[Cuis-dev] Running Cuis in a BBB rev C. (similar to RPi). a video performance check

Phil B pbpublist at gmail.com
Tue Jul 20 10:11:09 PDT 2021

Your review is on target for anyone thinking about running Cuis
interactively on SBCs this small.  However...

Cuis, and Smalltalk more generally, can run acceptably well in a truly
headless mode on machines that small if you're careful.  This means
thinking more in terms of things like ssh than remote desktop.  The thing
to remember is that the Squeak VM (especially video) was designed to run on
80's era hardware: a single core CPU with a dumb frame buffer and minimal
OS underneath it.  So for example all drawing is done in software.  Modern
computers are fast enough to hide a lot of the overhead of this approach,
but as you've seen it's all still there.  The only reason a Raspberry Pi
seems even remotely acceptable running a desktop GUI is that Linux (today)
inherently supports multiple cores and the desktop is GPU accelerated...
our VMs take advantage of neither out of the box.  (If you had to run
today's Linux on truly mid-90's era hardware, you'd run away crying.)

I've been running it on an old BeagleBoard-xM (512MB RAM, single core
processor @ 800MHz) for years but you have to be careful about what you run
and how you run it.  Ideally you don't want to run any UI at all on a CPU
this slow: close all windows (including the taskbar) and tune all
preferences for server usage.  Then do as much of your interaction as
possible via the command line and/or network sockets.  If you really must
have a Morphic UI, remember every draw call is going to hurt.  So at least
close the clock on the taskbar, if not the taskbar itself.  Don't overlap
windows in the VM as changes in one window will often cause redraws in
another etc.  It's still not going to be a speed demon, but will run
acceptably well for many tasks.

I understand this isn't the use case most are looking for, but mention it
as to not discourage others who might still want to use these smaller
devices with Cuis.

On Tue, Jul 20, 2021 at 6:25 AM Nicola Mingotti via Cuis-dev <
cuis-dev at lists.cuis.st> wrote:

> Hi guys,
> I just finished a little test showing how a Cuis can run in a BeagleBone
> Black Rev. C.
> which is a device similar to a RPi but most fit to electronics projects.
> . BBB is headless
> . I connect to BBB via VNC
> . There is no desktop environment, Cuis is the only graphical application
> running
> I need to do at least another test on a bigger machine
> to see what part of the sloppiness is due to VNC and what is due to a
> small CPU,
> but my temporary conclusion is that this kind of hardware is too little to
> work well in Cuis.
> here is the video:
> https://youtu.be/sDDrBXB4K6A
> bye
> Nicola
> --
> Cuis-dev mailing list
> Cuis-dev at lists.cuis.st
> https://lists.cuis.st/mailman/listinfo/cuis-dev
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