OpenSCAD on Raspberry PI

classic Classic list List threaded Threaded
36 messages Options
12
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

JordanBrown
On 6/16/2020 7:32 AM, Rogier Wolff wrote:
But Moore's law says that transistors keep getting cheaper, ...

Moore's law is an observation, not a law of physics.  There's nothing that says that it will continue.


_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
tp3
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

tp3
In reply to this post by MichaelAtOz
On 16.06.20 05:35, MichaelAtOz wrote:
> Does this overcome OpenGL ES

No, it just uses the fact that Debian decided to stay
with Qt5+OpenGL as default on ARM64 and provide Qt5+GLES
as additional package. (Thanks!)

Unfortunately ARM32 continues to be GLES only so it
needs building a separate Qt5. This is possible, but
making that happen as automatic build eats too much
time I don't have anyway. So I'm not sure if it will
happen at some point. Right now, I tend to think it's
not worth the effort.

It's probably more useful to think about how to move
forward into direction of Vulkan.

ciao,
  Torsten.


_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
-- Torsten
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

thehans
In reply to this post by nophead
On Tue, Jun 16, 2020 at 6:44 AM nop head <[hidden email]> wrote:
Yes I was wondering the same thing. My PC is a few years old now but OpenSCAD is the only program I wish it was faster for. I do have a faster Linux machine but I develop using a database on Google Drive and Google don't do a Linux version. 

A bit off-topic, but yeah it's really disappointing that Google still refuses to support Drive for linux.  But there are options!  I use a 3rd party app called insync ( https://www.insynchq.com/ ) which syncs up my Google Drive to Linux Desktop.  It's not free, but worth the price IMO.

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

doug.moen
In reply to this post by tp3
On Tue, Jun 16, 2020, at 3:32 PM, Torsten Paul wrote:

> On 16.06.20 05:35, MichaelAtOz wrote:
> > Does this overcome OpenGL ES
>
> No, it just uses the fact that Debian decided to stay
> with Qt5+OpenGL as default on ARM64 and provide Qt5+GLES
> as additional package. (Thanks!)
>
> Unfortunately ARM32 continues to be GLES only so it
> needs building a separate Qt5. This is possible, but
> making that happen as automatic build eats too much
> time I don't have anyway. So I'm not sure if it will
> happen at some point. Right now, I tend to think it's
> not worth the effort.
>
> It's probably more useful to think about how to move
> forward into direction of Vulkan.

There was a status update on the Raspberry Pi 4 Vulkan port last week:
https://www.raspberrypi.org/blog/vulkan-update-now-with-added-source-code/
That's good progress after 5 months of work.

There won't be a Pi 3 Vulkan driver, so a Vulkan version of OpenSCAD will only run on Pi 4.

Torsten also wrote:
> What would be awesome:
> Fast multi-threaded algorithm with GPU support :-)

The GPU on the Pi 4 has 8 cores, each core is 4-way SIMD (compared to 4 CPU cores). So, rendering on the GPU would probably give the best performance.

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

OpenSCAD mailing list-2
In reply to this post by rew

You can set them up to boot off a TFPT server and run diskless with no SD card and then they can only work in their own scratch area on a shared disk. and the Pis boot a clean image each time they are powered on.
Only downside is that they need to be on a hardwired network.
Small SD cards are very cheap and you can supply a class with 4Gb cards for less than the cost of a softdrink each.
Once the WiFi sets up during the boot, you can share a file server with read-only areas and shared per student areas.



On 2020-06-16 10:15 a.m., Rogier Wolff wrote:
On Tue, Jun 16, 2020 at 01:50:22PM +0000, Doug Moen wrote:
I haven't tried running a Raspberry Pi based makerspace for kids.
But, I imagine that you can just give each student their own Pi,
and swap out the SD card if the OS gets corrupted.
Or you tell everybody to bring their own SD card. (or supply everybody
with...)

	Roger. 


-- 
Ron Wheeler
Artifact Software
438-345-3369
[hidden email]

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

OpenSCAD mailing list-2
In reply to this post by nophead
If the SDs are only used for boot, they should not get corrupted and should not contain the students' files.

Ron

On 2020-06-16 10:22 a.m., nop head wrote:
The SD sockets on RPI's are not very robust in my experience. It might be better for them to bring their own USB stick.

On Tue, 16 Jun 2020 at 15:15, Rogier Wolff <[hidden email]> wrote:
On Tue, Jun 16, 2020 at 01:50:22PM +0000, Doug Moen wrote:
> I haven't tried running a Raspberry Pi based makerspace for kids.
> But, I imagine that you can just give each student their own Pi,
> and swap out the SD card if the OS gets corrupted.

Or you tell everybody to bring their own SD card. (or supply everybody
with...)

        Roger.

--
** [hidden email] ** https://www.BitWizard.nl/ ** +31-15-2049110 **
**    Delftechpark 11 2628 XJ  Delft, The Netherlands.  KVK: 27239233    **
The plan was simple, like my brother-in-law Phil. But unlike
Phil, this plan just might work.

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

-- 
Ron Wheeler
Artifact Software
438-345-3369
[hidden email]

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

OpenSCAD mailing list-2
In reply to this post by rew
I believe that the Pi's ARM is a RISC architecture so that less gets done on each cycle but the cycles come quicker!

On 2020-06-16 10:32 a.m., Rogier Wolff wrote:
On Tue, Jun 16, 2020 at 02:59:35PM +0100, nop head wrote:
I don't think the number of cores makes much difference unless you have
multiple instances open.
So... for Openscad, to be able to make better use of the available
performance on the pi, a "roadmap" for openscad might include: "make
better use of multiple cores". 

Keep in mind that intel hit peak-clock-frequency somewhere around a
decade ago. But Moore's law says that transistors keep getting
cheaper, so even though still significant improvements keep being made
in how much work can be done in each CPU clock cycle, in the future
we'll be getting more and more cores in a chip. Currently even the
cheap hardware (e.g. pi) has four cores because they don't know what
otherwise to do with the available transistors!

	Roger.


-- 
Ron Wheeler
Artifact Software
438-345-3369
[hidden email]

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

OpenSCAD mailing list-2
In reply to this post by nophead
The cores might not help but my suggestion of a multi-computer workstation with a single keyboard, mouse and screen with a bank of slave Pis that could render the parts in parallel while you caught up on your email, would mean that your whole render job would only take as long as your longest render (given you have enough Pi4s).
For less than the price of a new workstation, you could probably put together a 4 or 8 Pi4 box, power supply, shared 1 terabyte networked drive and USB switch for the keyboard and mouse giving you the ability to run 8 renders or previews in parallel.

You do not even need the keyboard/mouse switch if you can script a rendering process that every 2 seconds wakes up and looks for new files in a certain location on the shared drive and automatically renders anything that the Pi4 finds that you have put there and moves the input drawing and the results to an output folder when the render is finished.

I cannot see why every CAD person would not want a bank of render slaves!

Ron

On 2020-06-16 10:53 a.m., nop head wrote:
There are experimental versions of OpenSCAD using multiple cores for rendering but that isn't what is slow for me. I do all my work in preview mode and only render the STLs to print them. Most don't take long, especially compared to printing them. E..g 38 parts to make a 3D printer take 7 minutes to render individually. The slowest one is the shelf bracket at 78 seconds, most take less than 10s. Drawing the preview from scratch, which does render() some of the parts takes 4 minutes. The killer is every simple change takes at least 23 seconds to redraw currently. Most of that time is running the script, so hard to see how multiple cores would help that.

On Tue, 16 Jun 2020 at 15:32, Rogier Wolff <[hidden email]> wrote:
On Tue, Jun 16, 2020 at 02:59:35PM +0100, nop head wrote:
> I don't think the number of cores makes much difference unless you have
> multiple instances open.

So... for Openscad, to be able to make better use of the available
performance on the pi, a "roadmap" for openscad might include: "make
better use of multiple cores".

Keep in mind that intel hit peak-clock-frequency somewhere around a
decade ago. But Moore's law says that transistors keep getting
cheaper, so even though still significant improvements keep being made
in how much work can be done in each CPU clock cycle, in the future
we'll be getting more and more cores in a chip. Currently even the
cheap hardware (e.g. pi) has four cores because they don't know what
otherwise to do with the available transistors!

        Roger.

--
** [hidden email] ** https://www.BitWizard.nl/ ** +31-15-2049110 **
**    Delftechpark 11 2628 XJ  Delft, The Netherlands.  KVK: 27239233    **
The plan was simple, like my brother-in-law Phil. But unlike
Phil, this plan just might work.

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

-- 
Ron Wheeler
Artifact Software
438-345-3369
[hidden email]

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

OpenSCAD mailing list-2
In reply to this post by tp3
The biggest pi4 is 4Gb and costs about $60 which is a lot less than 250 Euros
You don't need the monitor if it is only doing rendering.

Look at it as a notebook accessory for rendering.
Less than the cost of an ergonomic mouse or webcam.

Ron


On 2020-06-16 10:54 a.m., Torsten Paul wrote:
On 16.06.20 15:57, jon wrote:
This all makes sense.  What I am not clear on is how much
of a performance hit I would take vs my 8 core 4 GHz desktop
Unless someone completes the "Multi-threaded Geometry
rendering" issue (earning the current bounty of $1060),
the number of cores does not matter much.

So comparing my 2 years old Dell XPS 13 with i7-8550U
@ 4GHz max using the Menger Sponge level 3 example, I
see (even including the monitor in the Raspi price):

Notebook   | Raspi 4 (8GB) | Ratio
---------------------------------------
35 seconds | 2:46 minutes  |   1 : 4.7
~2200€     | ~250€         | 8.8 : 1

I guess the performance hit is not as bad as one
would imagine while the price is very nice.

I certainly would not suggest using a Raspi for very
complex stuff, but there's lots of things that it will
be able to do in a reasonable way. Especially when
looking at the 64bit/8GB model.

ciao,
  Torsten.

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

-- 
Ron Wheeler
Artifact Software
438-345-3369
[hidden email]

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
tp3
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

tp3
On 16.06.20 20:37, Ron Wheeler via Discuss wrote:
> The biggest pi4 is 4Gb and costs about $60

Ahem, obviously not, as the one I tested on
has 8GB :-).

https://www.raspberrypi.org/blog/8gb-raspberry-pi-4-on-sale-now-at-75/

ciao,
  Torsten.

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
-- Torsten
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

OpenSCAD mailing list-2
Cool.
I have 10 of the 4Gbs. Should have waited???

Actually 4 is a lot of memory for single purpose computers. I am going to run ISP functions and microservices.
Since I currently have Postfix-Dovecot, SVN, Web Gateway, and a few other things running on a 10 year-old 2gb server.
I am pretty sure that I can split this over a couple of 4Gb Pis and come out ahead.

As an OpenSCAD rendering accessory for a notebook, it should have memory to spare with 8GB.

Have you run OpenSCAD on it?
What OSs have you tried? I would like to have CentOS on it but so far as I know there is no official distribution for the ARM-72.
I have tried a few others.
A headless Raspbien should be fine as a basis for a rendering machine.

Ron

On 2020-06-16 2:44 p.m., Torsten Paul wrote:
On 16.06.20 20:37, Ron Wheeler via Discuss wrote:
The biggest pi4 is 4Gb and costs about $60
Ahem, obviously not, as the one I tested on
has 8GB :-).

https://www.raspberrypi.org/blog/8gb-raspberry-pi-4-on-sale-now-at-75/

ciao,
  Torsten.

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

-- 
Ron Wheeler
Artifact Software
438-345-3369
[hidden email]

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
tp3
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

tp3
On 16.06.20 22:23, Ron Wheeler via Discuss wrote:
> Cool.
> I have 10 of the 4Gbs. Should have waited???

Unless you have some extra heavy work load it should
not matter that much. More RAM is always nice, of cause,
but it does come with the higher price as well so it's
not directly replacing the 4Gb model.

> Have you run OpenSCAD on it?

Just a little bit for testing the AppImage and running
the speed comparison.

> What OSs have you tried? I would like to have CentOS
> on it but so far as I know there is no official
> distribution for the ARM-72.

Only Raspberry PI OS (64-bit) Beta so far. Just got
the new PIs for a work project. I have a 4Gb model
running headless as podcast downloder + NAS for a
while though and that works just fine.

> A headless Raspbien should be fine as a basis for a
> rendering machine.

Yep, I hope once the release happens it will also
come in that lite version which is great for that.

ciao,
  Torsten.

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
-- Torsten
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

Alan Cox-2
In reply to this post by OpenSCAD mailing list-2
On Tue, 16 Jun 2020 14:15:11 -0400
Ron Wheeler via Discuss <[hidden email]> wrote:

> I believe that the Pi's ARM is a RISC architecture so that less gets
> done on each cycle but the cycles come quicker!

You believe wrongly. That stopped being true around the time of the AMD
K6. RISC designs were at one point doing more per clock. Often they did
one instruction per clock or per two clocks when the 486 or Pentium took
several to do something. Today performance processors are quite different
to either historic RISC or CISC and in fact are much alike internally.
They do multiple instructions per clock regardless of instruction set.

Today's great battle is a three way battle between massively parallel
simple units, lots of conventional small processors, and larger
processors with more parallel instructions. Smaller transistors but no
huge clock rate/thermal improvement effectively means the question is 'how
do you do parallelism best ?'

The first is GPU, the second is AMD x86 and most performance ARM, the
third is stuff like Intel with AVX512 and the like plus systems like
Power.

The Pi is however none of these. It's a slower, cheaper and smaller
processor design fabricated on what is now a very old but reliable
and low cost process. It's designed for something quite different and
fills a set of market spaces that performance processors do not. It's
very low cost, it interfaces easily to 3.3v parts, it has very low
cost supporting glue and PCB design - hence the way it makes the Pi work.

Phone processors are different again being designed for very high
integration, burst performance and very low power.

There are also then processors designed to be good at continually having
work to do slowly but efficiently - eg in the telco space.

Alan

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

OpenSCAD mailing list-2
Great info.

Shows my age!!!
I thought that 2015 was just yesterday!
It is appalling to hear 2015 decribed as "very old".

I run my little datacenter on CPUs built as far back as 2007.

No wonder I think that the Pi4 is fast!

Ron

On 2020-06-16 6:27 p.m., Alan Cox wrote:
On Tue, 16 Jun 2020 14:15:11 -0400
Ron Wheeler via Discuss [hidden email] wrote:

I believe that the Pi's ARM is a RISC architecture so that less gets 
done on each cycle but the cycles come quicker!
You believe wrongly. That stopped being true around the time of the AMD
K6. RISC designs were at one point doing more per clock. Often they did
one instruction per clock or per two clocks when the 486 or Pentium took
several to do something. Today performance processors are quite different
to either historic RISC or CISC and in fact are much alike internally.
They do multiple instructions per clock regardless of instruction set.

Today's great battle is a three way battle between massively parallel
simple units, lots of conventional small processors, and larger
processors with more parallel instructions. Smaller transistors but no
huge clock rate/thermal improvement effectively means the question is 'how
do you do parallelism best ?'

The first is GPU, the second is AMD x86 and most performance ARM, the
third is stuff like Intel with AVX512 and the like plus systems like
Power.

The Pi is however none of these. It's a slower, cheaper and smaller
processor design fabricated on what is now a very old but reliable
and low cost process. It's designed for something quite different and
fills a set of market spaces that performance processors do not. It's
very low cost, it interfaces easily to 3.3v parts, it has very low
cost supporting glue and PCB design - hence the way it makes the Pi work.

Phone processors are different again being designed for very high
integration, burst performance and very low power.

There are also then processors designed to be good at continually having
work to do slowly but efficiently - eg in the telco space.

Alan

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

-- 
Ron Wheeler
Artifact Software
438-345-3369
[hidden email]

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

OpenSCAD mailing list-2
In reply to this post by tp3
Thanks for sharing.

The price is pretty low for the extra 4Gb, if you have an application that can use caching or a lot of in-memory temporary data.

I purchased a Bitscope rack that will hold 20 Pi4s and have designed a power supply to support it but COVID hit just about the time I was ready to do some 3D printing and laser cutting for an acrylic case
at my local Fablab (Public Library) to mount these in my rack.

Given that a lot of my current servers are 4Gb or less and with Kubernetes/Docker I can build a multi-CPU platform for microservices, I am looking forward to migrating to a physical cluster where physical Pi4s replace VMs that are made from dividing up larger more expensive servers.
At $55 per physical VM, why bother with virtual VMs.
In a 4U rack, one can actually get 40 Pi4s. That is a lot of power in a 4U rack for less than $3,000 USD.
Would make on heck of a rendering farm for an office of designers.

With 8GB, one could actually break a Pi4 into 2 or 4 VMs, so that is even more flexibility if your applications are not CPU-bound.

Ron

On 2020-06-16 5:15 p.m., Torsten Paul wrote:
On 16.06.20 22:23, Ron Wheeler via Discuss wrote:
Cool.
I have 10 of the 4Gbs. Should have waited???
Unless you have some extra heavy work load it should
not matter that much. More RAM is always nice, of cause,
but it does come with the higher price as well so it's
not directly replacing the 4Gb model.

Have you run OpenSCAD on it?
Just a little bit for testing the AppImage and running
the speed comparison.

What OSs have you tried? I would like to have CentOS
on it but so far as I know there is no official
distribution for the ARM-72.
Only Raspberry PI OS (64-bit) Beta so far. Just got
the new PIs for a work project. I have a 4Gb model
running headless as podcast downloder + NAS for a
while though and that works just fine.

A headless Raspbien should be fine as a basis for a
rendering machine.
Yep, I hope once the release happens it will also
come in that lite version which is great for that.

ciao,
  Torsten.

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

-- 
Ron Wheeler
Artifact Software
438-345-3369
[hidden email]

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: OpenSCAD on Raspberry PI

cacb
In reply to this post by nophead
On 16.06.2020 15:59, nop head wrote:
> I don't think the number of cores makes much difference unless you have
> multiple instances open.

It should indeed matter, because OpenSCAD is to my knowledge not running
booleans in parallel threads. If so it will onbly be using 1 out of 4
CPUs in the PI 4. AngelCAD on the other hand should be able to use all 4
CPUs, like on any PC. But still, this is not

Carsten Arnholm



_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
12