Finding unpopulated pads on a circuit board is often a sign that the device in question has some untapped potential. These blank spots on the board could be left over from features or capabilities that were deleted from the design, or perhaps even represent an optional upgrade that wasn’t installed on this particular specimen. So we certainly understand why [d0rk] was fascinated by the empty SO-DIMM footprint he recently found on a laptop’s motherboard.
The budget Celeron machine shipped with 4 GB of RAM installed in its single socket, a situation [d0rk] hoped he could improve upon with the addition of a second module. But could it really be as simple as pulling the socket from a dead motherboard and soldering it into place? Would other components need to be added to the board? Could the BIOS cope with the unexpected upgrade? There was only one way to find out…
At first, it seemed like the patient didn’t survive the operation. But a close look uncovered that the power button had actually gotten damaged somewhere along the line. Once [d0rk] fixed that the machine started up, but unfortunately the operating system didn’t see the extra RAM module. Even after upgrading the BIOS, the computer remained oblivious to the additional memory.
When he went back in to inspect his solder work for shorts or bad joints, disaster struck. For reasons that aren’t immediately clear, the computer no longer starts. Even after pulling the transplanted SO-DIMM slot off the board entirely, [d0rk] says it won’t make it through the self-test. Obviously a disappointing conclusion, but we respect the effort he put into the attempt.
It’s that time of year again, with the holidays fast approaching friends and family will be hounding you about what trinkets and shiny baubles they can pretend to surprise you with. Unfortunately there’s no person harder to shop for than the maker or hacker: if we want it, we’ve probably already built the thing. Or at least gotten it out of somebody else’s trash.
But if they absolutely, positively, simply have to buy you something that’s commercially made, then you could do worse than pointing them to this very slick Raspberry Pi cluster backplane from [miniNodes]. With the ability to support up to five of the often overlooked Pi Compute Modules, this little device will let you bring a punchy little ARM cluster online without having to build something from scratch.
The Compute Module is perfectly suited for clustering applications like this due to its much smaller size compared to the full-size Raspberry Pi, but we don’t see it get used that often because it needs to be jacked into an appropriate SODIMM connector. This makes it effectively useless for prototyping and quickly thrown together hacks (I.E. everything most people use the Pi for), and really only suitable for finished products and industrial applications. It’s really the line in the sand between playing around with the Pi and putting it to real work.
[miniNodes] calls their handy little device the Carrier Board, and beyond the obvious five SODIMM slots for the Pis to live in, there’s also an integrated gigabit switch with an uplink port to get them all connected to the network. The board powers all of the nodes through a single barrel connector on the side opposite the Ethernet jack, leaving behind the masses of spider’s web of USB cables we usually see with Pi clusters.
The board doesn’t come cheap at $259 USD, plus the five Pi Compute Modules which will set you back another $150. But for the ticket price you’ll have a 20 core ARM cluster with 5 GB of RAM and 20 GB of flash storage in a 200 x 100 millimeter (8 x 4 inch) footprint, with an energy consumption of under 20 watts when running at wide open throttle. This could be an excellent choice for mobile applications, or if you just want to experiment with parallel processing on a desktop-sized device.