a cold disk buffer cache for performance analysis. It does not affect anonymous memory that has been allocated through malloc, vm_allocate, etc.

The results can be seen in Activity Monitor under memory usage. The cache will not go to zero because the system keeps some important file system structures cached.

15.6GB of cache used before sudo purge, 1.09GB after (toggle to compare).

Cached files before and after
View all handpicked deals...

Dracast LED500 Plus Series Daylight LED Light
$600 $600
SAVE $0

diglloyd.com | Terms of Use | PRIVACY POLICY
Contact | About Lloyd Chambers | Consulting | Photo Tours
Mailing Lists | RSS Feeds | Twitter
Copyright © 2019 diglloyd Inc, all rights reserved.
Display info: __RETINA_INFO_STATUS__