Raspberry Pi CM5 seen in the wild | Hacker News Reader

Raspberry Pi CM5 seen in the wild

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53 pointsceinewydd37 comments

We all knew this was coming, but my question is what's the topology? The same as the regular Pi5, with the RP1 southbridge built-in and only one PCIe lane exposed for the user, or does the CM5 leave off the RP1 and break out all five PCIe lanes for user shenanigans? They have a bare chip supply chain set up from the RP2040, so they could sell the RP1 separately for those who want to integrate it onto their carrier boards.

It looks like the CM5 still has one PCIe lane. https://pip.raspberrypi.com/categories/945-forward-guidance

Be aware that discussing anything in the CM5 Forward Guidance document is tricky, the document still says -

"This whitepaper is restricted and covered by the Raspberry Pi Ltd non-disclosure agreement (NDA). It should not be copied, shared, or duplicated without permission."

Good thing nearly none of us here have signed that NDA.

I signed up with a disposable email and got access automatically, it's not that secret evidently. It was probably stricter earlier in development.

I kinda don't understand the point of the CM5. If you want a SoM, you're generally building something "fancy" around it… and at that point anything involving Broadcom is just about the worst choice.

I guess it gets some bump from the shared platform with the Pi, but… there's enough SoMs with good platform support at this point. And it's not like they're notably cheaper than those either?

(ed. I guess they are still cheaper than competing SoMs with roughly equal performance… but you pay the price of a poor closed platform instead)

> there's enough SoMs with good platform support at this point

You’re talking about the new (and expensive) Turing RK1 and the Nvidia Jetson as alternatives?

Turing RK1 and similar, nVidia not as much given their platform accessibility is barely better than Broadcom. RK1 is not particularly great either but significantly better than either Broadcom or nVidia.

I agree the really well supported platforms are both older as well as more expensive (e.g. i.MX & Sitara platforms.) However, I won't call the RK1 "expensive" considering it outperforms the Raspberry Pi (5) by a larger factor than it is pricier by (roughly.)

[Ed.:] Actually, no, the RK1 isn't better either, given there doesn't even seem to be a datasheet available for the module as a whole.

I guess I'm just living in my expensive but well-supported world of NXP, TI and ST SoMs that I can actually debug…

CM stands for compute module, for those wondering like me

Did anyone grab a screenshot or copy of this before it was deleted? Archive.is/archive.org don't seem to have it.

Snapshot by link caching app:

https://imgur.com/a/EkcXHGh

Went down the voice assistant rabbit-hole with Home Assistant. To integrate with an LLM, you will need a separate processor (or connect to the cloud service).

Wondering if CM5 will offer enough of a boost to allow on-device LLM processing on a Home Assistant Yellow.

Guessing the answer is no, but it might be worth trying.

Orange Pi.

Are we 100% sure that this picture of a CM4 box with a CM5 sticker slapped on it is legitimate?

Here's the official CM4 => CM5 technical guidance: https://pip.raspberrypi.com/categories/945-forward-guidance

What does this mean for someone non-technical who uses a Pi for home files server?

Nothing.

Okay, I'll bite: what's going on? Seriously. I know what a Raspberry Pi 5 is, I have one. No idea what I'm supposed to take away from a "CM5"

CM5 is just shorthand for Compute Module 5. It's a raspberry pi 5 in a different form factor. Until it's released we can't know all the exact differences without apparently signing up for an NDA'd spec sheet. But see https://www.makeuseof.com/raspberry-pi-4-vs-raspberry-pi-com... for a breakdown of how the PI 4 and CM 4 differed.

I've been waiting for this, now, the question is, is this a drop-in replacement for the CM4? If so, these will sell really well (and will have shortages)

What's something you do with these compute modules (CM)?

They get installed in stuff like the Home Assistant Yellow, or the Timecard Mini.

https://www.home-assistant.io/yellow/

https://www.jeffgeerling.com/blog/2023/time-card-mini-adds-p...

Build products with them. I know of a few musical instruments with CM3s, for instance.

I use one on a "CM4 ETHER BOARD" https://dphacks.com/cm4-ether-board-minimalist-compute-modul... which provides Ethernet, USB-C for power and micro USB for flashing an EEPROM. It doesn't have an SD card slot but it has a 2230 NVME slot on the reverse side. I program the SSD on another setup and run Home Assistant on it. Ethernet is really all the I/O needed for a small server like that.

I have another one on a Bicool Mini Base Board (A) which has a lot more I/O, albeit only one HDMI port and no USB3. It's suitable for desktop type applications with the caveat that the CM4 is barely suitable for that stuff.

Something which would most likely to be too niche of a market but which I would spend almost unreasonable money on would be a framework like laptop which one could upgrade by popping in a new cm every other year.

Hmm, Intel Compute Card strikes back? Doesn't sound terrifically practical (even the RPi 5 is kind of anemic as a desktop...)

RPi 4 and 5 Tablet, https://www.raspberrypi.com/news/this-is-the-worlds-first-ra...

Digital signage, among others. Think big flashy LED screen in store window, train station & the like. Or kiosk-style uses.

Also I've read some e-scooter sharing company used CMs for the smarts in their vehicles. Edit: might have been RPi's not CMs (but the latter wouldn't be out of place).

In short: industrial & embedded uses.

A friend of mine builds synthesizers with them: https://www.tastychips.nl/product/gr-1-granular-synthesizer/

Currently it runs my home assistant installation at home, so, a bit more processing would help, but it is not a critical load that requires speed most of the time. The most annoying task is compiling ESPHome firmwares from the raspaberry, which could take several minutes.

Eben Upton was refusing to be drawn on specifics when Jeff Geerling and others chatted to him [1] about roadmaps recently. Nevertheless, the rumor is that CM5 will be drop-in compatible with the CM4, the details of that have been available via their NDA portal [2] for a few months now, but I think even this leak on Twitter (just a box with a label) is a breach of an NDA / embargo, so we might not know officially for a little bit yet?

[1] https://www.tomshardware.com/raspberry-pi/raspberry-pi-compu...

[2] https://pip.raspberrypi.com/categories/945-forward-guidance

Will it be compatible with things like the CM4 I/O board?

If CM5 doesn't at minimum expose the PCIe x4, I'm going to flip some fucking tables over.

The trouble with these CM's is by the time you get your hands on CM5 and engineer your custom carrier board for it (because they change the pinout every time), Pi 6 has come out.

Hopefully they're sticking with the same connectors and pinout as the CM4. The Raspberry Pi foundation considers the Compute Module line to be non-hobbiest-oriented anyway. They expect people to be building around the solution offered as a long-term product. The NEC display is a good example, because NEC is interested in driving the display for the life of the display, not in customers replacing the CM4 when its EOL.

It won’t fit into rpi 400?

The Raspberry Pi 400 is a distinct product. It doesn't use a Compute module internally.

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