I'd be curious to know if this is related to Pd itself *or* Tk? It appears to be the latter and the next test would be to write a minimal Tcl/Tk script which reproduces the behavior. It could be something like a single window with a Tk cnv and a rectangle which changes color in a loop. If the performance hit comes with just the Tcl script then we can open an issue with the Tk devs as there may be a regression.

On Jul 14, 2023, at 12:00 PM, pd-dev-request@lists.iem.at wrote:

Message: 3
Date: Thu, 13 Jul 2023 23:22:10 +0200
From: Roman Haefeli <reduzent@gmail.com>
To: pd-dev@lists.iem.at
Subject: [PD-dev] performance of different Wish versions
Message-ID: <1d9d56e5434211950cc1b1b363d84af42ff3b7f9.camel@gmail.com>
Content-Type: text/plain; charset="utf-8"

Hey all

I was seeing a suspiciously high CPU usage (~52% in Acitivity Monitor)
on macOS with one of my patches basically idling. It turned out to be
the GUI process and not 'pd'. Then I figured out that it was related to
frequently changing the color of a [cnv] in a GOP. The same patch with
the same rate of color changes eats almost no CPU on Linux (4-5% in
htop).  

--------
Dan Wilcox
@danomatika
danomatika.com
robotcowboy.com