DP10 and 4k monitor screen lag

[jlaudon]

Hi all

I have a 2018 Macbook Pro and bought an external Samsung 32" 4k monitor... I've tried many fixes, but there is a noticeable screen lag when dragging things in DP..like dragging pitch, resizing windows, even pressing key commands. I set to DisplayPort 1.2 on the monitor, have the latest and best USB-C to DisplayPort cable, tried resetting the scaled and default resolutions on the Displays Preferences, all to no avail. I hooked up my 27" 1080 monitor, and things are way speedier...

It feels like the 4k monitor is running at 60hz refresh rate for other software and the normal system/finder things, but in DP it slows down considerably, like 30hz refresh rate...

Has anyone else had this happen to them?

Thanks in advance for any advice

[mikehalloran]

Not enough information. Saying it’s a 4K monitor doesn’t tell us anything. There’s 4K SST, 4K MST and others...

30fps is not going to be an issue with DP. It’s not like gaming. There’s the possibility that you are trying to force 60fps with a monitor that doesn’t support it the way you are connected or requires a firmware update to be compatible.

Start with this Apple support bulletin. Be sure to follow the links.
https://support.apple.com/en-us/HT206587

I had two LG 4K monitors flanking my new iMac hooked up the same way and have no performance issues other than having to lower the brightness level so I wouldn’t go blind.

[bayswater]

When I got a 2018 Mini, I also got a Samsung 32" 4K to use with it. Mine doesn't run at 60fps at full resolution. As Mike says, with DP this shouldn't matter.

What mouse are you using? I also had some noticeable lag between mouse and screen that I hadn't noticed on my old 2009 iMac 27". It turned out to be my MX Anywhere 2 wireless mouse. I've gone to an old wired USB mouse and things are much better. Logitech sort of acknowledged the problem and offered me a discount on a new mouse, making me wonder if their older stuff doesn't work properly with the 2018 Macs or maybe with Mojave. I noticed my original trackpad doesn't work very well with this new Mac and monitor either.

Back to refresh rate, at some resolutions I can get 60 fps, but this doesn't make any difference to the mouse performance, or the general feel of DP.

FWIW, I rarely set the monitor to its native resolution with DP. Some things are too small. Rather than use the DP 10 scaling feature to make things bigger, I just use a lower screen resolution. In retrospect maybe a 4K should be at least 40" to make sense with apps like DP and Logic and certainly Mixbus, but I don't have enough room between my monitors.

[HCMarkus]

I've been running a 4k display (Samsung 40" TV) via HDMI for well over two years now. Under 4k, DP is laggy compared to just about everything else non-audio. Not sure what can be done about it; it seems like the issues may flow from DP's code. I have noted that Page Up and Down commands work quickly, better than scrolling down the track list.

Let me add that 60Hz monitor response makes a big difference when using any application. At 30Hz, the mouse feels very sluggish, no matter the app. Running Sierra, I am able to get 60Hz only by using a Display Port to HDMI active adaptor. Although I haven't tried it myself, others report that more current versions of macOS don't require so much hoop-jumping to get 60Hz via HDMI directly.

If using a TV, it is important to run it in gaming mode to get the best response times.

The 4k overview gives so much real estate to work with... despite the lag, I wouldn't go back to the smaller workspace 1080 provides.

[jlaudon]

Thanks for all your replies and thoughts.... my main issue is with pitch correction lag, which is very noticeable when I do a lot of moving notes around.. gets frustrating because of the lag.. other things in DP aren't so noticeable, but once I jump over to my 1080 monitor, I notice the difference immediately.

I know the monitor is running at 60hz, because in other applications and the finder, the response is pretty much the same as the 1080 monitor, when I resize windows for example.

In the end, even though there is way more real estate on the 4k, I ended up using DP on the 4k at the same size as my 1080 monitor purely because of my crappy eyesight. So my workaround is to use the 4k for all the open plugins as a secondary monitor, and my 1080 display for DP's main window and editing windows.

[jlaudon]

Interestingly... when I drag a note in pitch correction mode on the 1080 display, it is the fastest response, and when I do the same thing on the actual MacBook Pro display, it is ever so slightly slower.