Hi ن٢يف,
Thank you for reaching out to Microsoft Community.
By default, TRIM is enabled on Surface Pro 4. You may check on sure device to make sure if trim is enabled by:
Search for Command Prompt and Run as administrator
Type in this command and hit Enter: fsutil behavior query DisableDeleteNotify
If you get a result of 0, that means Trim is enabled and no further actions needed.
If you get a result of 1, that means Trim is disabled.
To enable Trim type this command line and hit Enter: fsutil behavior query DisableDeleteNotify 0
If you want to disable Trim, type this command and hit Enter: fsutil behavior query DisableDeleteNotify 1
I found here a thread that seems to have the same concern as what you have regarding Trim, you may check this thread.
If this answer your question, we highly encourage you to inform our Community by clicking on Yes or marking my post as an answer. This will help other members who may have the same issue as you. Otherwise, don't hesitate to update us so we can further assist you.
Kind Regards,
Marrion Y.