Puzzling system delays  

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Every couple of days my 2015 MacBook Pro running Mojave 10.14.4 goes into a state where it simply pauses for 2-3 seconds. I can be typing and nothing comes out, but then in a couple of seconds everything I typed spits out on screen. I can drag a window and nothing happens, and suddenly the window jumps where I moved it.

A reboot fixes the problem temporarily and it comes back in a day or two.

I tried quitting every open program one by one, then every menubar app. Then I turned off Bluetooth.  Then I turned off WiFi.  Problem persisted.

According to iStat Menus, there's no system load at all and no network traffic (in KB/s).

I reset the SMC and NVRAM for grins and giggles. The problem returned.

Right now it's only pausing maybe every 5 minutes.  Sometimes the pauses are every 30 seconds.

Any idea what this could be and how to diagnose?

Dear Allison, has the issue been resolved? If not, could you please run EtreCheck, generate a report and paste it here so that we can dig deeper. I am sure the report may even directly help you solve this, if it hasn't been solved already.

16 Answers

Ok, I can confirm that my delays are not caused by CMMX, and related to that I can confirm that CMMX causes me no delays when it's installed. So that particular red herring has been tossed back.

My current issues are keychain related. Mail and Safari are most affected. I have some specific scenarios where these do and don't manifest, but what I want to do is wipe out my keychains and start fresh. Except, you know, for the part about where I definitely do not want to do that.

I wish Keychain First Aid still existed, if only so I could rule that out as my magic fix. Because ... I'll never know.

This post was modified 5 months ago 2 times by Dave Hamilton

I did try this "delete the alphabet-soup folder and restart" solution and, while it makes me feel better knowing that many, many of these indexes have been rebuilt, my delays still exist.

Edit: this might well have fixed my "delays when Safari is prepping its list of passwords to show me" problem. I need more time to test, but... it's faster than it's ever been. My Mail keychain lags still exist, at least for now.

Should become a mantra - if you think you need a macOS utility, check to see if Howard at Eclectic Light has already written it. See if this helps:


Hey @AlexSantos - sorry I never got back to you on your idea of running EtreCheck.

But I MAY have found the culprit.  To sum up the situation:

Every few weeks, my Mac hangs intermittently every 20 seconds or less.  The only way I've fixed it has been to reboot the Mac. I eliminated all running apps including all menubar apps and shut off the network.

It was suggested that I eliminate everything connected via my CalDigit TS3+ dock but it was so intermittent I couldn't catch it in the act.

Today I was able to remove things from the dock one by one and keep track of the intermittency.  I unplugged everything until it was Ethernet to the dock, my LG 5K monitor to the dock via TB3 and my Mac to the dock via TB3.  Still happening.

I unplugged the monitor from the dock, and it took a really long time for my MBP to regain the screen, but it eventually worked and there was no lag.  It seemed to be the monitor.  But as I was bemoaning that the MOST expensive not-under-warranty and irreplaceable component was the cause, @StevenGoetz aka @Goatman suggested it might be the cable!

I was using a convenient 40" long TB3 cable that came with a Belkin dock. I replaced it with the stupid short TB3 cable that came with the CalDigit TS3+, plugged in the monitor to the dock and BOOM, the Mac screen came right up.  And the lag appears to be gone!

Too soon to do a full victory lap but I'm doing a small victory jig because it feels like it might be finally solved!

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