CPU runs at 100% when playing multicam sequence

[Producer storyteller]

Not sure if this is a premier issue or if it's my cpu/computer. When I play a multicam sequence, only four cameras synced, my cpu shoots to 100% and starts choking. When I am out of the multi cam sequence and just playing a regular timeline it runs at around 20% and plays fine. A few months ago this did not happen. This now happenes on any project that has a multicam sequence. Anybody have any thoughts? 

Computer Specs:

• Processor 12th Gen Intel(R) Core(TM) i9-12900KS 3.40 GHz
• Installed RAM 128 GB (128 GB usable)
• System type 64-bit operating system, x64-based processor
• Windows 11 Pro
• GPU: NVIDIA TRX A4500
• Motherboard: ASUS PRIME Z690-P
• Qnap RAID 5 storage with 10gb transfer cards in both the Qnap and the computer. Cat 8 cable. (Qnap has 1tb of cash)

[R Neil Haugen]

What media is involved? Codec, camera, framesize & framerate?

[Producer storyteller]

Hi Neil:

4 clips, specs below:

1. MXF, UHD, 29.97--111.98 GB
2. MP4, UHD, 29.97--44.00 GB
3. MP4, UHD, 59.94--69.38 GB
4. MP4, UHD, 59.94--51.60 GB

[R Neil Haugen]

Next obvious question is ... since MXF and MP4 wrappers can both hold long-GOP media ... are those clips long-GOP?

UHD long-GOP at 59.94fps is an absolute bear for the decoding/decompressing work for one stream. 

So ... if those are long-GOP files, that's maybe why your system is stressed.

FWIW ... I work for/with/teach pro colorists. Most of whom have "heavy iron" computer setups, with more spent on their calibration probes than most of us on our full systems  We're talking many fast cores, probably 256GB of RAM, cache and media on RAID arrays directly connected with mulitple 10GBe connections. 

Very few of them ever work with long-GOP media in grading. When they get it in the delivery of media from a client, they normally t-code that to maybe ProRes422 for grading. Because their systems can playback multiple streams of 8k Red or Arri, but will start slowing playback when H.264/5 long-GOP stuff hits the sequence.

This is in both Resolve and Baselight, btw.

[Producer storyteller]

ok, I'll see if making a proxy will help and then reconnect when done. Will let you know how it goes.

[R Neil Haugen]

ProRes or Cineform on the proxies  ...