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Raspberry PI 2 or Compute module

balearicdynamics

Unfortunately this is not a tutorial nor a specific question; I'd like start a discussion to all the users that are interested and those that - hopefully - has a minimum of experience on the use of the Raspberry PI compute module.

 

My starting point, as far as I know and read here and there in the documentation is a bit confusing and can be synthesised as follows:

 

  • The compute module is the "core" of a raspberry PI, probably equivalent to a B+ 512 Mb Ram and in the DIMM memory size it includes ... just only the processor and the flash memory + RAM
  • There is a very good kit that can host the computer module exposing all the GPIO, interfaces, camera, display etc. But the resulting price, without the ethernet connection and a couple of other secondary components, is about the double of a Raspberry PI2 (that is the next PI version, faster, more memory etc.
  • Any customer can develop its own I/O board saving money, but the Computer module alone is not sold. So the only possibility is to buy the entire kit
  • It is presented like the "pro" version of the Raspberry PI for industrial applications and more sophisticated embedded developments, but has less things and my perception is that is less flexible.
  • In some documents it is explained that it can be designed to support pre-built cstomer programs developed under Linux all flashed on the module, but in some other documentation are mentioned pay-per-license operating systems.

 

These are only some of the incongruences that it seems emerging from the first view comparison. In a project I am working with I though about the computer module as an alternative to the PI but to be honest I have a lot of perplexity.

 

I hope that someone explain me that I am totally wrong, I have not understood the basic principle and tell me what is the reason to make this choice creating a custom system running a bunch of specific applications. And also what can be the reason of a so high (double) price that makes this device IMHO absolutely not competitive respect the Raspberry PI 2.

 

Enrico

Parents

  • No, you have summed up the advantages/disadvantages pretty well although I'm pretty sure you can buy only the compute modules if you want to.

     

    I am assuming that at some time in the future a Pi 2 core compute module will become available, the only question is will it be soon enough to help you ?

    Unfortunately since the Rapsberry Pi Foundation has become a bastion of secrecy for no apparent reason (paranoia ?) it is impossible to say.

     

    @Clem

     

    A lot of clusters still use Ethernet (although it is more likely to be 10 GB/s and of course they also require routers) and a FPGA would be required to make a bus interface between

    the Pi modules increasing the size, power, complexity and cost by a considerable amount while providing (much) less than half of the compute power per module.

  • in reply to gdstew

    Gary,

     

    usually the dev kit - is the producer really want to sell the product - is always distributed in the meantime as the product itself, as an alternative to simplify the engineers in their own projects. This occur with all I saw with Texas, Panasonic, NXP, Atmel and many more. Now are months that this B+ model is on the market, but there is not announcement at all of the product to be bought by itself.

     

    Then also this super-secrecy and, sure, paranoid behaviour I think it is simply damaging the market itself. PI clones exists anyway, the conceptual architecture of this board is not so complex to be kept in absolute great secret and, despite I love it very much it is anyway in the average of many other devices. At this point, to have a reliable linux working on a well assessed machine in an industrial or anyway custom application it is the worth I spend few more money (but very few) and buy a Gizmo2 from gizmosphere, with more potential, open-hardware and really customisable in a lot of ways...

     

    Enrico

  • in reply to balearicdynamics

    I can't see any point in the RPI compute module because:

     

    1) It's so obviously not the core business (as evidenced by the lack of  RPI2 version).

    2) The RPI people are not a B2B supplier (so they don't understand about providing information, proper support etc).

    3) The closed nature of the RPi and its processor mean that you can't just make the things yourself if you have to or if the numbers get big.

    4) There isn't enough on the Compute module so you end up with an expensive interface to a support board, which itself may be pricey.

    5) You still don't get proper Ethernet

    6) You don't, for all that you have the huge connector, get PCIe or any other high speed bus

    7) You can get all this stuff by other cost competitive routes without the supply and support issues.

     

    So - use Pis if they suit (as they are) and you don't mind if you can't get them next year (and you don't mind having no idea at all what the development roadmap is)

     

    MK

Reply
  • in reply to balearicdynamics

    I can't see any point in the RPI compute module because:

     

    1) It's so obviously not the core business (as evidenced by the lack of  RPI2 version).

    2) The RPI people are not a B2B supplier (so they don't understand about providing information, proper support etc).

    3) The closed nature of the RPi and its processor mean that you can't just make the things yourself if you have to or if the numbers get big.

    4) There isn't enough on the Compute module so you end up with an expensive interface to a support board, which itself may be pricey.

    5) You still don't get proper Ethernet

    6) You don't, for all that you have the huge connector, get PCIe or any other high speed bus

    7) You can get all this stuff by other cost competitive routes without the supply and support issues.

     

    So - use Pis if they suit (as they are) and you don't mind if you can't get them next year (and you don't mind having no idea at all what the development roadmap is)

     

    MK

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