MacBook Pro M4 really struggling with Node render

Ok, ive not been using Resolve for long, so im going to assume this is user error, but I cant see where im going wrong.
Im on a M4 pro MBP with 24GB, using the final release of DR20. Mac Os15.5

I have a 3.5min long 4k canon clog3 clip, and I keep trying to use the noise reduction on my second node, after a CST. Ive turned on Node cache and it took about 20-30mins to render the NR. The blue line went across really slowly but it got there. Then I had smooth playback. I can adjust nodes further down the chain without any issues. I saved the project a few days ago and have just gone back to it. The best I can get is about 12fps playback at half resolution. Full resolution (1080p timeline) drops to 1-3fps. This is totally unusable. The thing I cant figure out is why. The node cache is on, and the cache manager is showing a big file, so it's still cached, only it's not. Render cache is switched to user, but nothing is getting rendered. The number on the Node is now red again, but it's not re rendering anything.

What am I missing? This isn't the first time ive had to waste yet more time letting this node re render (had to do it about 4 times on the first day, as it kept re rendering. Nothing has been touched in the first node, and no cuts or edits done to the single clip.

Where have you put your cache folder?

It's on an external SSD which never gets disconnected.

Noise Reduction is one of the most demanding effects in Resolve. The M4 Pro's GPU might be struggling with 4K footage + NR.

A couple of things to try:

- Go to Project Settings and check your Render Cache format. Make sure it's set to a high-quality codec like ProRes 422 HQ.

- Try clearing the cache manually (Playback > Delete Render Cache > All) and re-rendering the node.

Sometimes just toggling the NR node off and on again can force it to re-evaluate the cache. Hope that helps

Thanks but its more the fact that i have to keep re rendering that is making mew loose interest in DR.
I understand that NR will slow everything down, thats why im trying to use Node Cache, but if i keep re rendering it then whats the point. It adds 20-30mins to my workflow time. Im happy to do it once, but not so often. It’s not even showing red, so i know notihng has changed before it.

Id say 1 in every 3 times i open this Project i see that the Node has cached, but it’s stuttering. It’s still blue, there is no redline above the timeline. I could of course turn the node off for now, i thought Node caching was designed to stop needing to do this.

Version 20.0000049

Opening my project force closes it every time on launch.
I was using magic masking
Polygon tools
And compound clips trying to achieve desired fx in fusion page which. After hours and days of self teaching.

Now I can not open that project but I can open others.

I am using an iPad Pro 2024 M4 With Magic Keyboard and bought it specifically for DaVinci resolve, I was prompted with an upgrade option so I upgraded to 20.00000.49

Please help as I am missing deadlines and this is my current work flow which is being hindered by this issue.