Photoshop est devenu extrêmement lent

Unfortunately you haven't given us any information about your system. Therefore, all proposed solutions are a look into the crystal ball

What has been changed on your system before the issue occure?

What do you’ve done exactly to try to solve the problem.

Please provide a copy of your 'System Info'. This can be get from the Photoshop menu item Help > System Info. There's a copy button in the System Info dialog. Press this button and paste the info into a text file and attach it to your next forum post.

In most of this cases there are a incompatibility or an issue with the graphic card and/or the appropriate device driver. If you have installed a NVidia card make sure that you’ve install the latest Studio version of the graphic driver.

If you’ve buildin a CPU with an internal GPU try to deactive this internal GPU. This internal GPU can causes some issues.

Check GPU compatibility in Photoshop | Photoshop

Resolve GPU and graphics driver issues in Photoshop | Photoshop