FS7: DaVinci Resolve 12.1 Struggles With XAVC I UHD On My Mac

Erik Naso

Erik Naso

Veteran
DaVinci Resolve 12.1 is struggling to playback UHD XAVC-I footage. The audio skips and the image is freezing or just holds a frame them jumps forward. It's a mess. This is editing in Resolve not importing a XML. I want to use Resolve as a NLE. Edit and finish. Maybe it's just not ready for this but HD footage works very well.

I have a Mac Pro that I upgraded. Here is the full info on my upgrade.

Mac Pro Early 2009 MacPro5,1
10.11.2 (15C50) El Capitan
2 x 3.46 GHz 6-Core Intel Xeon

64 GB 1333 MHz DDR3 ECC

NVIDIA GeForce GTX TITAN X 12288 MB
The Titan X is flashed from MacVidCards
Nvidia Web Drivers 346.03.04f02
CUDA Driver Version: 7.5.22

This is a very capable machine now with the upgrade and Premiere Pro CC 2015.1 runs very well. Okay got the "Your system is to old out of the way." :lipsrseal

I can cut ProRes/Cineform UHD fine in DaVinci Resolve 12 but it struggles with FS7 XAVC-I codec. A big sell to me on the FS7 was the better 10 bit onboard codec and the files sizes are much smaller than shooting ProRes. if I have to buy the extension unit and shoot ProRes or transcode to use Resolve I'm going to be disappointed.

My playback settings in Resolve.
Proxy Mode - 1/4
Render Cache - Smart

I hope I'm not the only one having playback and sluggish performance with XAVC-I in Resolve 12.1. I did install 12.2 and it didnt fix the issue.
 
My 2010 Mac Pro handles HD fine but is less smooth with UHD in Resolve, it feels like it's having a tough time but still plays back at 25 fps. Nothing like your symptoms and my machine is nowhere near as upgraded as yours.

My iMac 5K wipes the floor with the Mac Pro and easily edits and grades UHD in Resolve. On paper my Mac Pro has more CPU and GPU grunt but in reality the iMac's fat wide bus is able to transfer XAVC-I off the SSD, into memory and onto the GPU much more efficiently than the old girl.

You don't mention what drives you are using and it might be worth checking you're getting the performance you think you're getting from them.
 
Nirv said:
My 2010 Mac Pro handles HD fine but is less smooth with UHD in Resolve, it feels like it's having a tough time but still plays back at 25 fps. Nothing like your symptoms and my machine is nowhere near as upgraded as yours.

My iMac 5K wipes the floor with the Mac Pro and easily edits and grades UHD in Resolve. On paper my Mac Pro has more CPU and GPU grunt but in reality the iMac's fat wide bus is able to transfer XAVC-I off the SSD, into memory and onto the GPU much more efficiently than the old girl.

You don't mention what drives you are using and it might be worth checking you're getting the performance you think you're getting from them.
Click to expand...

I'm averaging 202 MB/s read from my RAID 5. It's an esata RAID. I know it's not the fastest but yep My Mac Pro is limited to eSata.

I also have a RAID 0 internal 3 drive array that is all Western Digital Blacks. It's twice as fast at 410 MB/s READ. I'll transfer all the media over to it and see if that helps.
 
what might help is in project settings / image scaling / output scaling presets to uncheck "match timeline settings" and set it to HD. Set it back to UHD in the render tab.

On my iMac 5K end 2014 / M295X 4GB there is no difference from native media to proxy mode half / quater.
 
Good news!

After moving all the media to the internal RAID 0 I'm getting really good playback now. I feel kind of dumb because I should know better. Ugh. Good to know I need faster read speeds when editing XAVC. It's still compressed and needs the speed.
 
XAVC-I seems to be tricky....i can edit 4K from the FS7 no problem on my mbp in FCPX...its so good i almost can't get it to choke at all....resolve not so good....and i have heard that it is a pain on windows....
these old mac pros are just limited in the way the dat gets moved around.....the fastest chips, ram, gpu does not help if the "highways" in between are clogged because they are "single lane".....this is most obvious with all apple software incl FCPX because it is made for the latest hardware and the hardware for the apps....those old mac pros have been out of that loop for years....resolve handles it differently of course but the limitations are still the same....
iMacs are pretty incredible, inexpensive and keep their resale value really well....buy the latest top end and sell the old one, you would be amazed how little money that ends up costing you....
 
Paul schefz said:
iMacs are pretty incredible, inexpensive and keep their resale value really well....buy the latest top end and sell the old one, you would be amazed how little money that ends up costing you....
Click to expand...

I can't agree more. We are so impressed by the latest iMac that we're moving all 2D/Video work to them and only using the old Mac Pros as 3D renderers. The 5K wide gamut display is also worth mentioning too, it's awesome.
 
I use a Thunderbolt Raid 0 (always have a full back up copy) never had an issue, but I always like to transcode my footage to ProRes 422, I know Premiere and Resolve, FCPX edit UHD XAVC-I natively but playback and renders are just plain better with ProRes.

Harddrives are so cheap these days I see no reason not to transcode to a less processor intensive codec. I can spend weeks in the edit suite on a long project so every minute counts.

I use a 27" iMac 3.4GHz Intel Core i7
32GB RAM
NVIDIA GeForce 2GB

* I do wish I had gone for the 4GB graphics card option as NLE's now make great use of GPU's.

But yeah like most are saying these new iMacs are killers.
 
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