tbMbp 2016 with LG Ultrafine 5k display, slow in Astropad


I know the display has been reported a lot due to EM shielding issues. However, I think my unit has been working fine.

I’ve noticed that whenever I’m using the 5k display (in clamshell mode), Astropad would slow the whole system down quite significantly. You can see the mouse cursor frame rate dropping noticeably, and the lag on ipad is almost unbearable.

When I’m only using the built-in retina display, everything works fine.

I wonder if it’s a hardware limitation where the AMD Radeon Pro 460 just can’t push that many pixels while running Astropad? Or is it a software optimization issue? I surely hope it’s the latter…


Are you using any apps to keep the Mac awake? Also, this slow down is over wifi connection? Or both USB and wifi?


hi Malyse, no I’m not using any special app to keep the Mac awake. I’ve been using USB connections all the time.

As soon as I have the Astropad Studio open on my mac and connected to the ipad client, the cursor would become slow, without exception. I’ve attached a screen recording.



forgot to mention. My system is 10.12.4 Beta (16E154a)

The stable release has some serious issues with the graphic driver especially when connecting to external displays, which is why i’m using the beta


Thanks for the video and added details.

In the Mac app’s preferences, if you disable "Allow connection via Wifi"
does it make any difference with this?


yes I’ve tried that. No difference


Is Airplay on at all? Or Airdrop enabled? What happens when you use Clamshell mode without Astropad?

In Astropad Studio’s sidebar, if you select General Settings, and turn off ColorSync, is there any difference?


airplay’s not active when i’m using it. Airdrop is enabled as always. I’ve always been using the laptop in clamshell mode when connecting to external displays.

it’s pretty obvious that the combination of astropad (both normal and studio version) and 5k display is causing the framerate drop. I’ve tested the following cases, all with USB connection only:

  1. internal retina display only: smooth with astropad running or not
  2. 5k monitor only, astropad studio desktop app open, but no ipad client connected: smooth as usual
  3. 5k monitor only, astropad studio desktop app open, and connected to the ipad client: this is where problems occur

turning on/off colorSync doesn’t make any difference what so ever.


Do you still have lag if you set the display to a lower resolution when using Astropad?


yes. no difference, and everything turns to normal when the connection to astropad studio is off.


@wooliudo These details help, it gives us a clearer idea of what’s going on.

This is thorough info, and great that you had tried with Astropad Standard as well.
We’ll have to look into this issue further, and improve for this setup.

Apologies for the inconvenience.


Has a fix been identified? I am having exactly the same problem with the 4K version


@Pro_Image_Editing What Mac model are you using with your display? As well as Mac OS and iOS?
We’re still trying to figure out why this is occurring.


hi Malyse, I’m using the macbook pro 15 inch late 2016, with amd radeon pro 460 and16gb of ram. The ios device is ipad pro 12.9 inch.

macOS version is 10.12.4 and ios 10.2. i’ll try it out again when it’s updated to 10.3


@wooliudo Thanks so much for the added details, definitely helps!
Again, we appreciate your patience with this issue.


did you ever fix this?
When I had similar issues, I had to run a sudo purge command in terminal. This will clear your RAM and disk cache. I would close all of my apps, run a sudo purge, and started astropad first to make sure it got the RAM it needed (I’m not an expert; I’m only reciting what worked for me).
I also found that certain apps running in the background were hogging up my resources, so i turned them off and decided to only open them when I needed them.
To see if anything funky is going on, open activity monitor, and view your running processes (view > active processes). Sort by % CPU usage. If something is taking up like, 99% CPU power, that’s probably frozen and causing a slow down.

Hmm, sorry if you already knew this or it didn’t help. Posting this because it might help someone else too.



We’re still looking into this issue. Thanks @saramations for these details, it all helps :slight_smile:

@wooliudo Using Mac OS 10.12.4, does the same slow down occur when not on the Beta version?

Also, is there the same slow down when unused programs are closed?


hi Malyse, since i’m no longer subscribing the studio version I can’t test if it’s working. But from my quick testing on the standard version, the performance seems to have greatly improved! Although there’s still a visible framerate impact, I might give the studio version another shot.


@wooliudo Thanks for update, and good to know this doesn’t happen with Standard.


I am having the same issue, Astropad studio and the standard is lagging when MacBook pro late 2016 is connected to LG 5k Display. Is fix coming?