Apple Catalina Appears to Introduce Massive Jitter - SOLVED!

Fri Oct 30 21:57:08 UTC 2020

I would hesitate to blame BT. I have a macbook pro from ~1 year ago, on 
Catalina, and I use BT extensively ... mouse, keyboard, and headset. I 
do have location services trimmed down to just find my mac.

I ran: ping -c 1000 -i 0.1 <router address>

1000 packets transmitted, 998 packets received, 0.2% packet loss
round-trip min/avg/max/stddev = 1.255/2.378/9.095/0.634 ms

One thing that may contribute to blaming BT however is if you are using 
wifi on 2.4G only, and/or preferring it, as BT operates in the same 
frequency range neighborhood. My macbook is connected using 5G.

Happy to compare other settings if there is interest.

Doug

On 10/30/20 12:08 PM, Mark Tinka wrote:
> Hi all.
> 
> So I may have fixed this for my end, and hopefully others may be able to 
> use the same fix.
> 
> After a tip from Karl Auerbach and this link:
> 
> https://developer.apple.com/forums/thread/97805
> 
> ... I was able to fix the problem by disabling Bluetooth.
> 
> However, disabling Bluetooth was not enough. I also had to disable all 
> Location Services.
> 
> After that, I re-enabled Location Services and only allowed for two 
> features:
> 
>      - NetSpot
>      - Find My Mac
> 
> With just those two location services, as well as Bluetooth disabled, I 
> have no more high jitter.
> 
> App performance like Zoom and Youtube uploads are now crisp, with 0.0% 
> packet loss.
> 
> So looks like that Bluetooth is a huge problem. Confirmed by opening the 
> "Console" app, and adding "scan" in the filter bar, top right.
> 
> A peak latency of 13.5ms after 300 packets:
> 
> Marks-MacBook-Pro.local (172.16.0.239) 2020-10-30T21:06:05+0200
> Keys:  Help   Display mode   Restart statistics   Order of fields   quit
> Packets               Pings
>   Host Loss%   Snt   Last   Avg  Best  Wrst StDev
>   1. 172.16.0.254 0.0%   300    3.1   4.8   2.2  13.5   1.9
> 
> Mark.
> 
> 