back to article 2020 hasn't been all bad – a new Raspberry Pi Compute Module is here

The Raspberry Pi team has stuck with tradition by following its Pi 4 a year or so later with the Compute Module 4. Those expecting another DDR2 SODIMM sized board are, however, in for a shock. raspberry pi compute module 4 Industrial and commercial customers are important to the company: more than half of the seven million …

  1. Peter Mount
    Happy

    Still not pleasing some

    All morning I've seen people complain about the lack of USB3... totally ignoring that on the PI4B the USB3 is actually hogging the sole PCIe channel - some have hacked their pi's removing the controller to get at the PCIe.

    Unlike the earlier dev boards, the new one allows existing hat's with it (one of my gripes with the old ones) but again some complaining about that.

    It'll be interesting to see how one of these compares with the 4B & earlier CM models, I've just got to wait now until early/mid November for mine to arrive

    1. Anonymous Coward
      Anonymous Coward

      Re: Still not pleasing some

      I'm not too sure what business USB has on a compute unit, but what is the power draw of this? They just keep adding things to it and pretty soon it's going to just be an ITX board. Their competition from ST, Espressif, etc. (which I imagine sell way more units) are being bought for their power consumption and particular strengths, not because they are AIO devices. I mean do you really want semi-fast calculations and 2 monitors at the cost of higher power consumption?

      I'm not knocking it, please the more options the better. However, from a hobbyist point of view this device kind of has no place in IoT, its only strength seems to be signage. As someone using ESP32, I'm not seeing the allure (unless I want to run a couple 4k banners).

      1. Yet Another Anonymous coward Silver badge

        Re: Still not pleasing some

        > I mean do you really want semi-fast calculations and 2 monitors at the cost of higher power consumption?

        For some applications yes.

        For mass market embedded, you will be spinning up your own board with a carefully chosen SOC and your own software support.

        This is targeted at smaller markets and places where you would otherwise use a PC. Kiosks + signage for example. Places where you need an existing OS and apps ready to run.

        1. Anonymous Coward
          Anonymous Coward

          Re: Still not pleasing some

          "Kiosks + ..."

          If it had network anything out of the box I'd buy it as with just a little magic marker, I think one could get away with "NCRP", although I'm not too sure what the touch support is on armbian (or win10arm) to make a fully dependable PoS Kiosk.

          1. Richard 12 Silver badge

            Re: Still not pleasing some

            Remember that Android is a Linux kernel, and kiosks have fixed hardware so the touchscreen config can be hardcoded, same as it is on phones.

    2. Stoneshop

      Re: Still not pleasing some

      Unlike the earlier dev boards, the new one allows existing hat's with it (one of my gripes with the old ones) but again some complaining about that.

      You can find dev boards for the SODIMM CMx from a rather basic one that just offers the standard pin header, micro-USB (one data, one power), microSD slot, and a camera connector, to one with every interface broken out plus an area to plug Arduino shields in.

      On AliExpress.

      Of course.

    3. tcmonkey

      Re: Still not pleasing some

      Yes - seen the same. I for one am very pleased to have the PCIe instead of USB3. Means one can do SAS or other such more data-oriented interfaces. Most embedded tasks do not need really USB3, so definitely a step up.

    4. Cynic_999

      Re: Still not pleasing some

      Amazon are offering a 4B with 8GB RAM with next day delivery ... Bare bones for £90, and for an additional £10 you get a 32GB SD card, UK mains power adaptor, heatsinks etc.

      https://www.amazon.co.uk/Raspberry-Computer-OFFICIAL-PREMIUM-WHITE-UK-PLUG/dp/B089FWTY89/ref=sr_1_4

  2. Pete 2 Silver badge

    Forgotten memories

    > onboard eMMC Flash storage of up to 32GB.

    A feature that is sorely lacking in the "play" version of the Pi.

    It is something that other fruity-pi's have had for years. Boards that if they had any half-decent software, support, or user forums - would have eaten the Raspberry flavoured version for lunch, years ago.

    1. Yet Another Anonymous coward Silver badge

      Re: Forgotten memories

      The point of the Pi was NOT to have onboard installed os.

      If you have an installed system in a classroom you have to manage it. You can't give students root so you can't have them install or modify anything, you need security, anti-virus, backup, maintenance, updates, rules and punishments for breaking them. Deterring students from doing anything not explicitly specified in the lesson.

      The whole point of the Pi is to be like the 8bit micros of old. You screw up you just pop in a new image card and start again.

      1. Anonymous Coward Silver badge
        Mushroom

        Re: Forgotten memories

        As much as I agree, the SD form factor was ideal for the prototyping/teaching environment, I'd much prefer to have the option of copying to onboard flash for deployment.

        I've had too many SD failures, including having it physically dislodge. A call-out to push a card back in is not fun.

        A simple jumper (or solder bridge) to select boot device and a USB imaging system would alleviate the concerns about management.

        I've been playing with Pis since the first generation (when you had to solder a short over the poly-fuses to be able to do anything useful with it!), but the key word there is "playing". The SD card means that I very rarely use them for serious stuff. eMMC would change that.

        1. Wellyboot Silver badge

          Re: Forgotten memories

          I agree the SD is prone to getting bumped out of alignment but Pi4 (like the older models) can boot from USB these days, I use the tiny sandisk sticks that are only slightly bigger than the type-a connector.

        2. Wayland

          Re: Forgotten memories

          An NVMe slot would provide removable storage and speed.

      2. John Robson Silver badge

        Re: Forgotten memories

        "If you have an installed system in a classroom you have to manage it. You can't give students root so you can't have them install or modify anything, you need security, anti-virus, backup, maintenance, updates, rules and punishments for breaking them. Deterring students from doing anything not explicitly specified in the lesson.

        The whole point of the Pi is to be like the 8bit micros of old. You screw up you just pop in a new image card and start again."

        Why, in a classroom, would you do *anything* other than netboot them?

        1. Yet Another Anonymous coward Silver badge

          Re: Forgotten memories

          >Why, in a classroom, would you do *anything* other than netboot them?

          Apart from managing the server and credentials and which student's image is which

          One idea is that the Pi is cheap enough to have the same machine at home - so the kids can take an SD card to/from school and play at home, like we used to do with cassettes (but hopefully more reliable)

          1. John Robson Silver badge

            Re: Forgotten memories

            Single image on network that get students running when they have forgotten their SD card....

            Don't need multiple images... you might want an NFS server, with user directories, but accessing the schools smb share will work just as well - and they almost certainly already have one of those, could probably have the image log in via AD... and that is something that schools will certainly have.

            So no I don't think it's alot of effort - given that you are going to want some sort of network storage available anyway fo submitting work.

    2. Androgynous Cupboard Silver badge

      Re: Forgotten memories

      I've been running Pi's long enough that I've had several MicroSD cards fail after several years. This is not a big deal, just replace the card. Soldered on storage would make this a much bigger issue.

      I'm not a flash expert - I'll concede it could be the MicroSD format itself that's causing the issue. But my impression is Flash has a fixed number of write cycles, regardless of the form factor.

      1. Colin Critch
        Stop

        Re: Forgotten memories

        Standard SD cards will fail eventually if they do not have global or static wear levelling. If you are putting standard SD card into product you can not easily get to and replace you will be in a world of pain. There are techniques you can use like read into ram then never write which will make a standard SD card last a long time ( based on number of reboots). You could maybe use SPI flash for write storage instead with read and write disturb aware file-system or just use NOR flash with it’s slow erase time.

        If you are gong to use a standard SD card then chose one that has android run support A1 or A2 as the flash endurance will make it last longer (like Sandisk).

        So the way SD cards fail is that with read disturb multiple reads cause adjacent flash cells levels become harder to differentiate between a one or zero then you get bit flips on reads. These bit flips cause invalid files and file-systems, this makes your PI a bit flaky. If you reformat the SD card the it will be fine but the fact the pi can’t boot makes this difficult to solve remotely. If you are going to put PI in the field running from SD card make sure it has global wear levelling SD card as this is the only thing that can stop read disturb issues, they are expensive for a reason!

        1. Androgynous Cupboard Silver badge

          Re: Forgotten memories

          A belated thank you Colin for useful advice.

    3. John Robson Silver badge

      Re: Forgotten memories

      Whilst I could see the benefit of an optional eMMC on board previously... they *do* have pxe capability.

      With the additional memory on newer boards you can just network boot and run from ram/nfs.

      1. Anonymous Coward
        Anonymous Coward

        Re: Forgotten memories

        "With the additional memory on newer boards you can just network boot and run from ram/nfs."

        But see, now you just made and an argument for embedded as even with just 16MB, you could have four identical 4MB boot images with fail over :-/. I think it's just one of those things were you're better of having it and not using it.

        However, would you really use netboot with such a device that may or may not have a connection at any give time? But to kinda flip that, it would be nice if it already had at least BTLE as I suspect most of these will be tethered to some mobile connection (and ~200KB should be O.K.). Even though I have absolutely no practical purpose for this thing, I would buy the 1GB version if it had wireless anything out of the box.

        1. John Brown (no body) Silver badge

          Re: Forgotten memories

          "However, would you really use netboot with such a device that may or may not have a connection at any give time?"

          Absolutely, yes!! We need more of them like that out there to keep the Bok! Bork! Bork series of articles running and the author in beer tokens :-)

        2. John Robson Silver badge

          Re: Forgotten memories

          "However, would you really use netboot with such a device that may or may not have a connection at any give time?"

          For deeply embedded stuff you get the option of eMMC, but for general use the additional cost/complexity isn't worth it. If you are doing a lot of these things then you can buy small SD cards in bulk or use the compute module).

          All the places I have RasPis they are sat on a network.

          I baulk at the cost of the "proper" PoE hats, but might use a PoE -> USB doodad or two later this year.

          If there was an option to add one thing.. I'd vote for a PoE option rather than eMMC, but that rather defines the whole problem, the first 80% of features basically everyone can agree on, it's the other 80% of features that fragment the market and make none of the options viable.

  3. Mage Silver badge
    Boffin

    Interesting

    Very interesting.

  4. Anonymous Coward
    Anonymous Coward

    Compute Module continues to target industrial applications

    drone brain?! :D

  5. J.G.Harston Silver badge

    Seeing it plugged into the I/O board - gods, it's tiny!

    But the Pi really is this century's equivalent of a CPU IC back in the '70s. It's the difference between buying a wallwart and having to build a PSU from scratch for every project like when I worra lad.

  6. Elledan

    Still needs cooling

    Although the use of Mezzanine connectors instead of the SODIMM form factor is great for a tighter inter-board connection, it is fairly fragile. Admittedly the CM isn't really meant to be fondled with constantly, but it's something to keep in mind during development.

    Beyond that it's a shame that the cooling issue isn't addressed yet, unless I missed something. On the RPi 4 it's pretty much a requirement to install active cooling to ensure that the SoC doesn't thermally throttle when put under load. It would be great if the CM (and the RPi 4, for that matter) had some provision for an HSF installation that doesn't involve thermal glue.

    1. Richard 12 Silver badge

      Re: Still needs cooling

      The mounting screw holes resolve the mechanicals nicely, and give a standard fixing to mount a heatsink too.

      Much better than the SODIMM form factor. Excellent to see.

      It's usual to thermally bond the CPU to the case/chassis of this kind of industrial device. It's usually a pretty big lump of aluminium so works well with a basic copper thermal link. Or direct, if mechanically strong enough.

    2. uro

      Re: Still needs cooling

      The heat issue with the RPi4B is pretty shocking, aside from industrial use these are targetted towards getting kids into compute/robotics/etc and they could easily burn themselves if they touched the SoC.

      I did some benchmarks using openbenchmarking with the RPi4B to compare it against the Odroid N2 in performance and thermals:

      Stock : So hot it was thermal throttling all through the benchmarks - Min: 62C / Avg: 78.9C / Max: 85.2C

      With XL heatsink: cooler than stock but not a great improvement - Min: 55.5C / Avg: 74.91C / Max: 84.2C

      With a heatsink + Noctua 60mm PWM fan at 3.3v: Manageable - Min 35.1C / Avg: 43.92C / Max: 51.6C

      As Above but at 5v, diminishing returns - Min: 33.6C / Avg: 40.82C / Max: 47.7C

      Odroid N2 Stock (Comes mounted to a heatsink out of the box) - Min: 35.5C / Avg: 41.05C / Max: 48.7C

      The N2 blew the RPi4 away in benchmarks, it's currently in my living room operating wirelessly via a dongle as a CoreELEC/Kodi system attached to the TV and video playback is flawless on Netflix, Amazon Prime, Youtube, Twitch, plus I have the option to dual boot into Ubuntu should I feel the urge.

      Comparatively the RPi4B is not the great video playback device that the RPi foundation tout it to be as it drops frames and buffers all of the time, even when wired into eth - my RPi4B is currently running node bots and n8n for IoT stuff, which they are perfectly siutable for.

      Price wise the N2 is more expensive, but by the time you kit out a RPi4B with all the extra stuff you require just for it to run cooler then it is arguably more expensive than other SBC's like the N2.

      The Raspberry Pi Foundation really do need to sort the thermal issues with their products out before i'll dip into my wallet for another one when competing products are better, run cooler and are much more capable.

      1. James Hughes 1

        Re: Still needs cooling

        Run the latest firmware and most heat problems go away unless you are really hammering the ARM's. In general use they do not get hot enough to burn anything. So no, most people don't need active cooling. You are more than welcome to use it of course. It will prevent throttle under high constant workloads ARM (ie not video playback which runs cool as its done by the GPU). Not sure why you are seeing dropped frames, things like Kodi should run without anything like that.

      2. Silverburn

        Re: Still needs cooling

        To be fair, even a modest heatsink does wonders to improve the Pi4 thermals. I run a passive cooling case (the case acts as the heat sink), and even running a overclocked CPU at 100% for over two hours never saw it reach throttle temps. Under less aggressive workloads, it barely breaks 50'c.

        The heatsinks for the modules on the new Turing V2 look perfectly sufficient for sustained workloads (assuming even a very modest airflow; the power supply fan might even be enough).

    3. timrowledge

      Re: Still needs cooling

      Simply mounting the board vertically solves a lot of heat problems. It’s when you put a Pi4 in a box that you need to arrange some cooling. It doesn’t need much.

  7. cdrcat

    Beowulf cluster of 4 of these

    https://turingpi.com/

    “ Today we are thrilled to announce the Turing Pi V2. The Turing Pi V2 is s compact cluster in a mini ITX form factor with 4 x cluster nodes, 2x mini PCIe (Gen 2) ports, 2x SATA (Gen 3) ports, and new Raspberry Pi compute modules 4 support.”

  8. Silverburn

    Turing board v2

    The turing mini ITX board was a great concept for dense clustering; 7 pi3's in a mini ITX worked well (if somewhat lacking in actual horsepower). It will be interesting to see how they accommodate this new form factor.

    Edit: Looks like we know. https://turingpi.com/

    I would like to have seen stackable connectors, to allow a properly dense cluster to be built with these.

  9. That 8 Bit Guy
    Unhappy

    2020 hasn't been all bad

    "2020 hasn't been all bad"

    You are kidding right?

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon

Other stories you might like