Question about WD Red Plus

This is a storage system, not a workstation!
If I were you, I would get a professional system, at least a + system with a fast processor...

Hello, unfortunately the DS118 does not support SSD cache. There is the expensive possibility of replacing the WD with an SSD of a similar size or you can use a programme such as ACDSee, where you can generate a preview of the folder and it saves the thumbnails the next time you look at the folder, so that the preview is immediately available the next time you look at the folder. Unfortunately, more RAM in the Synology doesn't help either, as this can only be used for apps or VMs.