Render cache connections lost

At least one of my projects doesn’t find/connect the render cache of the clips. When opening the project, all the clip’s render status show red (needs to be rendered). And it takes about one hour to render the clips again, so, after rendering, the render status changes to blue (already rendered). If I close the project (after saving it) and reopen it, all the clips show red render status, and the render process starts all over again. This is very annoying because I have to wait for one hour to start to work each time I reopen the project (as the rendering slows down both Resolve and the computer).

Some of the clips need to render fusion output, some color output, some OFX output, and some any combination of these. The render cache is set to “user”, and the render folder is set in the project prefs (the default address). I tried to reconfigure the cache address, but that didn’t make any difference.

The render files are there, all those tens of gigabytes. Resolve just cannot connect them to the clips on the timeline/project when reopening the project.

Now, in some of my projects the render cache is remembered connected properly, so if I reopen the project, the render files are found immediately and render status shows blue in the timeline. But this one project that I’m working on at the moment is driving me crazy!

Please help, any ideas are appreciated!

Thanks in advance.

DR Studio 16.2.7/16.2.8; MacBookPro 15” 2018; OSX10.14.6; 2,6 GHz Intel Core i7; 32GB RAM; Radeon Pro Vega 20 4 GB

Really? No one? Maybe the BlackMagic wizards could have an advice, please!

You can't do this job on a Laptop.

Build an Intel/nVidia desktop with a minimum of five internal drives arranged as follows.

System
Databases
Gallery, Cache, Optimized Media, Proxies (17 and forward)
Media
Exports

Thank you Jim for your reply.

I can't really take this as a serious answer for couple of reasons.

First, I have plenty of projects and even more complicated projects that this issue does not occur, the render files are properly connected – even on my laptop.

Second, you say "you can't do THIS job on a laptop". Meaning what? It does not say on the specs that you cannot work with Resolve studio on a Mac laptop. Plus, the project that I'm referring to isn't anything enormous or very complicated, so it's hard to imagine this project would really be a culprit per se.

The configuration you give, I'm sure, must work well. However, I don't see this as a minimum requirement (or either even a recommendation) in the specs.

I believe that using resolve in a dream configuration makes things flow. Sure. However, I can't believe I couldn't get the render files connected on a laptop.

Any other advice?

I'm still in need for a solution!

I noticed that the problem is connected to copying clips from a project to another, especially if there's something more complicated – a fusion comp or compound clip or...

Copying clips from projects to others seems to be a "legal" thing to do, so I suppose there has to be a solution for this render cache connection problem too!?

Any advice, especially from the BM engineers?

Can’t help you with a meaningful answer, but losing cache is at best loosely connected to underlying system specs, about as much as calibrating your monitor. And you are unlikely to get any response from BMD team if you don’t get a hard crash.

Caching has changed significantly with v17; how well that's going, I don't know. But pre-17, it's never been altogether satisfactory -- as you report. There is a reconnect to cache files feature added a version or two ago, to deal with orphaned cache files. Did you try it?

It sounds like there's some residual cache confusion, when you copy and paste clips from one cached project to another. But how get around that, without voiding the cache in one or the other?

If there's a solution to this one, it's not obvious. 17 is still beta but is there any way you can contrive to try it?

Thank you, John and Hendrik, for your replies!

Good to know that this is a known issue, and let's hope it will be solved In the coming DR17 real version. (In the middle of this project, I'm a bit hesitant to change into a beta version.) I will try the "reconnect to cache files feature".

I don't really mind if the connection to the original render files (in another project) are lost, if I only needed to re-render the cache once in the "new" project. But the inability to keep the re-rendered cache connected (in the current project) is really annoying.

And if you make a change to the clip/fusion comp/compound clip, then you would need to re-render it. And those render cache files are always disconnected when you save/close/re-open the project.

Hope it will be solved soon!

Thanks again!

Cache being lost is a huge ongoing issue for me. The chaps going on about system specs aint got a clue, this is absolutely a software issue. I'm running a 24-core threadripper with separate m2 SSDs for OS, Footage and Resolve cache. The project is in SQL database on NAS with SSDs and 10G ethernet. I am constantly waiting for my Fusion output cache to rerender after Resolve can't find it. It's absolutely garbage with a lot of Fusion clips on the timeline. Almost at the point of being unworkable because of the amount of time I am wasting by having to rerender the same thing all the time.

Other than Jim suggests I use an external SSD RAID for my cache and I’ve never experienced a lost cache if that drive is connected before I start DR.
But I also make sure not to use fancy characters in pathnames and even use underline instead of space (good old UNIX habits). Maybe that helps under Windows too?

I've just discovered that creating a new grade version causes the Fusion output cache to disappear - why?