GPU memory usage maxed out in PT 2020

[TLK Tom]

Hi,

I'm having an issue in PT 2020 whereby after working for about 20 mins the VRAM on my GPU becomes maxed out and the session starts running like an absolute dog. The GPU core itself is running at around 2-3% and is not being taxed. I initially noticed this because I was getting a lot of fan noise after switching to a 5k screen and using Pro Tools, but it didn't seem related to the CPU/core temp (which I monitor routinely - it sits at around 70-78 degrees in a large session, and usually I won't hear the fan at this temp), so I watched the stats on the card from load until the session started becoming glitchy.

As soon as I quit Pro Tools the VRAM is freed up and the system returns to normal (and the fan spins down).

Specs:

MacBook Pro 2019 2.9ghz 6-core I9
32 GB RAM
GPU: Radeon Pro Vega 20 4GB
OSX 10.15.5
PT HD Native 2020.5 Thunderbolt w/4 x HD 16 IO via an OWC dock

This is a pretty new system, and the GPU is a good card.
No video in the session. The video engine is disabled, but the option to use GPU acceleration is enabled in prefs.

Currently running 1 x 5k LG UltraFine screen, which runs fine and never taxes the system at all apart from in PT 2020. The session is initially fine, it's almost as there is some kind of memory leak that builds up after a while and causes a frame rate drop/the GPU to heat up (and the associated fan to spin up).

To clarify, this is just a framerate/screen response issue, not an issue with cpu/buffer etc. Plugins are not affected bar redraw speed. Besides the display, ISTAT shows no dependants using the GPU other than PT 2020 and PT app helper (?!).

Anyone having any similar problems? I know there have been GUI issues with PT in the past... I am running the screen scaled, it's been fine in all other programs.

Any remedy suggestions welcome, thanks in advance.

T

[Darryl Ramm]

I have an identical MBP and display and will test later with 2020.5 and see if I see VRAM creeping up. What macOS version are you on? I've only got Mojave with me, Catalina drives are elsewhere.

[TLK Tom]

Sorry on Catalina 10.15.5 - updated original post.
Thanks!
T

[Darryl Ramm]

Nothing super-horrible happening after ~20 minutes of playing the PT demo session in a loop on 2020.5 on Mojave. Mix and Edit window opens across the external and internal screens and lots of plugin windows open animating meters etc.

VRAM memory steady at ~85% according to iStat. I get no loud fan spin up. Have not changed any defaults there.. but am in a nice cool A/C environment.

Does it do this for you with the demo session?

I can leave running overnight. May try Mojave later.

You may want to try moving all plugins out of the plugin folder and see if that changes behavior (plugins get to write their GUI in OpenGL and might trip stuff up).

[TLK Tom]

Thanks, no I haven’t tried the demo session. I will have to dig into it a bit harder to check individual plugs I guess. What external screens are you using and are you scaling or running a native resolution? I don’t know much about OpenGL, but I find it weird that the mem is maxed yet the gpu core is barely operating, still maybe that is a common presentation.

I guess if it was loading the gui of a plug-in into the Vram every time the plug-in window was opened and then not clearing it on exit that would use up the memory pretty quickly...

Will update after further digging.

Thanks

T

[Darryl Ramm]

Originally Posted by TLK Tom

Thanks, no I haven’t tried the demo session. I will have to dig into it a bit harder to check individual plugs I guess. What external screens are you using and are you scaling or running a native resolution? I don’t know much about OpenGL, but I find it weird that the mem is maxed yet the gpu core is barely operating, still maybe that is a common presentation.

I guess if it was loading the gui of a plug-in into the Vram every time the plug-in window was opened and then not clearing it on exit that would use up the memory pretty quickly...

Will update after further digging.

Thanks

T

I have the identical monitor to yours on a likely identical laptop, certainly the identical GPU. Which is why I thought I'd run a test. But right now I'm on Mojave not Catalina.

You don't need to try to work out which plugin might be suspect. You just need to whack them all and see if the problem is still there. Move *every* plugin out or the plugin folder. Trash prefs. Pro Tools will automagically put back the default plugins. Rerun your session, lots of plugins will be missing but just see what it does.

I knwo a little about GPUs but have no idea how Pro Tools and plugins really deals with OpenGL and VRAM, but it's certainly possible that a program leaks VRAM memory, especially texture memory.

[Darryl Ramm]

I ended up leaving the Pro Tools demo session running overnight on several nights. Running 2020.5 (standard) on a new install of Mojave. I do not see forever increasing GPU memory use reported in iStats, and the session does not get worse stability or glitch/slow graphics over time.

I can run the demo session at an IO buffer of 32, but it's slightly flakey, if I start opening other apps or abusing Pro Tools plugin windows I can cause a CPU error. At a buffer size of 128 I could abuse it pretty badly and it would keep working. Actually that kinda shows how powerful a modern laptop is, and how nice Pro Tools can be.

OK sure the demo session is light weight for a powerful 8 core laptop, even at an IO buffer size of 32 it's only cracking a few percent CPU use... and it's not tracking or not doing lots of stuff through the small IO input buffer, so its not a great test of stability... but it was useful to show that those plugins and session did not have show a GPU memory growth like being seen by the OP, even when left running overnight. So again I'd start by suspecting a plugin doing bad graphics/OpenGL things.

---

This was a new 2020.5 install on a clean install of Catalina, installed on the system is has the standard Pro Tools plugins, all the Complete Plugin bundle, all the Air effects and VI plugins and a few extras like BlueCat free bundle, but I did not install my usual Toontrack VIs or the BIAS Amp/Effects suite, or other plugins. I just wanted to keep stuff to very standard Pro Tools plugins. The system was fully optimized, including WiFi and Bluetooth off. Avid Link and cloud crapware is uninstalled like I always do. System is booted and everything running off an external Samsung X5 SSD. Disk cache set to 2 GB. Ignore errors was off. Dynamic processing was on.

I ran this overnight over three nights with every plugin in that demo session enabled and the GUIs for them all open and scatted across the LG and internal display. I ran with the edit window timeline zoomed in and scrolling to try to get the graphics to do a bit more. I also ran with no plugin GUIs open and just the mix and edit windows open... neither made much difference or caused problems. If I wanted to see lots of GPU memory used I could enable networking and open several Chrome browser tabs and get GPU memory usage to climb near 100%, otherwise Pro Tools alone got to around around 75% when running for a long time. All GPU memory measurements made using iStats. I seemed to be getting a bit lower GPU memory use on Catalina than a similar setup running on Mojave, but I wonder if I had left some other apps running in the background.

If the OP has a session that shows a problem I'm happy to test run it on my system... even if I don't have all the plugins.

My system:
MacBookPro15,3
8-Core Intel Core i9
2.3 GHz
Hyper-Threading enabled
32 GB
Radeon Pro Vega 20

With LG UltraFine 5K monitor and built in display both running (not mirrored).