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camner

macrumors regular
Original poster
Jun 19, 2009
228
15
I need to figure out what is adversely affecting read/write speeds on an external enclosure.

If I boot into Safe Mode, I have no problems. If I "Temporarily prevent items from opening automatically when you log in" by holding the Spacebar down after entering my login password, I have the r/w slowdown problems, just as if I booted normally.

So, something is launching at startup that is NOT disabled by "Temporarily prevent items from opening automatically when you log in."

How can see what Catalina is starting up for me "behind the scenes" that do not show up in the Login Items pane of Users & Groups? I suspect it was something I installed at some point, because I do customize my system a lot. But, if possible, I'd like to avoid the tedious process of rebuilding my system from scratch and testing the external enclosure after every individual item is installed.

Is there a way to see what launch agents and daemons are starting up when I "Temporarily prevent items from opening automatically when you log in" but that do NOT start up when doing a boot into Safe Mode?
 

Taz Mangus

macrumors 604
Mar 10, 2011
7,815
3,504
  • The files in your user account Library/LaunchAgents get executed when you login to your user account.
  • The files in /Library/LaunchAgents and /Libary/LaunchDaemons get executed when you restart the computer before you login to a user account.
  • Third party kexts that might have been run at boot time. To get a list of third party kexts currently loaded and running, open the Terminal app and enter:
Bash:
kextstat | grep -v com.apple

To unload and/or remove those third party kext look at the link below.

 
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camner

macrumors regular
Original poster
Jun 19, 2009
228
15
Thanks for the tips.

Upon further troubleshooting, this is what I’m seeing.

If I create a new user account and login at boot time from the new user account, I don’t see my issue with slower i/o on the external device. If I then switch users to my usual user account (not rebooting, just switching users), I get the slower i/o. If then switch back to the new user account (without a reboot), I still see the slowdown.

So, from this I conclude that there is something that starts up when I login to my usual user account that is causing the problem. BUT, disabling all of the login items in the Users & Groups Login Items pane, or holding down the Shift key at login (which does the same thing?), does NOT resolve the issue. So something is starting up when I login to a particular user that I can’t see.
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
34,171
15,691
California
If it is specific to just your account it is likely an item in that first folder I listed that that is launching something.

Click the Desktop for focus, then hit shift-command-g, then paste ~/Library/LaunchAgents into the popup and return. Now look in that folder for any launch items.

~/Library/LaunchAgents (~ is your users folder)
/Library/LaunchAgents
/Library/LaunchDaemons
/Library/StartupItems
/Library/Extensions
/System/Library/Extensions/
 
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mikzn

macrumors 68040
Sep 2, 2013
3,005
2,290
North Vancouver
I need to figure out what is adversely affecting read/write speeds on an external enclosure.

If I boot into Safe Mode, I have no problems. If I "Temporarily prevent items from opening automatically when you log in" by holding the Spacebar down after entering my login password, I have the r/w slowdown problems, just as if I booted normally.

So, something is launching at startup that is NOT disabled by "Temporarily prevent items from opening automatically when you log in."

How can see what Catalina is starting up for me "behind the scenes" that do not show up in the Login Items pane of Users & Groups? I suspect it was something I installed at some point, because I do customize my system a lot. But, if possible, I'd like to avoid the tedious process of rebuilding my system from scratch and testing the external enclosure after every individual item is installed.

Is there a way to see what launch agents and daemons are starting up when I "Temporarily prevent items from opening automatically when you log in" but that do NOT start up when doing a boot into Safe Mode?

another approach might be to use activity monitor and view what is taking up the most CPU time? If it is a third party app you can kill that process in the activity monitor (note sometimes they can restart so keep an eye out for that)

I have noticed in the past that some up-daters get stuck and consume a lot of CPU time when they hang - perhaps one of the start up items?
 
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Taz Mangus

macrumors 604
Mar 10, 2011
7,815
3,504
Thanks for the tips.

Upon further troubleshooting, this is what I’m seeing.

If I create a new user account and login at boot time from the new user account, I don’t see my issue with slower i/o on the external device. If I then switch users to my usual user account (not rebooting, just switching users), I get the slower i/o. If then switch back to the new user account (without a reboot), I still see the slowdown.

So, from this I conclude that there is something that starts up when I login to my usual user account that is causing the problem. BUT, disabling all of the login items in the Users & Groups Login Items pane, or holding down the Shift key at login (which does the same thing?), does NOT resolve the issue. So something is starting up when I login to a particular user that I can’t see.

Maybe attack this from using the new user account by looking at what you are running in your current user account and add those to the new user account until the issue shows up. What do you have on the menubar might also give you an indication of things you are running in your user account. Also, are there any thing third party in the System Preferences.
 

camner

macrumors regular
Original poster
Jun 19, 2009
228
15
If it is specific to just your account it is likely an item in that first folder I listed that that is launching something.

Click the Desktop for focus, then hit shift-command-g, then paste ~/Library/LaunchAgents into the popup and return. Now look in that folder for any launch items.

~/Library/LaunchAgents (~ is your users folder)
/Library/LaunchAgents
/Library/LaunchDaemons
/Library/StartupItems
/Library/Extensions
/System/Library/Extensions/

There were 4 items in ~/Library/LaunchAgents:
  • com.adobe.GC.invoker-1.0.plist
  • com.amazon.music.plist
  • com.DigiDNA.iMazing2Mac.Mini.plist
  • com.dropbox.DropboxMacUpdate.agent.plist
I moved all 4 out of that folder and onto the Desktop and rebooted into my usual user. The i/o slowdown still was present, so I guess it is some other culprit.
 

bernuli

macrumors 6502a
Oct 10, 2011
710
403
When the problem is happening what is the output of

kextstat | grep -v com.apple

as Taz mentioned above.


Also, when you restart is "Reopen windows when logging back in" checked?
 

camner

macrumors regular
Original poster
Jun 19, 2009
228
15
When the problem is happening what is the output of

kextstat | grep -v com.apple

as Taz mentioned above.


Also, when you restart is "Reopen windows when logging back in" checked?

No, "Reopen windows when logging back int" is NOT checked.

This is the output from kextstat | grep -v com.apple:

Index Refs Address Size Wired Name (Version) UUID <Linked Against>


146 0 0xffffff7f80eb3000 0x5000 0x5000 com.Cycling74.driver.Soundflower (2) 2D779840-7439-31E5-8A66-D786C3F47B75 <88 6 5 3>

That's the only kext. To disable it, is it enough to find out where it's located and move it out of that location?
 

Taz Mangus

macrumors 604
Mar 10, 2011
7,815
3,504
No, "Reopen windows when logging back int" is NOT checked.

This is the output from kextstat | grep -v com.apple:

Index Refs Address Size Wired Name (Version) UUID <Linked Against>


146 0 0xffffff7f80eb3000 0x5000 0x5000 com.Cycling74.driver.Soundflower (2) 2D779840-7439-31E5-8A66-D786C3F47B75 <88 6 5 3>

That's the only kext. To disable it, is it enough to find out where it's located and move it out of that location?

Uninstall it and see if that helps. You can always reinstall again if needed. Restart the computer after uninstalling it.

 

camner

macrumors regular
Original poster
Jun 19, 2009
228
15
Uninstall it and see if that helps. You can always reinstall again if needed. Restart the computer after uninstalling it.

Thanks for the link. I did as indicated at the link, and for good measure, I followed the steps outlined here: https://github.com/mattingalls/Soundflower

Alas, after emptying the trash, and rebooting, the i/o slowdown still happens. ?

Do you have any third party preferences installed in System Preferences?
Yes. I have MenuMeters installed. I will try to remove that and see if makes any difference.

FWIW, here's a screenshot of my menu bar when logging in with the shift key held down to suppress loading of user login items:
1600547592217.png


So, non system ones are: TGPro (44/1201), which controls fan speeds, Adobe Creative Cloud, Show Desktop, and 1Password.
 

DeltaMac

macrumors G5
Jul 30, 2003
13,486
4,413
Delaware
Keep looking. There could be more than one "helper", and pinning down the blame might take a lot of time.
Activity Monitor can help, too.
 

camner

macrumors regular
Original poster
Jun 19, 2009
228
15
Bingo!

The culprit is TG Pro! I deleted the Menumeters pref pane, to no avail. Moving to the right, TG Pro was the next one to try. It doesn't seem even to have any low level stuff. I just quit the app, and i/o speeds went back to normal.

Some of the more curious aspects of this is the following:
  1. It only affects 1 particular external enclosure (OWC Thunderbay 4 Thunderbolt enclosure, JBOD version). It does NOT affect an OWC USB 3.0 Dual Dock or other enclosures I've tested.
  2. It only affects the i/o speeds for HDDs. I've tried a couple of different SSDs, and their i/o speeds are fine when TG Pro is running.
I suppose it's impossible to know why and how something that reads Mac temperature sensors and increases the iMac's internal fan speed when the temps get too high can influence i/o speeds with a particular enclosure.

Thanks to @Taz Mangus and the others who contributed to helping me find a solution.
 

Taz Mangus

macrumors 604
Mar 10, 2011
7,815
3,504
Bingo!

The culprit is TG Pro! I deleted the Menumeters pref pane, to no avail. Moving to the right, TG Pro was the next one to try. It doesn't seem even to have any low level stuff. I just quit the app, and i/o speeds went back to normal.

Some of the more curious aspects of this is the following:
  1. It only affects 1 particular external enclosure (OWC Thunderbay 4 Thunderbolt enclosure, JBOD version). It does NOT affect an OWC USB 3.0 Dual Dock or other enclosures I've tested.
  2. It only affects the i/o speeds for HDDs. I've tried a couple of different SSDs, and their i/o speeds are fine when TG Pro is running.
I suppose it's impossible to know why and how something that reads Mac temperature sensors and increases the iMac's internal fan speed when the temps get too high can influence i/o speeds with a particular enclosure.

Thanks to @Taz Mangus and the others who contributed to helping me find a solution.

Great that you found what was causing the issue. I know how frustrating this can be to solve. Glad I could help point to finding the solution.
 

camner

macrumors regular
Original poster
Jun 19, 2009
228
15
Well, I spoke too soon...after several cycles of disabling/enabling TG Pro and seeing the impact on i/o speeds, I wrote the post above, thinking I'd solved the problem.

It then occurred to me that I had only done half the job of testing. So, I logged in to my new user, installed TG Pro, and to my surprise and dismay, the i/o speeds are fine. So, I suppose I'm looking at an interaction between TG Pro and some other item that causes the issue.

Boy, is this a pain!
 

Taz Mangus

macrumors 604
Mar 10, 2011
7,815
3,504
Now you can happily mark this thread RESOLVED. Never mind. It appears that we both posted at the same time.
 

camner

macrumors regular
Original poster
Jun 19, 2009
228
15
Final followup...

I contacted the developer of TG Pro, and he got back to me immediately and speculated that the issue may be that "the main issue with this is some HD controllers slow down like crazy when they are queried via the SMART interface for any info. Since TG Pro will query it each time it updates the temperatures, for some controllers it's too much."

Fortunately, TG Pro has a checkbox in its preferences that allow one to disable the "Check hard drive temperatures using SMART." After I disabled that, HDD i/o speeds were normal.

This also explains the other phenomena I noticed, which I thought were odd but that with the explanation make perfect sense.

  • Many, if not most, USB interfaces do not support the querying for SMART information (at least not without the installation of some low level stuff onto your system)
  • SSDs (or at least the Samsung EVO 860 I am using) probably have their controllers respond differently that HDD controllers to SMART queries.
Thanks again for the help. Identifying the app responsible + a very responsive developer = a very happy camper!
 
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