choppy playback of cached EXRs from a NAS

Hi,
I have encountered a problem with choppy playback of cached EXR-Sequences (CGI generated content, 1080p, 16bit float).

If i am working locally, everything is working smooth and fine - my system has no problem playing back the EXRs, regardless if they are located on my 2TB Data SSD or if i am using Resolves user cache functionality to store them on my 256 GB NVMe Cache Drive.

However, if the exact same EXR-Sequence is located on a NAS (connnected via 1GBit Ethernet), i get choppy playback, regardless if i attempt to play them back with or without activated user cache (same thing with smart cache).
I have double checked the cache folder, the cache files (*.dvcc sequence) are generated in the correct location on the correct drive (256 GB NVMe), regardless if the EXR sequences are stored on the NAS or locally. The cache settings are identical in both Scenarios. The result is the same, even on other machines - if the source files are stored on a local drive, playback of the cache is smooth, if they are stored on the Network drive, playback of the cache is as choppy as if no cache was used at all.

When generating optimized media however, playback becomes as smooth as expected. I have checked the optimized media files, they are generated on the same cache drive (NVMe).

One more strange thing - even though i use the same file settings (DNxHR HQX) for render cache and Optimized Media, the files generated by optimized Media have a bigger filesize (1352 KByte each Frame) than the files generated by RenderCache (904 KByte each). Is this to be expexted?

Did anybody encounter similar problems? Is it a bug? Any recommendations, or did i miss something basic here?


Thanks, Leif

I've had similar issues with network based media with EXR sequences. Only thing that has worked for me is to use the Fusion Render Cache rather than Render Cache.

Only thing I can find consistent with this is, if your media bandwidth can't be played in real time due to IO/O speed restrictions, you need to be able to play back in real time in the Fusion Tab within Resolve, if the bandwidth overhead is too much AND it can't playback inside of the Fusion time, the Render cache is useless. But if you force Resolve to read the EXR sequences through the Fusion Render Cache, they should playback in real time. All my tests show that the Fusion tab does not play back the EXR files in real time from the server or local, but the bandwidth is adequate when it's local on the edit page, but not when it's on the network.

Let me know if that works, I'm not exactly sure that's what's happening but haven't had anyone else comment or have success doing it this way.