Just what can you do with the most powerful Raspberry Pi to date?
In 2016 Eben Upton, the co-creator of the multi-million selling $35 Raspberry Pi, said there was little more power that could be wrung from the tiny computer without a major overhaul.
It turns out there was more untapped potential in the board than first thought, as today saw the release of the most powerful Pi yet, the Raspberry Pi 3 Model B+.
Upton describes the board as kind of a Raspberry Pi 3.5, not a generational leap over the 2016's Pi 3 but a step up that delivers a decent boost to performance and Wi-Fi speeds.
The headline improvements to the Raspberry Pi 3 Model B+ are that the CPU has been overclocked to 1.4GHz -- a leap of 16.7% -- and the addition of 802.11ac Wi-Fi -- which almost triples the throughput of the Pi 3 Model B's 2.4GHz 802.11n Wi-Fi -- while the price remains at $35.
"It's not a Raspberry Pi 4. I think what we've ended up with is something which is a really good B+, a bit too good for a B+, but that would be not really anywhere near enough for a Raspberry Pi 4," said Upton.
"The B+ is our attention-to-detail spin for the product, where we take all the stuff we've learned in the past couple of years and smoosh it all together and make a new thing that addresses some of the concerns or takes advantage of some of the opportunities that have come along in the intervening time."
The B+ will be of particular interest to enthusiasts pushing the existing Pi 3 to its limits, says Upton, giving them the overhead to try out new things with the Raspberry Pi.
"If you have 15 percent more CPU, a bunch more network and better thermals. Then all of a sudden things that just about worked and were marginal become very comfortable on the platform."
The good news for those wanting to see how far they can push the new Pi 3 B+ is that its CPU is less prone to throttling its speed when under prolonged heavy load, thanks to a new heatspreader on top of the chip.
"While you still can if you run a completely insane benchmark, it's much harder to push a Pi 3 B+ into thermal limits than it is a Pi 3," says Upton.
Those new uses could include a more capable media center, with the B+ able to comfortably play a wider range of video, due to its better performance and recent support for hardware-assisted decoding of HEVC 1080p H.265 video. The power bump could also broaden the Pi's use in running machine-learning models, says Upton, who cites this Pi-powered cucumber sorter as one of his favorite uses of AI on the board to date.
SEE: Hardware spotlight: The Raspberry Pi (Tech Pro Research)
The B+ will also make for a better home server than the vanilla Pi 3, thanks to its improved data transfer. The addition of 802.11ac Wi-Fi support effectively tripled the wireless throughput to about 100Mb/s in testing, while the addition of Gigabit Ethernet over USB 2.0 ups the maximum wired throughput to about 300 Mb/s, more than double what was previously possible.
While the USB and Ethernet share the same data bus, so you won't be able to sustain full Gigabit Ethernet speeds, Upton says it offers a "noticeable improvement in a lot of use cases". Another plus for those using the Pi with a wired Ethernet connection is the inclusion of support for a Power Over Ethernet [POE] Hardware Attached on Top [HAT] board, which will add the ability for the Ethernet cable to power the board.
New operating systems and full Windows 10
The Pi already runs a plethora of Linux-based operating systems and desktops, and the extra reserves in the B+'s tank should help widen the range of viable choices.
"Like I say, everyone gets a shot in the arm. We like the Ubuntu stuff, that's been very popular, the Fedora guys have done some great work recently. Every little helps," said Upton.
And while the release doesn't expand on the Windows 10 offerings for the Pi, Upton says he would still like more options for people that want to run traditional x86 Windows apps on the Pi.
"It's still something I'd like to see. Those people who want the ability to run Microsoft Windows applications, particularly x86 Windows applications, there is a population of those people and they're people we can't really address at the moment," he says.
What's the plan for the Raspberry Pi 4?
Upton originally indicated the Raspberry Pi 4 would be released around 2019, but he says that given the release of the Pi 3 B+, "I wonder if this stretches that a little bit," adding the next major new board would likely be based around a new system-on-a-chip.
"We've found a few extra tricks up our sleeve to get one more half generation improvement out," he said.
"It's pretty obvious that we really are at the thermal limit now. We can add as many extra transistors as we want, but we can't afford the toll in the thermal footprint of the device.
"I think it's inevitable that for the next board we'll have to have some other chipset. You can safely say by 2021 we'll likely be shipping a Pi 4, and that's conservative I hope.
"What's it going to look like? I think it will look like a Pi 3 but more," he said, adding he felt the Pi was now a feature-complete device following the addition of Wi-Fi with the release of the Pi 3.
The launch of the Pi 3 B+ doesn't mean the older models will be taken off the market. All of the previous generation boards will remain on sale, their respective prices remaining unchanged.
While that may seem counterintuitive, Upton says it makes sense to keep the prices the same, as while the earlier generation boards are cheaper to make, diminishing demand means the cost remains fairly static.
While the vast majority of existing Pi cases and add-ons will be compatible with the new Pi 3 B+, the addition of a keep-out on the bottom of 4-pins that add support for the POE HAT, and the new heatsink on the CPU means some will no longer fit -- although Upton says no more than a handful will be affected. Probably the most widely used case likely to be affected will be the Flirc series, which may contact the heatspreader on top of the chip.
The good news for owners of existing Pi boards is that the Raspberry Pi Foundation has committed that no Pi board will hit End of Life until 2022, with a commitment to produce the Pi 3 B+ until at least January 2023.
18 million boards and counting
The Pi has proved to be somewhat unstoppable, selling more than 18 million boards since its launch in 2012, and with that momentum showing little sign of slowing down.
"Hopefully we'll go past the 20 million point in the first half of this year, with luck," says Upton.
"It's a lovely number you know," adding "it's a long way from 1,000 right?", a nod to the foundation's rather conservative expectation of how many boards they would sell.
Money from sales of the Pi are ploughed back into the Raspberry Pi Foundation, a registered charity whose aim is to encourage more people to learn about computing by making low-cost computers widely available. Today the foundation, and Raspberry Pi Trading, which handles engineering and sales of the boards, employ about 120 people, and the foundation's education outreach is helping some 100,000 children each week.
Beyond the educational success, Upton takes some pleasure in helping to drive the cost of computing down to the point where an actually useful machine could be bought for less than a tank of gas.
"What's really nice is that before we started doing this is that there weren't these little boards for under $100.
"Now there's lots of stuff for under $100 and people are exploring lots of price-performance-quality points."
It's a testament to the success of the Pi just how many of these rival boards sport similarly fruity names, from Orange to Banana Pi.
However, Upton says he's yet to see a board that hits the same balance between price and performance offered by the Raspberry Pi.
"I haven't seen anything that makes me think 'Wow, I wish I built that'.
"There's no-one who's landed on a point in that multi-dimensional space that I wish I got to first. I think we're still building the product that I and the other people in this office would buy ourselves, and that's been a big thing for us."
SEE: The best alternatives to the Raspberry Pi (free PDF) (TechRepublic)
The release of the Pi 3 B+ will likely drive a fresh spike in Pi sales, even if the Upton and his colleagues are being quite modest about the new board.
"We're being quite British about it and being quite reticent about selling this. It's an incremental update, it isn't Pi 4 right?
"But actually this big stack of incremental upgrades seems to have created something where the people we've sent them out to have been really psyched about it."
Read more about the Raspberry Pi 3 Model B+
- Raspberry Pi 3 Model B+: An insider's guide (free PDF)
- Raspberry Pi 3 Model B+ review: Hands-on with the new board
- Everything you need to know about the Raspberry Pi 3 Model B+: A guide to the fastest Pi yet
- Raspberry Pi 3 Model B+: See all the new features on the board
- Raspberry Pi 3 Model B+: A guided tour of the new board
- How to set up your Raspberry Pi 3 Model B+