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Raspberry Pi Alternatives

There is a certain attraction in saying a particular device uses a Raspberry Pi – even people who don't use them have heard of them. The Raspberry Pi 3B+ is now the default Raspberry Pi but it's not a perfect solution for every purpose. Sometimes it's too big, sometimes it's too slow.

This page details some alternatives but does not attempt to be exhaustive. There are many many SBCs but only a few really stand out to me as being possibly worth buying for the right application.

Remember that the prices mentioned below are not the full cost. Power supplies, microSD and eMMC cards are not included, although some of the boards below have eMMC onboard. Shipping is not included except where noted.

Acronym explanations (SBC, SoC, etc) can be found on the Computer Acronyms page.

Default Raspberry Pi

Raspberry Pi 3 Model B+ Main Features

The go-to single board computer with the broadest user base, best support, the greatest number of operating systems... the list goes on.

The Raspbian OS is 32 bit, but the CPU is 64 bit. Because of the small amount of RAM it's unlikely to be economical to run a 64 bit OS. (This is seldom an issue.)

SoC: Broadcom BCM2837B0.
CPU: 4x Cortex-A53 @ 1.4 GHz; 64 bit.
FPU: VFPv4 + NEON.
GPU: 1080p30 H.264/MPEG-4 AVC.
RAM: 1 GB LPDDR2 SDRAM shared with GPU.
Storage: MicroSD up to 32 MB.
GPIO: RPI-standard 40-pin header.
USB: 4x USB 2.0, shared via onboard 5 port hub.
Network: 10/100/1000 Mbit/s Ethernet (real speed max 300 Mbit/s), 802.11b/g/n/ac dual band 2.4/5 GHz wireless, Bluetooth 4.2 LS BLE.
Other: No RTC, and using a screen plugged onto the GPIO pins means no way of plugging in an RTC.
Power: 5 V via USB Micro-B.
Size: 85.6 mm x 56.5 mm x 17 mm.
Weight: 45 grams.
Price: US$35. NZ$63.25 from PB Tech (~US$42).

NEW (25 June 2019):

Raspberry Pi 4 Model B Main Features

The just-released upgrade of the go-to single board computer with the broadest user base, best support, the greatest number of operating systems... the list goes on.

Now with a quad-core ARM Cortex-A72, up to 4 GB RAM and USB 3.0.

With those significant improvements this release has addressed several of the main problems with the RPi3B+ and earlier models. Specifically, too little processing power, too little RAM and no USB 3.0. The arrival of 4K video of course is also appreciated.

The Ethernet port has swapped which side it's on, and the HDMI socket is now two micro-HDMI sockets. Those changes along with the slightly increased size all means it won't fit in existing cases.

Quite apart from most shops around the world selling out of their limited stock very quickly, there are a few issues with Raspbian Buster, the latest version of the operating system. Things don't run completely smoothly (such as 4K video playback). Idle temperatures up to 67 °C have been reported, along with thermal throttling reducing performance to less than a Raspberry Pi 3B (eg, 41 seconds for a prime number calculating task instead of 10-11 s).

Conclusion: Heatsink needed, and the default case really isn't such a good idea.

SoC: Broadcom BCM2711, 28 nm process (the same as the four year old XU4).
CPU: 4x Cortex-A72 @ 1.5 GHz; 64 bit. (Can be overclocked up to 2 GHz.)
FPU: VFPv4 + NEON.
GPU: VideoCore VI at 500 MHz providing dual 4K @ 30 fps or single 4K @ 60 fps.
RAM: 1 GB, 2 GB or 4 GB, 2400 MHz LPDDR4.
Storage: MicroSD (unknown maximum size), "doubled the speed of the SD card" from 3B+.
GPIO: RPI-standard 40-pin header.
USB: 2x USB 3.0, 2x USB 2.0.
Network: 10/100/1000 Mbit/s Ethernet (genuine gigabit now), 802.11b/g/n/ac dual band 2.4/5 GHz wireless, Bluetooth 5.0.
Other: 2x micro-HDMI ports, each supporting 4K display. MIPI CSI and DSI.
Power: 5 V via USB-C (15 W). Power over Ethernet.
Size: 88 mm x 58 mm x 19.5 mm.
Weight: 46 grams.
Price: 1 GB US$35/AU$53.64. 2 GB US$45/AU$69.09. 4 GB US$55/AU$84.55.

15 W USB-C power supply AU$13.59. Micro-HDMI to HDMI cable AU$6.32. Shipping to NZ AU$11.15.

Total AU$115.61/NZ$124.42 incl shipping (4 GB, power supply, micro-HDMI cable, NO case). Heatsink and microSD card extra. (AU prices without tax.)

Smaller alternatives

These boards are smaller than a RPi 3B+ but mostly do not offer the same functionality.

Arduino Nano (clone) Main Features

Very small and powerful enough to do some very impressive stuff. Very easy to use if you have the driver for the CH340 USB controller chip, which is used to reduce the price compared to the original.

In NZ the original Arduino Nano costs up to 17 times as much as the clone.

This is not a direct competitor to the RPi 3B+ because it's a microcontroller not a microcomputer, meaning it doesn't have an operating system but has a single program loaded at a time. However, it is actually more suitable than RPi for many purposes.

MCU: ATmega328 @ 16 MHz.
RAM: 32 KB program memory (of which 2 KB is the boot loader), 2 KB RAM.
Storage: Can be expanded to use microSD cards.
GPIO: 30 pins (all 5 V), which can be plugged into a solderless breadboard. 8 analogue pins (10 bit sampling), 22 digital pins (6 of which are PWM).
USB: 1x USB mini-B used for power and serial communication.
Network: Serial connection via USB or I/O pins.
Other: No onboard RTC, but lots of inexensive expansion modules and sensors are available (including various RTCs).
Power: 5 V via USB mini-B, or pin 27, or 6-20 V input on pin 30; 19 mA draw.
Size: 45 mm x 18 mm.
Weight: 7 grams.
Price: US$2.45 each, or as little as US$2.20 each if buying 10.

Arduino Mega Pro (clone) Main Features

A little over twice the size of the Arduino Nano (but still much smaller than a RPi) and with more storage and RAM than the Nano. Has the CH340 USB controller chip.

In NZ a full size "Arduino™-Compatible" Mega costs 7 times as much as the Mini Mega clone, while a genuine Arduino Mega costs 10.5 times as much.

MCU: ATmega2560 @ 16 MHz.
RAM: 256 KB program memory (of which 8 KB is the boot loader), 8 KB RAM.
Storage: Can be expanded to use microSD cards.
GPIO: 70 pins (all 5 V), can be plugged into a solderless breadboard; 54 digital pins (of which 15 are PWM), 16 analogue pins.
USB: 1x USB micro-B used for power and serial communication.
Network: Serial connection via USB or I/O pins.
Other: No onboard RTC, but lots of inexensive expansion modules and sensors are available (including various RTCs).
Power: 5 V via USB micro-B.
Size: 55 mm x 38 mm.
Weight: 17 grams.
Price: From about US$6.60 or NZ$10.50 each.

Even smaller than an Arduino Nano

PICAXE. Available in 8 pin up to 40 pin DIP (dual in-line package) and SMD (surface mount device). All current PICAXEs have at least 2KB memory for programs. Default clock speed is 4 MHz or 8 MHz but can be manually set to run faster.

Programmed in BASIC over a serial connection. The BASIC is interpreted by a bootstrap program in the EEPROM, so the speed is slower than Arduino (perhaps 1,000 BASIC instructions per second).

Less expensive and much faster

Even less expensive than the Arduino Nano clone but faster and with more memory is the "STM32F103C8T6 Minimum System" (aka "Blue Pill"), for those wanting to get into STM32. It's less than NZ$3.

  • 32 bit Cortex-M3 microcontroller running at 72 MHz.
  • 64 KB flash memory, 20 KB SRAM (allows lots of strings to be stored in RAM!).
  • 2.0-3.6 V power and I/O.
  • About half the I/O pins are 5 V tolerant.
  • 12 bit A/D converters, 0-3.6 V.
  • Size 53 mm x 23 mm, or 58 mm x 23 mm including header pins on the end; it's a little larger than an Arduino Nano clone. Part of the reason for this is the pin numbers are printed along the outside edges and some tracks on the printed circuit board run along the outside of the pin holes.
  • Micro USB connector.
  • Will possibly need a resistor modification to get USB working.
  • First time used you might like to burn a USB bootloader.
    • This uses 20 KB, thus reducing the available flash memory to 44 KB. It's possible to program it without the USB bootloader – by using the same method each time as used in the two options below to install the bootloader – but that's not as convenient.
    • An Arduino Nano clone can act as a USB to serial adapter. Because the Nano is acting as a relay, the serial communication pins are not crossed over; connect TX pin to TX, RX pin to RX. RX1 on Blue Pill is 5 V tolerant but RX2 is not, so it will need a voltage divider to drop 5 V to 3.3 V; 1 kΩ and 2 kΩ resistors will do nicely. The TX pin transmits from the Blue Pill and 3.3 V is HIGH so it doesn't need a voltage divider. The Reset pin on the Nano also needs to be connected to ground, or upload a sketch to it that sets pins 0 and 1 to INPUT and does nothing else.
    • Or buy a USB to TTL serial adapter with a CP2102 chip, which will likely need a driver installed on your computer to use (and the driver will not work on Mac OS 10.8 or earlier). Remember to set the output voltage of the adapter to 3.3 V.
  • After installing some STM32 libraries it can be programmed with the Arduino IDE (with some code differences).

Great Scott has an excellent video comparing the Blue Pill with the Arduino Nano, and explains how to get 36 MHz PWM.

The Blue Pill is a little less convenient than an Arduino Nano clone, so not the best for beginners to learn on, but there is a STM32F103RCBT6 version (aka "Maple Mini clone") at about twice the price which is supposed to be plug and play (other than not all of its pins being 5 V tolerant).

More power

Raspberry Pi Zero and Zero W Main Features

Much smaller than RPi 3B+ but a lot slower. However, it has the advantage that it uses the same OS.

The only difference between the Zero and Zero W is the presence of wireless connectivity in the Zero W (and the price). The Pi Zero can be a little hard to use because of its lack of connectivity, so getting the Zero W makes sense.

SoC: Broadcom BCM2835.
CPU: single-core ARM Cortex A11 @ 1.0 GHz; 32 bit.
FPU: VFPv2; NEON not supported.
GPU: 1080p30 H.264/MPEG-4 AVC.
RAM: 512 MB.
Storage: MicroSD up to 32 MB.
GPIO: 40-pin header without soldered pins.
USB: 1 Micro-USB 2.0, direct from SoC.
Network: No Ethernet. Zero W only – 802.11b/g/n single band 2.4 GHz wireless, Bluetooth 4.1 BLE.
Other: No RTC.
Power: 5 V via USB Micro-B.
Size: 65 mm x 30 mm x 5 mm.
Weight: 9 grams.
Price: US$5 Zero, US$10 Zero W. Good luck finding them for those prices.

FriendlyElec NanoPi Neo4 Main Features

Its small size, reasonably powerful CPU and GPU and some nice features make this SBC quite attractive. Having only 1 GB RAM and the lack of user base and reported lack of SoC support from Rockchip, not so much.

A heatsink is essential for doing anything serious.

There are more fully featured RX3399 boards available but this is the only RK3399 board I know of this size.

Some accessories available but no Aus plug adapter(!) and no case.

SoC: Hexa-core Rockchip RK3399 media player.
CPU: dual-core ARM Cortex-A72 @ 1.8 GHz, and quad-core ARM Cortex-A53 @ 1.4 GHz.
GPU: Mali-T860MP4, in theory 4K 10-bit H265/H264 60 fps decoding.
RAM: 1 GB DDR3-1866.
Storage: MicroSD up to 128 GB, eMMC connector.
GPIO: 40 pins at 1.27 mm (no adapter available). Some pins compatible with RPi, some provide PCIe x2.
USB: 1x USB 3.0, 1x USB 2.0, 1x USB 2.0 header, 1x USB-C used for power input also supports USB 2.0 OTG.
Network: Native Gbps Ethernet, 802.11 b/g/n, Bluetooth 4.0.
Other: RTC
Power: 5 V, 3 A via USB-C.
Size: 60 mm x 45 mm.
Weight: 30 grams without heatsink.
Price: US$50 board only. US$55 with shipping. US$94 with heatsink, power supply, 32 GB eMMC, and shipping.

Other reduced size models to note are the HC1, HC2 and MC1 listed below in the extra notes for the Odroid XU4 (of which they are a cut-down version).

Same size alternatives

These boards are the same size as the Raspberry Pi 3 model B+, but are less expensive or have more attractive features, such as more RAM or a more powerful processor.

Hardkernal Odroid XU4 Main Features

One of the fastest RPi-sized boards available which doesn't make the eyes water when you hear the price. (And in early 2019 the price was reduced by US$10. I wonder if that's because people weren't buying due to waiting for the release of the Odroid N2.)

The XU4 is now almost four years old, and is a popular board with a good user base and lots of support. That and its power make it a leading contender for a RPi replacement.

Downsides are only 2 GB RAM (which is a pity because as of June 2019 we suddenly now have several good options available with 4 GB); it's a 32 bit SoC (so running a 64 bit OS is not an option, although probably not a problem); newer alternatives have faster acceleration for crypto extensions; no Wi-Fi or Bluetooth; and GPIO pins are 1.8 V.

Input current has been seen to be as high as 3.2 A.

The two USB 3.0 sockets could be very useful for connecting fast storage and a Wi-Fi ac 2x2 adapter.

Hardkernel has an excellent range of accessories and peripherals available at mostly reasonable prices: fan and passive cooling options; cases (ports are not in the same positions as RPi); backup battery for the RTC; USB Wi-Fi adapters of various spec levels.

SoC: 32 bit Samsung Exynos5422 28 nm process (released Q2 2014). This is the same SoC used in the Samsung Galaxy S5.
CPU: Quad-core Cortex-A15 @ 2.0 GHz and quad-core Cortex-A7 @ 1.4 GHz.
FPU: NEON, VFPv4.
GPU: Mali-T628 MP6 @ 695 MHz (released in August 2012). No hardware support for 4K, so not surprising that the equipped version of HDMI doesn't support it either.
RAM: 2 GB LPDDR3, PoP stacked.
Storage: MicroSD, eMMC 5.0 connector.
GPIO: 30 pin header + 12 pin header, both 2.0 mm pitch, 1.8 V (instead of the normal 5.0 V and 3.3 V). (Use XU4 Shifter Shield to convert to RPi pinout with 3.3 V or 5.0 V, or use USB IO board for a breadboard compatible expansion.)
USB: 2x USB 3.0 ports, 1x USB 2.0 port.
Network: Gigabit Ethernet, no Wi-Fi (USB adapters available).
Other: RTC battery connector. Ports are in different locations to RPi.
Power: 5 V, 4 A via DC barrel connector (very sensible for a power-hungry low voltage board). 6 A supply needed if using an HDD/SSD.
Size: 83 mm x 58 mm x 20 mm, or 22 mm with fan heatsink.
Weight: 60 grams with fan heatsink (38 grams without heatsink); 5 grams for Wi-Fi module 5A.
Price: US$49 board only. US$65 incl shipping to NZ. US$127.02 (NZ$200) with case, 6 A power supply, RTC battery, 32 GB eMMC, eMMC reader, Wi-Fi module 5A (ac, dual band), and shipping. US$18 XU4 Shifter Shield. $13.50 USB IO board.

More notes on XU4:

  • This is arguably the most powerful RPi-sized reasonably priced SBC (until the Khadas Vim3 is eventually released) but it has comparatively poor real world performance in some tasks given its powerful CPU – apparently Ubuntu MATE (pronounced Ooboontoo MaaTey) doesn't work well with it, yet it's recommended by Odroid.
  • To get the most out of this CPU requires a custom HMP-enabled kernel (Heterogeneous Multi-Processing, also called Global Task Scheduling, GTS). It turns on all cores at the same time, instead of running just the four fast cores or the four efficient cores depending on the workload.
    • If using the XU4 mobile, HMP will, of course, result in greater battery load.
  • Boot current peaks at 3 A. This can be reduced by setting the XU4 to "boot with only the little cores and manually switch on the big cores as needed. Add maxcpus=2 (or 4) to bootargs in boot.ini". Naturally, it will take longer to boot.
  • MickMake XU4 review (with video linked from that page). He says "It is one of the more mature SBCs out there, able to run mainline Linux kernel."
  • A longer XU4 review on Mikronauts includes helpful details about what the features the XU4 has actually are (like the GPIO headers).
  • NAS versions: There are physically cut-down versions for using as a network attached storage (NAS) server.
    • US$49 HC1 (Home Cloud One) houses a 2.5" drive (5 V power supply). Without the heatsink it's about the same width as an XU4 and a little over half the length.
    • US$54 HC2 (Home Cloud Two) houses a 3.5" drive (12 V power supply).
    • They have a SATA connector instead of USB 3.0, a single USB 2.0 port, and the aluminium case also serves as the heatsink. They boot from a UHS-I compatible microSD card up to 128 GB (no eMMC connector) and are intended to run headless (no HDMI port).
    • Either will make quite a fast NAS (specs video), beating the Rock64 speed as a NAS by about 9% (but has much slower encryption).
  • Cluster version: Another cut-down version without the SATA connector, and a shorter heatsink.
    • US$48 MC1 Solo (My Cluster One, single).
    • Size: 92 mm x 42 mm x 29 mm, leading to a size estimate for the board of roughly 61 mm x 42 mm.
Pine64 Rock64 Main Features

With a power supply and shipping the 1 GB version comes to not much more than a RPi3B+ without power supply locally (PB Tech). The 4 GB version with power supply and shipping is excellent value if wanting the extra RAM and not wanting the other things the new RPi 4B comes with.

It has no Wi-Fi or Bluetooth, and lacks MIPI connecters, but these may not be serious downsides, depending on the purpose. It has much better crypto acceleration than the XU4.

Good range of peripherals available, including an aluminium waterproof box and an international power supply, which is good because it has rarer form of power socket.

Competing well for price, while featuring eMMC and USB 3.0, and offering up to 4 GB RAM, is impressive and firmly cements this SBC's position on this page.

SoC: Rockchip RK3328 media player.
CPU: 64 bit quad-core Cortex-A53 @ up to 1.5 GHz, which is the maximum spec for the chip.
FPU: NEON, VFPv3, ARMv8 Cryptography Extensions.
GPU: Mali-450 MP2, which supports 4K60p HDR (10 bit) video, and thus has HDMI 2.0.
RAM: 2 GB or 4 GB LPDDR3-1600.
Storage: MicroSD slot up to 256 GB (SDXC), eMMC connector (jumper needed to boot from it, but not included).
GPIO: 40 pin GPIO RPi compatible, 22 pin GPIO Pi-P5+ bus incl 2nd 10/100Mbps Ethernet headers.
USB: 1x USB 3.0, 2x USB 2.0 (the top one is USB OTG); all have dedicated hosts.
Network: 10/100/1000 Mbps Ethernet.
Other: IR receiver, RTC accessible over I2C and battery connector added to Rock64 Rev3 (I did wonder how it could be powered!).
Power: 5 V, 3 A via 3.5 mm x 1.35 mm DC barrel connector.
Size: 85 mm x 56 mm x 18.8 mm.
Weight:
Price: US$25 for 1 GB, US$35 for 2 GB, US$45 for 4 GB, plus US$12 flat rate shipping. Total ~NZ$80 for 1 GB or NZ$111 for 4GB, incl shipping, power supply (Aus plug), with 32 GB microSD card bought locally.

More notes on the Pine64 Rock64:

  • The Rock64 mostly has the same ports and port locations as RPi but there are a few changes, mostly for the better.
    • Power is by a barrel connector.
    • It has a single USB 3.0 port in place of two of the RPi's USB 2.0 ports.
    • It has an IR receiver.
    • There is no Wi-Fi or Bluetooth.
    • Also missing are the MIPI CSI and MIPI DSI connectors.
  • Appears to mainly be used as a media server due to its price, the USB 3.0 socket, the true gigabit Ethernet, and just maybe because the RK3328 SoC (System on Chip) was designed for TV boxes. It does rather well with multimedia, including 4K. It can be very easy to set up (video 1), or much more involved (video 2).
  • Plenty of RAM is recommended for running a 64 bit operating system or running a file server, so the 4 GB version is quite attractive – it'll suit 64 bit much better than a 1 GB RPi will.
  • If it's not going to be used specifically for 4K media serving (ie, playing 4K videos to a 4K screen) it may work out more expensive than going with the Odroid HC1 because it needs more extras to get it going and Pine64's accessories cost more. Maybe accessories is where Pine64 makes its money.
    • It's also annoying that almost all their prices end in .95 or .99.
  • There are no obvious choices for cases (at Pine64 or anywhere else) that can hold a hard drive.
  • MickMake Rock64 review (with video linked).
  • Explaining Computers video review.

Coming soon and looking somewhat interesting:

Khadas Vim3 Main Features

This high-spec SBC was announced in May 2019 but seemed to have specs changes all the way up to its release date in late June.

The Basic and Pro versions announced are only two versions of the first of three models planned for release.

The Vim3 has a 3 axis accelerometer but not a gyroscope, so it probably won't be much good for motion tracking. The M.2 slot accepts NVMe drives but not SATA drives.

Apart from the price, why wouldn't you want to buy one of these as soon as it becomes available? There are at least four reasons.

1. It will take a while to develop the support and build up the following that other older boards have. This is a significant drawback to being an early adopter. Khadas has not so far been a leading SBC maker.

2. They are rather expensive. The intro prices were not too bad, but the company then announced those prices wouldn't be available to many people, and then announced the actual prices. Ow.

3. Specs seem to be in a state of flux. It now (20 June 2019) seems all the boards will ship with a neural processing unit and a different (but pin-compatible) SoC to that originally stated.

4. Even though 24 June was the "release" date, it seems the boards won't actually ship until mid August.

I can only conclude there's really not much point in ordering one for several months.

The Khadas website is VERY sluggish.

Various anouncements here.

SoC: 64 bit hexa-core Amlogic A311D media player.
CPU: 12 nm Quad-core ARM Cortex-A73 @ 2.2 GHz with dual-core Cortex-A53 @ 1.8 GHz.
GPU: Mali-G52 MP4 at 846 MHz, multi-video decoder up to 4Kx2K@60fps + 1x1080P@60fps (or UHD 10-bit @ 75 fps).
MCU: STM8S003 microcontroller, Cortex-M4 core 209MHz?, for "always-on" or real time processing.
NPU: Component of SoC. Details coming soo..., well, at some point. It's not going to be any use initially because the software for it simply isn't available.
RAM: 2 GB (Basic) or 4 GB (Pro) LPDDR4-1600 (or 4X).
Storage: MicroSD up to UHS-I, 16 GB eMMC 5.1 (Basic) or 32 GB eMMC 5.1 (Pro) onboard, M.2 connector for 2280 NVMe SSD or PCIe 2.0 (an adapter with ribbon cable reverses the direction of the M.2 connector).
GPIO: 40 pin 3.3 V @ 2.54 mm pitch, incl USB 3.0 or PCIe 2.0 (single lane).
USB: 1x USB 3.0 socket, 1x USB 2.0 socket. 1x USB-C power input is also USB 2.0 OTG.
Network: 10/100/1000 Ethernet, 802.11a/b/g/n/ac, 2X2 MIMO with RSDB, Bluetooth 5.0, dual channel IR receiver.
Other: 3-axis digital accelerometer, RTC battery socket (0.8 mm pitch), 2 channel IR receiver, MIPI DSI (FHD), MIPI CSI, 10 pin touch panel connector. Audio 384 kHz, 32 bit stereo audio line output.
Power: 5-20 V via USB-C.
Size: 82.0 mm x 58.0 mm x 13.0 mm. In a slimline acrylic case 92 mm x 66 mm x 22 mm.
Weight: 28.5 grams (to be confirmed). 70 grams in a slimline acrylic case.
Price: 2 GB US$100, 4 GB US$140 (which make the Odroid N2 prices look great); intro prices from 24 June depend on having a Twotter account. Heatsink US$10 (thermal pad, not heatsink compound), fan US$15, DIY case US$15 (or transparent DIY case without metal plate US$5.70). Power adapter US$5.70 but no Aus power adapter available. US$5 discount code for subscribing to email. US$150.59 total for Vim3 4 GB, heatsink, clear case (no metal plate), NO power adapter. Shipping apparently included but shopping cart doesn't work (using a Vim2 as a stand-in).

Bigger alternatives

These boards are bigger than a RPi 3B+ and are generally more powerful with more ports.

Hardkernal Odroid N2 Main Features

This is the first S922X SBC available, and it comes in at a nice price (setting up some good competition for Khadas).

No Wi-Fi or Bluetooth.

Hardware specs. The Cortex M4 may provide wake-on-voice support.

In many areas the Odroid N2 performs only slightly better than the Odroid XU4, but in memory speed, graphics and crypto extensions it's much faster. Performance may increase in some areas with a few years of driver refinement.

SoC: 64 bit Amlogic S922X media player.
CPU: 12 nm quad-core ARM Cortex-A73 @ 1.8 GHz with dual-core Cortex-A53; no thermal throttling with standard heatsink.
FPU: NEON, VFP, Crypto Extensions.
GPU: Mali G52 MP4 @ 846 MHz; 2 shader cores and Odroid says it has 3 Execution Engines per core = MP6; 4Kp60 10-bit H.265.
MCU: Cortex M4.
RAM: 2 GB or 4 GB DDR4-1320.
Storage: MicroSD slot, eMMC connector.
GPIO: 40 GPIO pins, 3.3 V.
USB: 4x USB 3.0 sockets, 1x USB 2.0 micro-B OTG socket.
Network: 10/100/1000 Mbps Ethernet.
Other: RTC battery connector; IR receiver; audio 384 kHz, 32 bit stereo audio line output; composite video out.
Power: 7.5-18 V using 5.5 mm x 2.1 mm DC barrel connector; 12 V, 2 A power supply recommended.
Size: 90 mm x 90 mm x 17 mm; heatsink 100 mm x 91 mm x 24 mm.
Weight: 190 grams including heatsink.
Price: US$63 (2 GB) or US$79 (4 GB).

Nvidia Jetson Nano Developer Kit Main Features

The Nvidia Jetson Nano is a small board with a 260 pin SODIMM interface. It plugs into the larger Developer expansion board, which provides expansion and communication ports such as USB and Ethernet, with which it forms the Developer Kit.

Promised for wide availability in June 2019, with a version of the module with 16 GB eMMC 5.1 onboard flash storage available from August 2019.

It's a little slow for smooth realtime Kintinuous or ElasticFusion, but meets their requirement for CUDA SDK 7.0+, and Kintinuous has install instructions for a Jetson TX1 (and CPU notes; eg, for slow CPUs turn off meshing when loop closure is enabled). It might be pretty good at processing a scan recording, or running Kinect Fusion.

However, this board is strongly intended for AI and deep learning.

The Developer Kit with no accessories (and no eMMC) including shipping works out to the same price as an Odroid XU4 with case, 6 A power supply, RTC battery, 32 GB eMMC, eMMC reader, and Wi-Fi module. The XU4 sadly doesn't have 128 CUDA cores but is much smaller and much lighter.

Note that running the Jetson Nano Dev Kit using the barrel connector requires a jumper which for some unfathomable reason is not included. Why, Nvidia!? It's just a few cents, but a lot of hassle if a customer doesn't have one.

SoC: Tegra X1, unknown model number.
CPU: Quad-core ARM Cortex-A57 @ 1.428 GHz. This is a little outdated.
GPU: GM20B, 128 CUDA core Maxwell @ 921 MHz. (The Maxwell architecture is the predecessor to Pascal.) Good for decoding two streams of 4K @ 30 fps. CUDA Compute Capability 5.3, CUDA SDK unknown.
NPU: GPU capable of 472 GFLOPs (16-bit FP).
RAM: 4 GB LPDDR4, 64 bit, 25.6 GB/s.
Storage: Micro SD card slot. Separately available Jetson Nano module will have 16 GB onboard eMMC.
GPIO: 40 pin RPi compatible.
USB: The Dev Kit has 4x USB 3.0 and a USB 2.0 Micro-B (which can also be used for power input).
Network: Gigabit Ethernet, M.2 Key E for wireless card.
Other: RTC with solder pads – add a CR1220 holder or capacitor. HDMI 2.0 and eDP 1.4, usable at the same time with each running a 4K display. MIPI CSI, GPIO, I2C, I2S, SPI, UART.
Power: 5 V via micro USB @ 2 A, or barrel socket at up to 4 A (switch power input by jumper, not included).
Size: 100 mm x 80 mm x 29 mm for Developer Kit (without a fan). 70 mm x 45 mm System on Module.
Weight: 136 grams.
Price: US$99 plus shipping for Developer Kit, or NZ$178 from NewEgg incl shipping. US$129 for Jetson Nano module with onboard eMMC.

Significantly bigger is a Linux laptop from Pine64, the Pinebook Pro.

  • 14" 1080P IPS LCD monitor.
  • Magnesium alloy body.
  • Rockchip RK3399 SOC with Mali T860 MP4 GPU.
    • ARM Cortex 1.8 GHz dual-core A72 and quad-core 1.4 GHz A53.
    • This is far from my favourite SoC.
  • 4 GB of LPDDR4 RAM.
  • 64 GB of eMMC storage.
  • Bootable microSD card slot.
  • USB-C port.
    • Data, power and video out (at up to 4K @ 60 Hz).
    • USB 2.0 and USB 3.0 connectivity.
  • PCIe x4 to M.2 NVMe SSD Slot (requires optional adapter).
  • Wi-Fi 802.11ac, Bluetooth 5.0.
  • Webcam, microphone.
  • Stereo speakers, headphone jack.
  • 10 Ah Li-ion polymer battery.
  • 5 V, 3 A barrel connector.
  • 22 cm x 33 cm x 2 cm / 1.4 cm (at thickest / thinnest).
  • US$200 + shipping (it has a battery in it, so is "a real pain to ship"), on pre-order as of the end of July 2019.

Pine64 also has a PinePhone and PineTab in development.

Ruled out of contention

Ruled out smaller SBCs than RPi 3B+:

Raspberry Pi 3 Model A+ Main Features

This is a smaller, simpler, cut-down version of the 3B+.

It's a little cheaper than the 3B+ and a little smaller, but for those savings it misses out on a lot. The benchmark results make it look like it's suffered, too.

I'm sure there's a market for it but to me its appeal is quite limited.

SoC: Broadcom BCM2837B0
CPU: 64 bit, quad-core Cortex-A53 @ 1.4 GHz.
FPU: VFPv4 + NEON.
GPU: 1080p30 H.264/MPEG-4 AVC.
RAM: 512 MB shared with GPU.
Storage: MicroSD up to 32 MB.
GPIO: 40 pin.
USB: 1x USB 2.0, direct from SoC.
Network: No Ethernet. 2.4 GHz and 5 GHz IEE 802.11.b/g/n/ac wireless LAN, Bluetooth 4.2/BLE.
Other: MIPI DSI & CSI. No RTC.
Power: 5 V via USB Micro-B.
Size: 65 mm x 56.5 mm.
Weight: 23 grams.
Price: US$25.

Ruled out same size SBCs as RPi 3B+:

Asus Tinkerboard S Main Features

It's nice to see a large computer company making a faster, more capable board targeted as an upgrade from the RPi: all the ports are in the same places as the RPi.

The S is the second version, firmly positioned to be fully compatible with the first version, which is encouraging that Asus has the long haul in mind.

However, making it as much a direct RPi replacement as possible has seen some poor design choices. For example, the USB micro-B socket is not a good connector for high current. Armbian notes: "Severe powering troubles due to Micro USB power connector. It's recommended to power through GPIO pins to prevent under-voltage issues (instabilities, boot/crash cycles). Powering situation is a little improved/masked on model S."

It does not have any USB 3.0 ports, which is a very strong disincentive. For the same money there are more exciting alternatives.

SoC: Rockchip RK3288.
CPU: 32 bit, quad-core ARM Cortex-A17 at 1.8 GHz, up to 2.6 GHz turbo.
FPU: NEON, VFPv4.
GPU: Mali-T764 (some specs say T760) @ 600 MHz (better than the GPU in the Odroid XU4). Claims playback of 4K[actually UHD] @ 30 Hz with H.264/H.265 hardware decoder but doesn't quite manage it in practice.
RAM: 2 GB dual channel DDR3.
Storage: microSD slot, 16GB eMMC onboard (new for the S version, the biggest change).
GPIO: Colour coded RPi compatible 40 pin
USB: 4x USB 2.0.
Network: Gigabit Ethernet, Wi-Fi 802.11 b/g/n, Bluetooth V4.0 + EDR.
Other: HDMI now has CEC support. No RTC.
Power: 5 V, 3 A via USB micro-B socket.
Size: 85.5 mm x 54 mm.
Weight: 55 grams (a little heavier than the heaviest version of the RPi Model B at 46 grams).
Price: $148 from PB Tech (sold out).

Extra notes for Asus Tinker Board S:

  • This second version should perform just as well as the first version did in real world tests, even against more powerful CPUs, although it needs good cooling when run hard.
  • Most of the specs are the same as the Tinker Board, and are mostly minor changes.
  • The Mali T760 GPU was released in October 2013. I cannot find anything anywhere about the T764.
  • Some consider it the best supported fast RPi alternative (but of course is well behind the RPi), but Asus hasn't actually done well at all.
  • Without USB 3.0 it's a little hard to consider it a serious option.
    • There's no physical way to connect an Intel D435 or Asus Xtion 2 to it, or a fast hard drive.
    • It limits its usefulness as a NAS or local cloud server; use an Odroid HC1 or HC2 instead (they have SATA instead of USB 3.0), or a Rock64.
  • Update: With the release of the RPi 4B there's really no point in buying a Tinker Board S. Hopefully Asus will rise to the challenge and make something with a suitable step up in performance from the 4B.
FriendlyElec NanoPi M4 Main Features

This is an interesting RPi sized board from FriendlyARM and has some pros and cons. Appears to have ports in the same places as RPi.

I'm not really sure of the usefulness of having only dual "big" cores. The A72 is not a particularly powerful CPU, and the two cores together have only about 40% more processing power than the four "little" cores.

All six cores working together is only about as theoretically powerful as just the Odroid XU4's four "big" cores, although the M4's four "little" cores are about 26% faster than the XU4's "little" cores.

Apart from CPU processing power, the board as a whole has several advantages over the XU4, such as lots of USB 3.0 sockets and 4K 60p playback.

Just too expensive with the (physically bigger and more powerful) 4 GB Odroid N2 coming in at US$79.

SoC: Hexa-core Rockchip RK3399 media player
CPU: Dual-core ARM Cortex-A72 @ up to 2 GHz and quad-core ARM Cortex-A53 @ up to 1.5 GHz.
GPU: Mali-T864. 4K VP9 and 4K 10 bits H265/H264 60 fps decoding. Dual VOP.
RAM: Dual channel 2 GB DDR3-1866 or 4 GB LPDDR3-1866.
Storage: MicroSD slot, eMMC connector.
GPIO: PCIe x2 headers and 2x independent USB 2.0 headers on GPIO pins.
USB: 4x USB 3.0 sockets.
Network: Native gigabit Ethernet, Wi-Fi 802.11a/b/g/n/ac, Bluetooth 4.1 combo module, dual antenna interface.
Other: RTC battery connector.
Power: 5 V, 3 A via USB-C connector.
Size: 85 mm x 56 mm.
Weight: 48 grams.
Price: 2 GB US$65, 4 GB US$95.
  • Banana Pi, Orange Pi.
    • I don't see any particular attraction for any of these.
    • In mid 2019 the Banana Pi website was one of the worst I've seen – terrible blocky graphics, clearly never heard of a spell checker.
    • They don't offer anything particularly compelling that Raspberry Pi's don't have, they don't have the user base that RPi has, and their software doesn't work smoothly. Why bother saving a couple of dollars to buy one? Not worth further consideration.
  • Libre Computer Board ROC-RK3328-CC.
    • US$35 (1GB, sold out), US$50 (2GB), US$80 (4GB).
    • Seems really overpriced compared to the almost identical Pine64 Rock64 (even with the price drop of US$5 for the two lower models).
    • Main ports difference with Rock64 is this one has power input by micro USB – not a good idea for high current – and does not have the extra GPIO pins.
    • Very new (announced Jan 2018), unknown maker or user support.
    • One of the only RPi-sized boards with 4GB RAM, but get the Rock64 instead; this one is just too expensive. Not worth further consideration.
  • Khadas Vim2.
    • SoC is 64 bit Amlogic S912.
    • CPU: 4x Cortex-A53 @ 1.5 GHz, 4x Cortex-A53 @ 1.0 GHz.
    • GPU: Mali-T820 MP3 @ 600 MHz.
    • Storage: Up to 3 GB DDR4 and 64 GB eMMC.
    • 2x USB 2.0 port (one with 500 mA output, the other with 900 mA), no USB 3.0 ports.
    • Does some nice things like placing the Ethernet port through the board to keep the height down, but without USB 3.0 it's just not attractive to me. Not worth further consideration.

Ruled out larger SBCs than RPi 3B+:

FriendlyElec NanoPC-T4 Main Features

First impression is that this is a Really Clever board.

Mick Make review here, including video.

Out of a bunch of RK3399 boards this is the best I've seen, albeit the biggest.

However, with the 4 GB Odroid N2 significantly cheaper and with a better SoC, and the 1 GB NanoPi Neo4 less than half the price there's now much less reason to buy this one. Even the M.2 isn't a very attractive feature with the pending Khadas Vim3.

SoC: Hexa-core Rockchip RK3399 media player.
CPU: Dual-core ARM Cortex-A72 @ up to 2 GHz and quad-core ARM Cortex-A53 @ up to 1.5 GHz.
RAM: 4 GB dual channel RAM.
Storage: 16 GB eMMC 5.1 onboard, M.2 connector (which places the M.2 card along the back of the board, much more sensible than the HiKey 960).
GPIO: GPIO pins 3 V and 1.8 V.
USB: 1x USB 3.0 socket, 1x USB type-C socket (USB 3.0 and DisplayPort 1.2), 2x independent USB 2.0 sockets.
Network: Gigabit Ethernet, Wi-Fi 802.11a/b/g/n/ac, Bluetooth 4.1; has "Dual Antenna Interface" but it's not clear if this is 2x2 MIMO or just an antenna for each of Wi-Fi and BT.
Other: RTC battery connector.
Power: 12 V, 2 A.
Size: 100 mm x 64 mm.
Weight: 463 grams; even if that includes the heatsink, that's unusually heavy.
Price: US$109.99 on sale.

  • Latte Panda.
    • US$149 + shipping for the 4 GB version.
    • It runs Windows 10.
    • The "Intriductions" and "Spectififcation" headings don't exactly inspire me, especially considering they have been like that for years.
    • Neither do the bullet points in the Key Features list that don't line up (update – they do now).
    • Neither does the "GHz" and "Mhz" (small h) just lines apart, or "5v" (small v) and "5V" just lines apart.
    • Comes with Windows 10 Home Edition preinstalled.
    • 88 mm x 70 mm.
    • 55 grams.
    • Its size, price and operating system means it's not a contender for a direct Raspberry Pi replacement. Not worth further consideration.

Summary

There are a handful of SBCs which should definitely be considered. For the particular tasks they are best suited for, I believe they are classic boards.

  • The Raspberry Pi 3B+ has a great blend of capability, support, and excellent installed user base behind it. However, it has now been superceeded by the 4B. (And it's about time there was a more powerful Raspberry Pi option!)

  • The Raspberry Pi 4B is a excellent extension of the Raspberry Pi line. For general use this is definitely now the one to go for, but it's not cheapest for most of what it offers. However, with such an improvement in benchmarks, the folk behind the RPi 4B can be very proud of what they've produced. These are going to be in big demand! The biggest question for the average user is how much RAM to go for?

  • The Arduino Nano clone is a great little microcontroller at a great price that just sips power, running on a handful of milliamps. For many tasks it's all I need, and is perfect for the simple repetitive tasks that just require switching output pins without any heavy computing.

  • The Pine64 Rock64 offers some good improvements over the Raspberry Pi 3B+ (eg, eMMC, USB 3.0, 4K video, and up to 4 GB RAM, but no onboard Wi-Fi). Processing power is only slightly better than RPi 3B+ (due to its slightly faster clock speed) but not as good as RPi 4B, so it's better suited for non-demanding computing tasks. Excellent for a media server. If you don't specifically want anything the RPi 4B has or are looking for a reasonably inexpensive first step away from RPi, the Rock64 could be the one.

  • The Odroid XU4 is powerful, small and light, and a complete package (including a good Wi-Fi adapter) can be bought for a reasonable price. It has been around for a while, so has a good installed user base, but the SoC is getting a little long in the tooth; there are other boards which do some things a little better (eg, 4K video, crypto extensions). Depending on what it's used for that may not be a problem. Where it does do well, it's excellent.

  • The Nvidia Jetson Nano Developer Kit is an unusual board. It has a CPU significantly more powerful than a Raspberry Pi 3B+, but significantly behind others such as the XU4. Its GPU, on the other hand, is unrivaled by any other "inexpensive" SBC. For deep learning such as image recognition it's an obvious choice, and may be powerful enough to do live or reconstructed (from a recording) meshing of 3D scanned scenes. Sadly it's big and heavy compared to the RPi-sized boards.

Cost of getting up and running with some of these SBCs.

SBC Package Contents Buy Locally Approx. Total Cost (NZ$)
RPi 4B
1 GB
bare bones
Pi 4B (1 GB), power supply, micro-HDMI cable, shipping. 32 GB microSD card $105
RPi 4B
4 GB
bare bones
Pi 4B (4 GB), power supply, micro-HDMI cable, shipping. 32 GB microSD card $139
RPi 4B
4 GB
Pi 4B (4 GB), case, power supply, micro-HDMI cable, shipping. Fast 32 GB microSD card (with A1 rating) $161
Rock64
1 GB bare bones
Rock64 (1 GB), power supply, shipping. 32 GB microSD card $80
Rock64
4 GB bare bones
Rock64 (4 GB), power supply, shipping. 32 GB microSD card $111
Rock64
4 GB
Rock64 (4 GB), heatsink, open acrylic case, power supply, 32 GB eMMC, eMMC USB adapter, USB 2.0 Wi-Fi adapter, shipping. $173
Rock64
4 GB
Rock64 (4 GB), heatsink, open acrylic case, power supply, USB 3.0 SATA adapter, USB 2.0 Wi-Fi adapter, shipping. ≥240 GB SATA SSD
(set as boot drive)
≥$187
XU4
bare bones
XU4 (2 GB), 4 A power supply, shipping. 32 GB microSD card $118
XU4 XU4 (2 GB), case, 4 A power supply, RTC battery, 32 GB eMMC, eMMC reader/writer, Wi-Fi module 5A (ac, dual band), shipping. $187
HC1
home cloud setup
MC1 (2 GB), case cover, 4 A power supply, RTC battery, Wi-Fi module 5A (ac, dual band), shipping. 32 GB microSD card,
≥240 GB SATA SSD
≥$191

Other options may also be worth considering.

  • If size is particularly important the Raspberry Pi Zero W is small and light, but it doesn't have a lot of computing power. Like, very little computing power. (That and the lack of easy connectivity are the reasons I haven't put it in with the classic boards to definitely consider above). The extra cost of the Wi-Fi equipped Zero W is worthwhile.

  • The NanoPi Neo4 is small and a bit more powerful than a RPi 3B+. It may not be lighter, though, due to needing a heatsink, and the standard heatsink is quite hefty. It's a bit expensive considering the XU4 is more powerful, US$1 cheaper and comes with a heatsink.

  • A new board to keep an eye on is the Khadas Vim3. The specs appear to have just significantly changed, only a few days out from "launch"... but it won't actually ship for another couple of months, so it's hardly a launch as we know it. Some more confirmation of specs is called for.