KB: Slowness at startup

Created: March 25, 2021 | Updated: August 21, 2023

Here are some things that can cause a slow startup.

Starting in Version: 18.0
Up to Version: Current

Solution Details

Your  slowness to start could be as a result of having too many previous documents loading at startup. A quick easy thing to try is to Hold the CTRL key down when starting Altium Designer and keep it held down until the program is fully loaded. This will allow Altium to start up without loading last document set.   If this makes a difference, you may want to consider unchecking the box for "Reopen Last Project Group" (version 18 has "...Workspace") under  Preferences ► System ► General ► Startup section. Along with this, you should probably also uncheck the box for "Restore open documents" under Preferences ► System ► View ► Desktop section.  These two setting changes may speed up your shutdown as well.
Long delays when opening a project in Altium Designer can be related to unresponsive printer drivers. The first time a project is opened or saved Altium Designer polls all printers that are installed in the Windows Control Panel, if a response is not received from a printer, there can be lengthy timeout.  This issue usually only shows up for the first time of a new session and things work fine after that.  Uninstalling all printers can help to resolve the delay opening projects.  Reinstalling the printers one at a time and checking that projects open between each printer install can help to determine which printer is causing the delay.  Then you can try updating the print driver for that printer or leave it uninstalled.

If the installation of Altium Designer was performed with an offline installer, try changing the  preference setting here:

Preferences ► System ► Installation >  push the radio button for Global installation service.  After an offline install, the radio button is pushed for Offline installation, but if the location is not available, it will not succeed at checking for updates.  Alternately, for testing, you could try going to Preferences ► System ► Network Activity > uncheck the box for "Altium Portal"
When you go to File ► Open Project, Altium Designer also queries your managed server (if you have one) so it can present those projects as well.  If you have a managed server or workspace try logging out of it first.  If your project files are on a server or in a folder that maintains a network or cloud copy such as OneDrive or Dropbox this might also be the cause.  Try copying them to a different local drive to test.

Try launching Altium with "Run as administrator".  In one case this cleared an issue causing a 90 second delay when trying to open projects for a customer that was using SVN.

Large user setting files (*.tlt, *.RCS, *.RAF) can cause slow startup and shut down.  You can delete these files manually from 
 C:\Users\UserName\AppData\Roaming\Altium\Altium Designer {GUID}\ or by removing preferences.  Here's a Knowledge Base Article on removing preferences:
How do I reset the Altium Designer configuration to the installation defaults?

Slowness can also be interpreted as long delays.  Please see this Knowledge Base article on Freezing or Long Delays:
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