To isolate the problem, please uninstall SQL Prompt and test if SSMS is still slow. If so, reinstall SQL Prompt. If the problem persists with the latest version (Help>Check for updates), please try the following steps:
- Disable Code Analysis function (SQL Prompt -> uncheck “Enable Code Analysis”) and test again; if the problem disappears, it suggests that "Code Analysis" is the culprit, so please contact Support.
- Disable the built-in intellisense under Options->Text Editor->Transact-SQL->Intellisense
- Go to SQL Prompt>Options, click on Export to save your settings, and then try a "Restore all defaults".
- Disable the auto-refresh experimental feature (SQL Prompt->Options->Labs->Experimental features).
- If your SSMS version is below 17.3, you can raise the amount of RAM available for SSMS by using the Large Address Aware utility on ssms.exe (see https://www.techpowerup.com/forums/threads/large-address-aware.112556/)
- If the slowness occurs at startup, try disabling Tab History (SQL Prompt->Options->Tabs->History->Enable Tab History).
Note: If it is Object Explorer that is slow, this is more likely caused by SQL Source Control. Please see here for troubleshooting steps.
If the problem persists, enable verbose logging, reproduce the issue, log a ticket with Support and attach the log file for further investigation.