Freezing mac - Edit impossible

Hi community and happy new year.

I am having major problems editing on my mac and are in desperate need of some tips to try to remedy the situation.

My problem is that whatever I do, every clip move I make, every setting i tweak and every little action summons the colorful ball of the mac - stopping any work session dead in its tracks (or - there is actually no tracks to stop, because I can never get the work session rolling).

This problem has come and gone through the last year, but now it seems to haunt my every session and not let go.

If you want to torture yourself, imagine sitting on a deadline working like this:
https://vimeo.com/497913401/61530755df


Please help me.
J

Techincal specs:
Computer:
- iMac 27" 2019, Catalina v10.15.7
- 3,6 GHz 8-Core i9, 32 GB DDR4, Radeon Pro Vega 48 8GB, 1TB SSD (828 GB free space)

Davinci:
- Version 16.2.7.010 (Studio)
Raw files:
- 4K h.265 .mov files (optimised media in edit)
- stored on a seagate 10TB HDD

You don't mention the most important part: your GPU!
Please also mention your MacOS version.
Did you try to monitor the temperature with a tool like TG Pro?

I have never seen such behaviour with both of my Macs. They are much more stable than our 12 PCs in the lab.

You don't mention the most important part: your GPU!
Please also mention your MacOS version.
Did you try to monitor the temperature with a tool like TG Pro?

I have never seen such behaviour with both of my Macs. They are much more stable than our 12 PCs in the lab.

Thanks, I have now updated the tech specs. I have not monitored the temp, but the fans are running at a stable low noise speed.

Is Live Save enabled? Does it improve if you disable it? It's not normal behaviour if it's enabled, but it does perform a save on each action. If the database is on a remote server on a high latency network it can behave like in your video.

You mention optimized media, which format? Is the 10TB hard drive fast enough for real time playback of that format/codec? If not all media is optimized, 4K H.265 can slow down performance particularly if it is long GOP and you have made edits (Resolve has to decompress frames up to the point of a key frame) or if it's of a variant that isn't hardware accelerated by your CPU or GPU.

Can you post a short clip to test?