Slow caching

I've edited and graded a 3' film that was shot in rather low light in 4k and I've had to apply a tonne of noise reduction to it. I can't watch it without dropping frames. I'd be fine with this if it cached faster but it seems to take about an hour. And then it loses its caches when I come back to it after shutting down.

If I render on the deliver tab it takes less than ten minutes to render the entire film. I was wondering if it isn't using the GPU for caching.

Previously I've just used Resolve for grading and I've managed with the powerful playback and with caching the odd shot that needs it but this particular project is a kind of favour and for a friend and isn't going to be finished for a while. It's driving me a bit crazy.

Many thanks for your help.

John

Losing the Cache between sessions isn't normal.

Make sure you're using only internal drives for everything. I recommend a five drive setup as a starting point for good speed and organization.

System
Databases
Export
Cache/Gallery/Optimized Media/Proxies
Media

Make sure the Cache drive is the first one listed under Preferences>System>Media Storage.

Thanks for the reply Jim.

My projects are on the system drive but I've got the media and the cache on the same internal drive, that is in fact a striped pair.

The project is certainly acting strange. I recently moved the project onto a new, fast PC with 128Gb of Ram and I'm getting render errors and errors on file output as well. I just changed the storage location and it seemed to have improved the caching but it still wasn't playing through some WIP pan transitions. Now it's crashed.

I'll try some more experiments tomorrow.

John

"Use render cached images" is off by default, so I assume you're not rendering from the cache. In that case, if caching is slower than rendering it could indicate that you're caching to a very high bit rate format and the disk can't keep up. Project Settings > Master Settings tab > Optimized Media and Render Cache section > Render cache format

A striped pair suggests two spinning hard drives, that might be too slow. Especially since everything is on the same logical drive. What is the timeline resolution?

Thanks Roger.

The project now seems to be behaving much better. Restarted and my renders are still there.

I think it must have been a problem with old settings being present in the project after bringing it over from the old computer. I've reset all the media locations.

Also, I didn't have automatically cache transitions in user mode checked on. I've never needed it before now but I'm using soft-edged WIP pans that couldn't play in real time.

My media drive is a mechanical striped pair but has a speed of 400MB/s. Only way to get both the speed and amount of terabytes that I need.

Fingers crossed it's problem solved.

John