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red_mamba
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Re: PI 4 Compute module with pci-e?

Tue Oct 08, 2019 7:14 am

Oh, and another thought. One user pointed this out already and I have similar idea.

Few years back we say the rise (and fall :D ) of PCI expanders that were used to connect PCIe-x1 signals to mining GPU cards.
What if you simply make a board taller and add USB3 connector exposing PCIe signals.

There are already PCIe hubs out there that split signals to 3 or 4 PCIe-x4 connectors (with x1 signals) for people that want to use it.
But also USB3 kables can be used to create custom PCIe boards for any use case you desire ;)

regards

jamesh
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Re: PI 4 Compute module with pci-e?

Tue Oct 08, 2019 8:52 am

red_mamba wrote:
Tue Oct 08, 2019 7:07 am
jamesh wrote:
Mon Sep 30, 2019 8:52 am
michalsykora wrote:
Sat Sep 28, 2019 8:51 pm
I like this discussion and I hope RPI foundation will listen to real world users.
We always listen. If I see stuff on here that I think is interesting and useful, I pass it up to the HW team. It's very rare that they haven't already considered anything I pass on.
James,

I had a plan for quite some time now to make rPi clustering easier for people to learn this sorts of things on a budget.
I'm working on CM3 version at the moment which is OS and can be seen and followed by anyone interested here: https://workspace.circuitmaker.com/proj ... M3-Cluster

The primary idea was to give users cheap way of testing and playing with docker/k8s and growing popularity of microservices.
But I see that 1GB of ram on rPi3 makes it unusable for any docker based OS. I tried balena OS and lack of ram is a big issue.

What I would like to see for CM4 is the ability to buy modules with different RAM sizes. 1, 2 and 4GB for example. Where for clustering 4GB would be the preferred choice and probably at least 8GB of storage, maybe 16Gb for OS.

The next thing that would be great to have is an easy way to route out signals for networking to connected it to a network hub that is integrated on the motherboard. I personaly thing that exposing PCIe signals should be given a serious thought as it gives users high speed access to SoC.
It doesn't matter what you connect to it at the end of the day as long as you have the choice to connect something :)

Also have you guys considered keeping the board size the same, but making PCB taller and maybe add gigabit LAN and USB chip on there and just route that signals to SODDIM connector. What ever can not be exposed directly can be exposed via board-2-board connectors. Which gives users the abillity to still connect extra monitor and stuff. I've seen SoM boards like this before. I just wouldn't go only b-2b connectors way as that eliminates the possibility of mounting the modules vertically and stack them tightly for clustering :)

my 51 sents ;)
Obviously I cannot comment on any future CM4 features, but have passed on your comments.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
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Gavinmc42
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Re: PI 4 Compute module with pci-e?

Sat Oct 12, 2019 12:19 pm

I think someone said a Model Pi4A has been ruled out?
And a Compute4 is still ????

That PCI-e hack that uses a USB3 cable gave me an idea.
Why not a Model 4A but with a USB 3 connector connected to the PCI-e pins.
USB2 via the USB-C like the existing Pi4B.

Still keep the Model 3A+ footprint, but with PCI-e for those that want to play with that feature.
Also have the dual HDMI?

Would a 4A+ wih PCI-e be of more use than a footprint same CM4?
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trejan
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Re: PI 4 Compute module with pci-e?

Sat Oct 12, 2019 3:58 pm

Gavinmc42 wrote:
Sat Oct 12, 2019 12:19 pm
Why not a Model 4A but with a USB 3 connector connected to the PCI-e pins.
USB2 via the USB-C like the existing Pi4B.
You're asking for trouble with that configuration. It looks like USB 3 but it is actually PCIe and you need a non-standard adapter to use it. If you want to plug in your USB keyboard then you're going to need to power the Pi 4 from the GPIO header and use a USB A to USB-C adapter. Support nightmare.

jamesh
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Re: PI 4 Compute module with pci-e?

Sat Oct 12, 2019 4:02 pm

Gavinmc42 wrote:
Sat Oct 12, 2019 12:19 pm
I think someone said a Model Pi4A has been ruled out?
And a Compute4 is still ????
Who said that?
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
"My grief counseller just died, luckily, he was so good, I didn't care."

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Gavinmc42
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Re: PI 4 Compute module with pci-e?

Sun Oct 13, 2019 12:28 am

I think someone said a Model Pi4A has been ruled out?
And a Compute4 is still ????

Who said that?
The decision was made that there will never be a Pi4A.
https://www.raspberrypi.org/forums/view ... 3&t=250303

Never say never?
A different connector than USB3 for the PCI-e?
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

W. H. Heydt
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Re: PI 4 Compute module with pci-e?

Sun Oct 13, 2019 1:17 am

Gavinmc42 wrote:
Sun Oct 13, 2019 12:28 am
I think someone said a Model Pi4A has been ruled out?
And a Compute4 is still ????

Who said that?
The decision was made that there will never be a Pi4A.
https://www.raspberrypi.org/forums/view ... 3&t=250303

Never say never?
A different connector than USB3 for the PCI-e?
If you follow the links, it goes back to the announcement blog entry. It does *not* say that a Pi4A has been ruled out. What it does say is that they haven't identified a less-than-$35 way to do it yet.

It is my *personal* opinion that there may never be a Pi4A, and--for similar reasons--there may never be a CM4. I think both will be worked on, but there are significant challenges that may not make either one economically viable. I think a Pi5A and CM5 are more likely, since by the time those would be feasible the RPT will be a lot more comfortable working though the issues around the radical hardware changes that have come with the Pi4B.

What I would like to see is a revision to the Pi2B to give a "Pi2Bv1.4" as basically an underclocked (say, roughly 1GHz) Pi4B without WiFi and--perhaps--only one HDMI connector. I doubt there would be enough market demand to support such a beast, but if such a thing hit the market, I'd get at least 6 of them and probably more like 10.

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red_mamba
Posts: 40
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Re: PI 4 Compute module with pci-e?

Sat Oct 19, 2019 2:02 pm

jamesh wrote:
Tue Oct 08, 2019 8:52 am
red_mamba wrote:
Tue Oct 08, 2019 7:07 am
jamesh wrote:
Mon Sep 30, 2019 8:52 am


We always listen. If I see stuff on here that I think is interesting and useful, I pass it up to the HW team. It's very rare that they haven't already considered anything I pass on.
James,

I had a plan for quite some time now to make rPi clustering easier for people to learn this sorts of things on a budget.
I'm working on CM3 version at the moment which is OS and can be seen and followed by anyone interested here: https://workspace.circuitmaker.com/proj ... M3-Cluster

The primary idea was to give users cheap way of testing and playing with docker/k8s and growing popularity of microservices.
But I see that 1GB of ram on rPi3 makes it unusable for any docker based OS. I tried balena OS and lack of ram is a big issue.

What I would like to see for CM4 is the ability to buy modules with different RAM sizes. 1, 2 and 4GB for example. Where for clustering 4GB would be the preferred choice and probably at least 8GB of storage, maybe 16Gb for OS.

The next thing that would be great to have is an easy way to route out signals for networking to connected it to a network hub that is integrated on the motherboard. I personaly thing that exposing PCIe signals should be given a serious thought as it gives users high speed access to SoC.
It doesn't matter what you connect to it at the end of the day as long as you have the choice to connect something :)

Also have you guys considered keeping the board size the same, but making PCB taller and maybe add gigabit LAN and USB chip on there and just route that signals to SODDIM connector. What ever can not be exposed directly can be exposed via board-2-board connectors. Which gives users the abillity to still connect extra monitor and stuff. I've seen SoM boards like this before. I just wouldn't go only b-2b connectors way as that eliminates the possibility of mounting the modules vertically and stack them tightly for clustering :)

my 51 sents ;)
Obviously I cannot comment on any future CM4 features, but have passed on your comments.
James,

can you also point them to SMARC 2.0 standard :)

https://sget.org/standards/smarc/

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