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Raspberry Pi Compute Module

raspberrypi.org

71–80 of 116 posts

Re: Raspberry Pi Compute Module

#71
post #68

Can this be plugged into a DDR2 DIMM and allow host Pi communication (with an appropriate kernel driver)?

The article says: > But don’t go plugging the Compute Module into your laptop – the pins assignments aren’t even remotely the same! So the answer is "no."

Sounds like doing this will let out the magic smoke in a hurry.

Do you think they've fused it so it doesn't short out and trash any board you put it into by mistake?

Re: Raspberry Pi Compute Module

#73
Can other computer-on-modules in a SODIMM package be used in the Compute Module IO Board they are developing?

I've searched online, and I think the boards that the SODIMM modules are plugged-in to are called "base-boards" or "carrier-boards". In general, are these kinds of boards generic in nature, so that you can mix-and-match modules with different carrier-boards, as long as they all use the SODIMM package?

Re: Raspberry Pi Compute Module

#74
post #49

Looks really cool but I'm slightly disappointed to see that when buying these Compute Modules in bulk they still each cost about the same as a single full Raspberry Pi (Version A). The Compute Modules do have 4gb of built in flash that the Version A doesn't have though.

It looks like the module plus the I/O board costs $30 in large quantities. So aren't you really getting pretty much the same deal? I'm sure the modules alone will be cheaper.

No, from the article it appears the module by itself will be $30. With the I/O board the price will be higher:

"...the Compute Module will be available to buy separately, with a unit cost of around $30 in batches of 100"

Re: Raspberry Pi Compute Module

#75

So for many distributed computations in my field (pretty much anything that isn't embarrassingly parallel [0]), the limiting factor is often network communication -- how quickly nodes can send messages to each other. Even as just a toy, putting an affordable arm chip with a serious interconnect would be a really big deal. This is a great step closer. [0] http://en.wikipedia.org/wiki/Embarrassingly_parallel

The Calxeda ECX-1000/2000 would have been ideal for you then - 4x10GbE interconnects with a quad core A9/A15. Shame they went under - but there are alternatives from Marvell, Applied Micro and others. Look for ARM server chipsets and you'll usually find a good fabric attached.

You will also find a large price tag. And probably inability to actually buy one alas.

Re: Raspberry Pi Compute Module

#76

It's about time they put some FLASH on-board. SD card has proven time and time again an unreliable medium. You never know if the device would boot up after a "dirty shutdown"

My understanding is eMMC flash memory is an SD card soldered onto a board, so if anything that problem could be worse without the advantage of a removable card

You are correct. I jumped the gun. This in fact will probably be worse that having a removable SD card.

Re: Raspberry Pi Compute Module

#77

Earlier quoted context omitted.

The Calxeda ECX-1000/2000 would have been ideal for you then - 4x10GbE interconnects with a quad core A9/A15. Shame they went under - but there are alternatives from Marvell, Applied Micro and others. Look for ARM server chipsets and you'll usually find a good fabric attached.

You will also find a large price tag. And probably inability to actually buy one alas.

You can get the Mirabox based on the Marvell Armada 370 for about £150, one-off. Includes dual 1GbE.

Eg http://www.newit.co.uk/shop/All-MiraBox/MiraBox

Re: Raspberry Pi Compute Module

#78
post #65

The price is getting better but it's still in the "I used my pi for the project" vs the "I used a pi..." range. Things get interesting when a general purpose Linux computer reaches disposable pricing where you just pull a new one from the bin for each project. This feels like about $20usd or less to me.

So what happens to all that e-waste when you throw out an old computer board because you don't feel like wiping it?

Patiently waiting in a trash field for a future entrepreneur genius who would devise a way to extract on the cheap anything and everything useful from it.

Re: Raspberry Pi Compute Module

#79
post #65

The price is getting better but it's still in the "I used my pi for the project" vs the "I used a pi..." range. Things get interesting when a general purpose Linux computer reaches disposable pricing where you just pull a new one from the bin for each project. This feels like about $20usd or less to me.

So what happens to all that e-waste when you throw out an old computer board because you don't feel like wiping it?

Well with this system on memory footprint, if my application doesn't need Ethernet I won't add one to the board, and if I don't add one to the board then the jack and chip won't be wasted or e-wasted.

Re: Raspberry Pi Compute Module

#80
post #68

Earlier quoted context omitted.

The article says: > But don’t go plugging the Compute Module into your laptop – the pins assignments aren’t even remotely the same! So the answer is "no."

Sounds like doing this will let out the magic smoke in a hurry. Do you think they've fused it so it doesn't short out and trash any board you put it into by mistake?

Seems unlikely. Fuses, MOVs, and clamp diodes cause signal integrity issues (especially at 3.3V and under). And, for 200 lines, the cost might be impressive.

That said, if the Pi foundation can arrange for all the I/O to come out of reset in a hi-Z state, then there's a chance they could arrange the rest of the pins to avoid damage.

But would it be worth the effort? Given how hard it is to access most sodimm sockets, mistakes seem rather unlikely.

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