New Raspberry Pi Compute Module 3+

https://www.raspberrypi.org/blog/compute-module-3-on-sale-now-from-25/

by schappim • 7 years ago

187 74 7 years ago

StavrosK9• 7 years ago

This looks delectable for the eMMC storage alone. I wish there were a Raspberry Pi model that came with it... I'm tired of SD cards causing problems and eating my data or (more frequently) causing the Pi not to boot.

I also wish Raspbian had an option to mount all the write-heavy directories (logs, etc) on tmpfs, so they wouldn't wear the card out so quickly.

dividuum3• 7 years ago

When done properly, SD cards are reliable enough. For my digital signage product the custom OS is highly optimized around avoiding IO as much as possible. There are thousands of devices, some running more than 4 years now, without any SD related problems.

I also really like the fact that the Pi is pretty much stateless. So switch SD cards and you can be mostly sure everything still works. If storage is bundled, that's a lot more difficult.

skl_2• 7 years ago

Out of interest, how did you approach disk encryption? That would be my concern with removable storage. The other thing I'm keeping an eye on is Arm's LittleFS for storage longevity.

StavrosK9• 7 years ago

Sure, but I don't have the time to highly optimize a custom OS just to put up an MQTT server in my parents' house. I want to do the work once and have it Just Work after that.

sgt• 7 years ago

For most use cases, SD cards on Raspberry Pi's are not reliable enough.

I realize you may be successful in running signage devices, but most people want to simply be able to run common class 10 card (e.g. from Verbatim, Kingston, Sandisk), using a standard OS setup and leave the Pi running without having it corrupting your files. This simply isn't possible, in my experience. Also look at the OpenHAB forums as a reference.

The more regular disk activity, the worse it gets.

We went this route in our office and every 3-6 months we had corruption on each of many dozen Pi's. Once we switched to using USB drives (spinning or SSD) the issues were sorted out.

blihp• 7 years ago

Well it's just Linux so you definitely can and that's what I do. As a result I've been running my pi 2 on the same card for nearly 4 years now with no issues. But if your point is that it should do it out of the box for you, I agree it shouldn't require manual setup.

StavrosK9• 7 years ago

Yeah, that's what I meant. It's not hard to do, but it's one more thing and it would be nice if it were done automatically.

stefan_• 7 years ago

Of course, IO performance remains terrible.

forinti• 7 years ago

You can (should) disable logging on raspbian:

  sudo systemctl stop rsyslog

  sudo systemctl disable rsyslog

It also makes sense to create a temporary directory in memory, if you don't need much space.

StavrosK9• 7 years ago

That's not a great solution because I do need logging sometimes, especially to see what processes are doing, I just don't need it persisted.

naikrovek2• 7 years ago

I believe recent versions of Raspbian (at least the ones available on raspberrypi.org) mount all of /var as tmpfs. That's a RAM filesystem.

StavrosK9• 7 years ago

That's great! I'll need to rebuild my Raspberry Pi if that's the case, maybe make everything run in some repeatable way so I can reprovision quickly if I need to, thank you.

arthurfm• 7 years ago

DietPi does too...

https://dietpi.com/phpbb/viewtopic.php?f=8&t=5&start=20#p68

_ea1k3• 7 years ago

I've heard that these are better: https://www.digikey.com/product-detail/en/atp-electronics-in...

I haven't tried them myself, though.

StavrosK9• 7 years ago

Oof, pretty pricy, huh.

EDIT: I see in other comments that they're worth it, so they're a great option for when I need reliability at a premium, thanks!

thinkmassive4• 7 years ago

Oh yeah, I recommended these in the past and just mentioned them again in another comment on this thread :)

4GB is enough for most Pi projects, and <$20 premium is worth never needing to worry about SD reliability to me. My understanding is they use multi-level cells, which are far less expensive than true industrial grade single level cells, but they only write a single value to each cell, increasing the reliability significantly.

Fnoord• 7 years ago

Industrial grade AMLC, for example from this reseller and brand, haven't let me down yet. Other HN users have a similar experience. The downside is the price. Delivery was one day from Springfield to The Netherlands but had to pay duties. Which is like a total opposite of China: bad quality, cheap, slow delivery, but no duties

leetbulb• 7 years ago

Check out the NanoPI[0]. I've had really good luck with it.

Also, the Zymbit[1] works nicely with its eMMC.

0: http://nanopi.org/ 1: https://www.zymbit.com/zymkey/

StavrosK9• 7 years ago

That's interesting, thanks! Although, aren't AllWinner the devil? I think I recall someone saying that.

thinkmassive4• 7 years ago

I had problems with Samsung and SanDisk cards, which worked fine in a GoPro, and troubleshooting the weird Pi symptoms was aggravating. So I tried aMLC cards from ATP and have had zero issues. They cost significantly more (~$20/ea for 4GB @ qty 10 from Digikey w/shipping) but it’s worth avoiding the hassle to me.

Obviously 4GB is not a lot, so I use tmpfs and USB storage as appropriate.

glenneroo2• 7 years ago

According to SanDisk support[0] they only support the High Endurance line of SD Cards[1] for Raspberry Pi.

[0] https://www.raspberrypi.org/forums/viewtopic.php?p=1257129 (2nd to last comment in the thread)

[1] https://www.amazon.de/gp/product/B00V5Q1K3O/

jftuga• 7 years ago

Check out: https://github.com/azlux/log2ram

Explanations: The script creates a /var/log mount point in RAM. So any writing of the log to the /var/log folder will not actually be written to disk (in this case to the sd card for a raspberry card) but directly to RAM. By default, every hour, the CRON will launch a synchronization of the RAM to the folder located on the physical disk. The script will also make this copy of RAM to disk in case of machine shutdown (but cannot do it in case of power failure). This way you avoid excessive writing on the SD card.

StavrosK9• 7 years ago

This is the best of both worlds, thanks!

dividuum3• 7 years ago

Previously the only official way to get a 16GB variant of the Compute Module was to use the NEC edition[1][2]. Looks like that got a lot easier now.

[1] https://www.nec-display-solutions.com/p/eeme/en/products/acc...

[2] From what I understand it still has all codecs unlocked by default which you'd have to do manually with the new CM3+.

Sir_Substance3• 7 years ago

I remain surprised that there don't seem to be any of the shelf "blade centers" for raspberry pi compute modules. It seems like they're the ideal hobbyist and small business expandable computing resource.

Someone did make this at one point: https://hackaday.com/2016/01/25/raspberry-pi-zero-cluster-pa...

But it was never commercialized as far as I know.

timthorn• 7 years ago

You mean the BitScope Cluster? http://cluster.bitscope.com/solutions

_ea1k3• 7 years ago

Those use the regular raspberry pi rather than the compute module, though, don't they?

_ea1k3• 7 years ago

The board that you are pointing to is a cluster of Pi Zeros.

I've sometimes had the same question, and have also wondered what industrial applications the compute module is being used for?

siffland• 7 years ago

I use the sopine cluster modules and a clusterboard for my docker swarm. The sopine modules have a quad core and 2GB of ram and a sd card slot. It is a cheaper way of having a docker swarm (you could run kubernetes, but that is overkill).

As for the Raspberry pi module, it is the same price as the sopine module and half the RAM. One could argue the pi is better supported, but the sopine modules support armbian (and are actually in stock).

So is it worth it, well not right now. If you buy the module and the base board it is just cheaper and better to by a pi 3+. I saw a pi compute module backplace to hold 5 (i think it was 5) modules for like $250 (a pine64 clusterboard for 7 modules and a built in Gb switch is $100).

There are probably uses for it, maybe custom embedded devices, but i am not 100% convinced. I was a lot more excited about the Raspberry Pi 3+ Model A. That is nice for the price, but even then nano pi's have comperable devices for simliar cost (and are actually in stock).

I still love Raspberry Pi's though and can't wait until the 4 comes out. But as my Rock54 screams with a quad core and 4GB of emmory and usb3 for $45, i am questioning what a raspberry Pi 4 could bring to the table for the same price (M.2, 8GB of ram, etc...).

bradfa3• 7 years ago

miniNodes makes a 5 socket Raspberry Pi compute module "cluster" board which seems decent:

https://www.mininodes.com/product/5-node-raspberry-pi-3-com-...

Sir_Substance3• 7 years ago

Hey, neat. Looks like they're still in pre-order mode, but I'll def keep an eye on them.

detaro• 7 years ago

Outside of hobby purposes of "I made a cluster, that's cool!", I'm not sure why many people would want such a thing compared to bigger machines.

akhilcacharya• 7 years ago

Right, I'm sure even using the AWS ARM instances would be faster/cheaper for its performance.

technofiend• 7 years ago

There's the cluster hat which supports 4 Pi Zeros on a Pi Hat. Good for hobbyist tinkering anyway.

https://clusterhat.com/

carlsborg• 7 years ago

Doesn’t seem to have 802.11 WiFi on board. Would have been nice for diy iot projects on the raspberry ecosystem.

adamfeldman• 7 years ago

Not quite DIY prices, but companies like Balena make RPi Compute Module carrier boards w/ WiFi https://www.balena.io/fin

24gttghh• 7 years ago

Well, at least it wont shit the bed (i.e. SD card corruption) on a power fluctuation?

Is there something with similar hardware? Basically something with built-in, actual SSD flash.

I love the size and low-power use of the RPi 3+, but I hate having it's SD card die on me...

mark_l_watson• 7 years ago

Thanks to other commenters for the Balena and miniNodes links. I would be interested in something neatly packaged so it would look nice on my desk that had about a dozen computer boards with local networking set up.

matthewmacleod2• 7 years ago

The other option for that use case is the Pi Zero W, which is probably a bit friendlier for most use-cases. It has the older BCM2835 from the Pi 1 (but at 1GHz) – it's quite a bit cheaper, though does require the additional SD card.

lovelearning2• 7 years ago

"CM3+ will be available until at least January 2026" - That's an impressive commitment. I'm pleasantly surprised to see them stick their necks out that long into the tech future.

pdpi2• 7 years ago

It’s not consumer electronics, they’re targeting industrial applications. Is it that long a timeframe in that world?

lovelearning2• 7 years ago

7 years availability seemed impressive to me, but I don't know, may be it's common in industrial embedded.

bradfa3• 7 years ago

It's not horrible but it's not remarkable either. 8 years is a decent but it's nothing compared to other SoM (system on module) vendors like Toradex. Toradex generally offer 12+ year commitment on their SoMs.

Consider that if you start a design now using a SoM that you probably won't get to market for at least 1 year. Then in the industrial/commercial space it'll take at least another year for your sales to ramp up. If you started today designing with a CM3+ then you'd get 6 more years of sales out of the product after sales ramp, but since the above timeline is going to hold for your replacement of the current product, you're going to have to start engineering on the replacement 6 years from now. For some industries this will sound amazing, for others it'll sound like a deal breaker.

If you look at SoC (system on chip, the processor) vendors, generally they're offering 20+ years of sales from release for SoC which target the industrial/commercial embedded markets. Vendors like TI or NXP don't generally end of life their silicon for a very very long time.

eurg• 7 years ago

If you need 15/20 years, you get a separate contract. 7 years as a baseline is not too bad, for that kind of device, but likely not sufficient on its own. Automotive test-beds etc. would require longer timeframes.

flyinghamster• 7 years ago

The other thing that impresses me is that the modules have remained electrically compatible, so (at least in theory) you could slot out a CM1 for a CM3+ and still expect it to work.

bpye• 7 years ago

Perhaps, the CM3 (and I assume CM3+) have significantly higher power requirements.

dom96• 7 years ago

Slightly off-topic but does anyone known any good similar modules with support for LVDS and/or eDP displays (15"+ ideally)?

I've been wanting to assemble a sort of tablet device but I am having a really hard time finding a display/compute combo that will work with any confidence. I would ideally like to avoid having to get a separate A/D board.

tyingq• 7 years ago

The OrangePi Win supports LVDS: http://www.orangepi.org/OrangePiWin_WinPlus/

Though, documentation is likely sparse.

fest• 7 years ago

I've done this on Olimex A20 boards (random laptop LCD had LVDS, A20 had LVDS output).

Recently I've used NanoPC-T4's eDP output. Unfortunately, their eDP pinout does not match VESA standard pinout, so I had to make an adapter board.

matthewmacleod2• 7 years ago

The UP board has eDP support. It's a fair bit more expensive, but it does have the benefit of an Intel chip: https://up-board.org/up/specifications/

ourcat• 7 years ago

Very tempting.

I recently saw this project for processing 3d 'vr180' stereoscopic vision with a Pi Compute module, called StereoPi. http://stereopi.com/

coleifer• 7 years ago

Excuse the ignorance, but how does one use it? What would be some applications for this?

shifto• 7 years ago

I saw an example of someone making a gameboy-like pcb on which you could plug in this module as a brain.

https://hackaday.com/2017/11/17/raspberry-pi-compute-module-...

thinkmassive4• 7 years ago

It would be really cool if someone created an updated RaSCSI for the Compute Module https://github.com/fran-cap/RASCSI-68kmlaver

New Raspberry Pi Compute Module 3+

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