Pro Tools HDX and 4K monitors

[LukeHoward]

I'm seeing high CPU usage running at Ultra HD resolution, I can find one reference suggesting that this is a known issue (from last year) – any update on this, Avid?

I am on a MacPro5,1 (2010 6-core), Pro Tools 12.8.1, macOS 10.12.6, HDX, and in this case testing Fabfilter Saturn 1.17 with five bands. At a buffer size of 256 (at 96k), with just signal generator and Saturn instantiated, CPU is spiking up to 100% and the test tone is non-continuous.

What changed in my setup is upgrading my GPU to a RX 480 (and macOS to 10.12.6, which I know isn't qualified). I'm wondering if it's something to do with PCIe bus bandwidth. Switching to a CoreAudio playback engine seems to resolve the problem at the same buffer size, and switching back down to 1080p (so far) seems to make things better, although I need to do more testing. Obviously, putting the old GPU in is the next thing I'm going to try.

[Bob Olhsson]

My understanding is that high powered graphics cards will reduce CPU performance.

[LukeHoward]

Originally Posted by Bob Olhsson

My understanding is that high powered graphics cards will reduce CPU performance.

Thanks Bob – do you think this would still be an issue even when running at lower resolutions? Since switching back to 1080p, touch wood, it seems to be a bit better. I'm kind of trying to avoid having to put the old card back in...

[Bob Olhsson]

I have no idea but these things aren't nearly as linear as we'd like.

[LukeHoward]

Originally Posted by Bob Olhsson

I have no idea but these things aren't nearly as linear as we'd like.

Well said. I'll keep investigating.

[LukeHoward]

Has anyone tested 4K performance on High Sierra, anything improved?

[Extreme Mixing]

Why do you need to run the Pro Tools screen at such high resolutions? I can remember when running Pro Tools Version 5 or 6, we used to change the graphics from Millions of colors to Thousands of colors and it making a dramatic difference. I'm sure those things are the same. Processing is processing. If you want to spend it on 4K resolution of the monitor, that's your choice. But I would assume that you will pay a price in Pro Tools performance. There is a point at which you don't get any better view of Pro Tools, so why spend the processor bandwidth?

[LukeHoward]

I have a 4K display and it looks best at its native resolution. Sure, I can swap it out, but once you go Retina it’s hard to go back

[Extreme Mixing]

You are the one who has to decide whether having the power you need to mix without restrictions is important enough to go with the lower viewing resolution. Latency usually comes along with the package. Nothing bothers me more than having laggy meters. YMMV.

[LukeHoward]

I’m aware of that :) my question was whether anything had changed in High Sierra, that’s all.