Raspberry Pi 4 Model B review: This board really can replace your PC

The Raspberry Pi 4 is a true next-generation Pi, with dual-screen 4K support, USB 3.0, a new CPU and GPU, and up to 4GB RAM.

Raspberry Pi 4: A guided tour of the new board A walk-through of all the features on the most powerful Raspberry Pi released yet.

The Raspberry Pi 4 is a massive leap forward for the low-cost computer, marking a number of firsts in the evolution of the best-selling board.

Designed to let people experiment with building software and hardware, the Raspberry Pi has always been defined by its users, and they've certainly come up many uses for the Raspberry Pi -- media centers, file servers, Pi-hole ad-blockers, drone control units, and retro-gaming consoles.  

These users will be well-served by the Raspberry Pi 4, but for the first time anyone looking for a budget desktop PC should also seriously consider the Raspberry Pi, a remarkable achievement for a $55 computer.

There are the expected upgrades: the leap to 4GB of fast memory, support for 4K displays, true gigabit Ethernet, the bump in processor speed to 1.5GHz, the inclusion of USB 3.0, and move to a new, more modern system-on-chip. But there are also surprises: the ability to run dual displays and moving past the $35 price tag that's been in place since the first board launched in 2012.

Breaking the Raspberry Pi's $35 ceiling may seem controversial to some, but, to me, it feels sensible to give users more choice.

The base Raspberry Pi 4 Model B is still available for $35 with 1GB LPDDR4 memory, but for the first time users can pay more to get more memory, with a $45 Raspberry Pi 4 offering 2GB memory and a $55 board 4GB memory.

Most importantly, that bump in memory has unlocked what is possible with the Raspberry Pi and how comfortable it feels to use.

SEE: Raspberry Pi 4: This thing is a PC, says board's creator Eben Upton (TechRepublic)

The Raspberry Pi 3 B+ was a half-decent desktop PC, but for everyday use the Raspberry Pi 4 feels close to my work laptop -- a machine costing around 20 times the price. 

I tested the 4GB Raspberry Pi 4 Model B using a pre-release version of the Raspbian OS, based on the forthcoming Debian 10 Buster release. The extra memory eases old pain points when using the Raspberry Pi, to the extent they're barely noticeable. There's no delay when clicking between multiple tabs in the browser and it handles heavy web apps like Gmail and Google Docs with ease. Using Docs felt identical to using it on a budget PC, something that wasn't true of earlier boards, and modern JavaScript and ad-heavy websites also only cause the mildest of stutters when loading.

That all-round improvement is reflected in the synthetic benchmarks (see results below), with the Raspberry Pi 4 comfortably ahead of its predecessor, the Raspberry Pi 3 B+, in CPU benchmarks and far in front in those measuring web performance. That said, the Raspberry Pi 4 generally lagged behind some of the more powerful and similarly priced single-board competitors, like the Rock Pi 4 and NanoPi NEO4 in tests. 

As mentioned in reviews of those Raspberry Pi rivals, however, the benchmarks don't tell the whole story, with the impressive results achieved by these Pi competitors often undercut by uneven general performance and an overall lack of stability.

And while the Raspberry Pi's performance as a desktop may be of little interest to some users, the improved specs shine in other areas. Compiling code for the classic 90s shooter Quake III saw the Raspberry Pi 4 complete the process significantly faster than the Raspberry Pi 3 B+, shaving 1 minute 40 seconds from the build time.

Storage is once again typically handled by SD card, although the addition of USB 3.0 offers a faster port for hooking up rapid SSD storage -- although most SSDs will still be bottlenecked by USB 3.0.

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The Raspberry Pi 4 adds support for dual displays.

Image: Nick Heath / TechRepublic

That said, I did run into some areas where I was unable to test the Raspberry Pi's performance properly, likely due to running an alpha release of the Raspbian OS on a pre-release board.

Sadly I was unable to try out one of the board's headline features, the ability to support dual displays at once, as one of the board's two micro-HDMI ports wasn't working.

Raspberry Pi co-creator Eben Upton told me the dual micro-HDMI ports should be able to support up to two 4K displays at 30Hz or a single 4K display at 60Hz. I also saw the feature working on another board, with the Raspbian desktop being split across two displays and playing back an online video without any issues. I was able to get my Raspberry Pi 4 working with a 2016 Samsung TV at 4K @ 30Hz, which seemed to work fine, although obviously it was slightly less smooth than running the display at 60Hz at 1920 x1080 resolution.  

Another area that I was unable to test properly was media center performance, as I only had a pre-release version of Raspbian, where media playback hadn't been optimized. In my tests using VLC and OMXPlayer on Raspbian, I was only able to get a smoothish frame rate when playing a 1080p, 30 FPS, H.264-encoded video, the Big Buck Bunny test video, during which I also encountered screen tearing. Above that resolution or frame rate, playback either wasn't smooth or the video didn't play at all. I also had trouble with 3D graphics, with Quake III only achieving 5.8 FPS during the 'timedemo' at high settings, some way below what the GPU is capable of.

However, Upton says the Raspberry Pi 4's new VideoCore 6 GPU can playback 4K@60FPS H.265-encoded video, and that this is being targeted for support in the Kodi media center on the Raspberry Pi 4 at launch. He says that improving performance on the Raspbian desktop will be looked at post-launch.

For me, it was a similarly mixed picture when it came to online video playback, with 1080p30 YouTube video being completely smooth, while 1080p60 videos constantly stopped and started, and both suffering from screen tearing. Upton also says fixing screen tearing will be an issue that will be focused on post-launch. After the Raspberry Pi 4 launches I'll run these tests on the board again and update the review.

I was using an early Raspberry Pi 4 board and software, however, and these issues should be resolvable. My overall impression of the Raspberry Pi 4 is that, in narrowing the performance gap with other single-board computers, the Raspberry Pi has cemented its position as the best all-round single-board computer.

It's true that the Raspberry Pi exists in a far more crowded field than in 2012. Competitors have grown a veritable feast of Pi fruit-themed rivals, including Orange, Banana, and the slightly less appetizing Rock Pi.

Some of these rival boards are relatively decent, such as the Rock Pi 4, but they tend to either be more expensive, or more unreliable and relatively unstable, such as the Orange Pi boards and, to a lesser extent, the recent Nano Pi Neo 4.

SEE: More Raspberry Pi coverage (TechRepublic Flipboard magazine)  

What makes the Raspberry Pi a tastier prospect than these underbaked namesakes is its stability. No other Arm-based single-board computer can match the Raspberry Pi for offering a low-cost machine that just works, that has such a broad suite of software, and a huge community to offer support and generate guides and tutorials. Of course, there are x86-based boards that offer stability and breadth of software support, but these almost always cost more than the Raspberry Pi. And as a developer -focused machine, few computers match the Raspberry Pi for the suite of programming-related editors and tools bundled with the default Raspbian OS. The Raspberry Pi 4 will launch with a new version of Raspbian based on Debian Buster.

It's worth remembering that the goal of the Raspberry Pi is to provide a low-cost computer for kids to use to learn about how computer hardware and software works. For those fledgling developers, the gap between it and a low-cost laptop has never been smaller. With the addition of dual-screen support, the Pi now arguably offers more than many laptops, particularly for devs hungry for extra screen space.

But, of course, the Raspberry Pi has become far more than an everyday computer, and even for tech enthusiasts who run the Raspberry Pi as a media center, or retro gaming machine -- the bump to performance, memory, and port speed will likely prove an attractive prospect.

The Raspberry Pi 4 is a compelling machine -- offering all-round performance, stability, and software that's difficult to beat for the price.  

If you're not among the 25 million people who already own one of the boards, there's never been a better time to sample some Raspberry Pi.

  • The Raspberry Pi 4 Model B is available now via official resellers online and the Raspberry Pi store in Cambridge in the UK, as well as from Micro Center stores in the US from later this week.

SEE: Inside the Raspberry Pi: The story of the $35 computer that changed the world (cover story PDF) (TechRepublic)

Specs comparison: Raspberry Pi 4 Model B vs Raspberry Pi 3 Model B+

The Raspberry Pi 4 Model B has a faster and more modern processor than the Raspberry Pi 3 Model B+

The new BCM2711 system-on-a-chip (SoC) used by the Raspberry Pi 4 relies a quad-core 1.5GHz Arm Cortex-A72 based processor, manufactured using 28nm process node technology, and has a newer and more efficient architecture than that found in the Raspberry Pi 3 B+. 

The Raspberry Pi 3 B+ has a quad-core 1.4GHz Arm Cortex-A53 CPU on the older BCM 2837 SoC.

The Raspberry Pi 4 Model B has similar wireless connectivity to the Raspberry Pi 3 Model B+

The Raspberry Pi 4 B offers 802.11ac Wi-Fi, the same as the Raspberry Pi 3 B+, but sports Bluetooth 5.0, compared to Bluetooth 4.2 on the Raspberry Pi 3 Model B+.

The Raspberry Pi 4 has up to four times the memory and has faster memory than the Raspberry Pi 3 B+

The Raspberry Pi 4 is available with 1/2/4GB of LPDDR4 memory, compared to 1GB of LPDDR2 memory in the Raspberry Pi 3 B+.

The Raspberry Pi 4 has faster Ethernet than the Raspberry Pi 3 Model B+

Both boards have gigabit Ethernet, but the speed of the Raspberry Pi's 3's Ethernet is constrained by relying on a USB 2.0 bridge, which limits the maximum throughput to about 300Mbps, compared to true Gigabit Ethernet on the Pi 4.

The Raspberry Pi 4, like its predecessor, will support Power over Ethernet (PoE), which as with the Pi 3 B+ will require a separate add-on board, with plans by the Pi Foundation to release a new PoE board -- though existing PoE boards will work with the Pi 4.

The Raspberry Pi 4 has faster USB ports than the Raspberry Pi 3 Model B+

The Raspberry Pi 4 has two USB 3.0 ports and two USB 2.0 ports, compared to the four USB 2.0 ports on the Raspberry Pi 3 B+.

The Raspberry Pi 4 is the same size as the Raspberry Pi 3 Model B+

Both the Raspberry Pi 4 and the Raspberry Pi 3 B+ measure 85.6mm × 56.5mm.

The layout of the Raspberry Pi 4 is slightly different to that of the Raspberry Pi 3

On the Raspberry Pi 4, two micro-HDMI ports replace the Pi 3 B+'s HDMI port, while the Ethernet port and the USB ports switch places, and there's a USB Type-C power port.

Due to the changes in layout, the Raspberry Pi 4 doesn't fit very well into previous Raspberry Pi cases, as the side panels don't align with the new ports.

The Raspberry Pi 4 is compatible with earlier Raspberry Pi's hardware add-ons

As with earlier boards, there's a 40-pin expansion header for connecting to boards, sensors and other hardware, with the same pin layout as earlier boards. 

The only difficulty might arise from the slightly different layout of the board, although the profile is similar to earlier boards.

The Raspberry Pi 4's GPIO header also supports more connections, with UART, SPI, and I2C interfaces each supported on four additional pins, and with fixed support for clock stretching over I2C interfaces.

The Raspberry Pi 4 can output to 4K displays, supports dual monitors, and should be capable of 4K video playback

The Raspberry Pi 4 supports HDMI 2.0, is able to output video to dual displays, up to twin 4K@30Hz screens or a single 4K@60Hz monitor, via its two micro-HDMI ports.

With the help of the VideoCore 6 GPU, it should be able to playback 4K@60FPS H.265-encoded video, compared to the Raspberry Pi 3 B+, which is capable of smooth video playback at resolutions up to 1080p and has a HDMI 1.3 output.

The Raspberry Pi 4 uses a USB Type-C port for power

The Raspberry Pi 4 uses a USB Type-C port for its 5V/3A power supply, compared to the micro-USB power connector on the Raspberry Pi 3 Model B +.

How does the Raspberry Pi 4 Model B (4GB) perform relative to other Pi boards?

General performance

The Dhrystone benchmark measures the general CPU performance, focusing on calculations using integers.

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The Whetstone benchmark measures another aspect of processor performance -- this time how the CPU handles floating point calculations.

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Used in supercomputer testing, the Linpack benchmark also measures how rapidly a machine can handle floating point calculations.

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Sysbench is another measure of general CPU performance -- here showing single-core and multi-core performance of the two boards.

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While compiling code into an executable program isn't a common activity for the average user, the Raspberry Pi is aimed at helping people to learn about software development. Here's how long it took to build the Quake III code from this GitHub repo.

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Connectivity

This iPerf benchmark measures the speed at which data is transferred between two computers, in this case between an Ethernet-wired PC and various models of Raspberry Pi. These figures are a guide rather than absolute measures, since network speed can be affected by many factors.

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Web browsing

The Octane benchmark may be deprecated, but it still provides an idea of how the Chromium browser in the Raspberry Pi's default Raspbian OS handles JavaScript, the default scripting language of the web. If your browser is slow at JavaScript, it's slow full-stop.

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Raspberry Pi 4 Model B specs

  • System-on-a-chip: Broadcom BCM2711   
  • Processor: Quad-core 1.5GHz Arm Cortex-A72 based processor
  • Memory: 1/2/4GB LPDDR4 RAM
  • Connectivity: 802.11ac Wi-Fi / Bluetooth 5.0, Gigabit Ethernet
  • Video and sound: 2 x micro-HDMI ports supporting 4K@60Hz displays via HDMI 2.0, MIPI DSI display port, MIPI CSI camera port, 4 pole stereo output and composite video port
  • Ports: 2 x USB 3.0, 2 x USB 2.0
  • Power: 5V/3A via USB-C, 5V via GPIO header
  • Expandability: 40-pin GPIO header

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