Blackmagic Forum

Just upgraded from buttery smooth v16 to v17.1b8 build 15 and the UI and playback are very slow. Audio is OK but video (timeline and clip = 1920x1080) stuttering and lagging. Dragging any window edge to resize, e.g. timeline, is laggy. Resizing whole app window is laggy. Even dragging the app across the desktop is laggy! V16 this morning showed none of this behaviour. It feels like just this one app is using a software renderer! Is anyone else seeing this? I have gone throught he forum and can't see anyone commenting on similar behaviour. App load speed is similar to v16.

That's the wrong version, it's optimised for M1. Get 17.0 beta 8.

Jeremy,
A link to logs (generated from the Help menu) and a video capture of laggy behavior if possible would help clarify the situation. Can I check if this behavior persists for later 17.0 or 17.1 builds?

Uli,
Resolve 17.1 betas are universal builds - offering native M1 support as well as native Intel Mac support. If run on an Intel mac, they should behave no differently than 17.0 betas.

Thanks
Shrinivas

Hello Shrinivas

Thanks for your reply. I attach a log as you suggest. I also downloaded the "latest" zip file from the main support page but it installed the same Build 15 as I was running yesterday. I'm pretty sure I noticed someone on the forum mentioning Build 23 but I don't know where to download that from. Anyway, (effectively) reinstalling Resolve has made no difference!

One thing I note my sig doesn't say is that I am on macOS 11.2 just in case that is important. I'll update that.

Hello Shrinivas

I've been trying to record the screen for you and have come up with some more info. Resolve is completely unusable on the MBP's own Vega 20 powered screen, not just laggy but full on choppy - worse than yesterday's tests. The audio is fine though. Recording the screen provided a completely black movie with just the mouse visible! I have to say that the screen recording process made the choppyness worse so it would not have shown a true representation of the problem anyway.

Moving the Resolve window to one of the screen plugged into my caged Vega 56 improved things dramatically the delay is almost imperceptable, though I would say it is still there (actually viewing the source material I now think there may be a sync problem with the audio there!!) and there is no dropping of frames. This is much better than yesterday's tests, but different to earlier tests today. The difference being that earlier today Resolve started up on an external screen - laggy. Just now it started on the laptop screen - very choppy. Dragged over to an external screen - almost OK. Hmm. So, I shut Resolve down while it was on the external screen, started it up and it started on the external screen - laggy!!!!!! Move to the laptop screen - very choppy. Move it BACK to the external screen - almost OK. Moving it back to the laptop screen - very choppy.

As a final test I disabled the eGPU and restarted my Mac with it disconnected. Resolve runs on the laptop's screen perfectly. Finally a clue? Is there an eGPU problem here?

I hope this makes sense.

Jeremy

Could it be a problem of having two different GPUs? DR is always limited to the GPI with the smaller VRAM, they don't add up.
I have a machine with two (nearly) identical GPUs and I don't see that behaviour.

Thanks for your reply Uli.

I tried disabling the Vega 20 from within Resolve but it made no difference, and both GPUs certainly worked under Catalina. And that's when the lightbulb came on.

This morning I tried disabling the internal Vega 20 and the external Vega 56. Nothing made any difference. With the eGPU plugged in the playback was choppy (slightly choppy on an external display, very choppy on either the laptop display or an external display connected to the laptop, not the eGPU).

So, I uninstalled R17, reinstalled R16, restored the R16 LocalDatabase backup and - the behaviour is exactly the same. So now the only difference is that R16 worked perfectly under macOS Catalina and neither R16 nor R17 work under macOS Big Sur - and then I had the forhead slapping moment - I had not run R16 since upgrading to Big Sur. I had backed up my databases under Big Sur with R16 but that hadn't involved playback. I then upgraded to R17, upgraded the database and started to use it - and came up against the problem.

No other app seems to be suffering this problem (that I have found yet). There is one difference though: dragging the R16 window around the desktop is always smooth but dragging the R17 window around the desktop was very choppy (if the eGPU is plugged in). Resizing is very slow for both R16 and R17 (I presume because it is actually trying to redraw the player), and R16 crashed trying just that. No offer of a crash dump though.

I have not reverted to Catalina for a test... I think this would be a proof but I simply don't have time.

So I must conclude that this is a problem with Resolve (of either version) playing badly with specifically macOS 11.2 and 11.2.1 and an eGPU (possibly specifically a Sapphire Vega 56 in a Razer Core X enclosure).

Now where do I go??? I feel that the title of this thread is now wrong, maybe I should start a new thread?

Jeremy

AFAIK the thread starter can change the title.
You may be onto something, the only system I tested under Big Sur is M1, and that doesn't support eGPUs anyway. But my Mac mini with eGPU is working fine with 17 under Catalina.

RESOLVED!

(excuse the pun)

Using the info from thread "17 and Big Sur update/ White screen EGPU" I unchecked "Prefer External GPU" from Resolve's Get Info page in Finder. Voila. That's all it took. This works for both R16 and R17 under Big Sur, I have checked them both.

The integrated Intel GPU didn't show up in Resolve's Preferences->System->Memory and GPU dialog (only the two Vega GPUs) the first time I ran the app, but subsequently it does. Rather wierdly it says "in use" but the playback perfomance suggests otherwise!

This does seem counter-intuitive, but definitely needs documenting very clearly somewhere - if it isn't a bug. It definitely wasn’t required under Catalina.

Jeremy

I'd consider it a bug, but is it on Apple's side or BM's?