raspi is not the ARM I’m looking for

I got a raspberry pi a couple years ago as a christmas present from my brother-in-law. I like the idea. A cheap computer with roughly the same horsepower of my workstations of yesteryear, in a power-sipping small form factor. I want to believe, but the experience is disappointing.

First disappointment was that the accouterments for the pi (power supply, SD card, functional case, wifi adapter) cost as much as the base unit. The 1541 disk drive also cost more than a c64, so this isn’t a horrible shock, but the $40 pi price is not all-inclusive.

I christened my pi “bunnypi,” and originally had it mounted on the back of a dedicated monitor with a LaRu bunny sticker on it. My original plan was to introduce my son to old-school DOS games via DOSBox on it. This was marginally successful, since DOSBox runs only at roughly the 286-12 level, with noticeable performance glitches. This hasn’t stopped my son from playing with “the guys” in Ultima VI, or matching words in reader rabbit, but an actual 386 is more performant. ScummVM seems to run reasonably well with older titles, but is not frequently updated from upstream, so some of my favorite games remain unsupported on the pi.

Bunnypi not terribly reliable. It seems prone to overheating. A few times a year the raspbian updater seems to corrupt its own bootloader, leaving me with having to manually perform firmware and loader fixups. Part of the unreliability is just cheap hardware — the “official” power supply I received mine seems to have lost capacity over time, and plugging in the WiFi adapter caused the system to reset. It would hang at boot if the WiFi was left plugged in. I replaced the power supply with a beefier unit from my now-broken tablet, (which can source extra current needed for charging,) and it seems to be working better, although I’m still seeing periodic USB disconnect / reconnect cycles. As for the linux updates / upgrades, screwing up the boot process somehow seems par for the linux distro course. (Take distro of your choice, find the earliest version that will install on your target hardware or VM, and walk it through updates / upgrades to the latest version, and see if it makes it…)

The on-board audio of bunnypi is noisy PWM, limiting its utility for music playing. The noise is signal-correlated, so adding some noise-shaped dither might be able to help, but setting up the audio output chain is quite fiddly. Add-on boards with discrete DACs are available, or maybe a cheap $5 USB adapter would be good enough?

Bunnypi can drive my 1080 TV over HDMI, and the kids do love the screensavers, but the accelerated graphics support seems nonexistent. A little reading indicates the graphics acceleration supported on the pi is OpenGL ES, not standard OpenGL. Youtube videos of ES demos on the pi show it is capable of high-framerate graphics, but apparently doing a translation of OpenGL to OpenGL ES to get standard X screensavers either hasn’t been done yet, or is technically prohibitive. (Impossible? This is open source, right?)

USB is the only I/O available beyond GPIO and SD, so I don’t honestly know how people develop for this unless there is a cross-compile environment, emulator, or binary-compatible bigger brother that I’m not aware of. (Do people really put in giant SD cards to do raspi development? Or use USB hard-drives?)

The web browser is awkwardly slow. I installed a supposedly optimized webkit-based browser, but it wasn’t noticeably faster. And of course no flash or HTML5 video support, so no youtube.

The core use of bunnypi remains a dedicated screensaver generator.

Where are the grown-up ARM systems? Something with real I/O (PCIe, SATA, 100M+ ethernet) and ECC memory?

One thought on “raspi is not the ARM I’m looking for”

  1. updated to stretch, and pi is still unstable, although the hybrid graphics acceleration is a LOT faster at 3d. after I disabled graphics head, the system chugs along merrily, pointing to graphics engine as the problem. why a peripheral can wedge the entire system points to a brittle architecture, but I digress… stability sans graphics does make the system more suitable for light-duty non-critical work.

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