Suddenly Davinci has begun to lag

Don't know why yesterday my project went fantastically well ( I use an ext SSD) whereas today inasptectedly it has begun to lag all the time.... I made almost nothing different from yesterday... What can it be?

I always advise working exclusively from internal drives.

USB-c or Tbolt3 external SSD's are fine. I suggest you look at your cache folder to see if it's full.

I'm sorry, Jim, but that recommendation is pretty dogmatic.
While the database should be internal or an a permanently connected device, you can work just fine with external storage for media and even cache, depending on throughout and access times.
I can work very well with the cache and/or proxies on an external SSD-RAID, for example.

I can work very well with the cache and/or proxies on an external SSD-RAID, for example.

Until it gets disconnected, intentionally or otherwise. Which doesn't happen with internal drives, hence...the recommendation.

And it's just that, a recommendation. It's not life or death. Just an idea that avoids potential issues.