Raspberry Pi 4 Review and Benchmarks

Jarret B

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For those who haven’t heard, the newest version of the Raspberry Pi (RPi) has been released. Technically it is the Raspberry Pi 4 Model B (RPi4). The Raspberry Pi 4 is a 64-bit single board system. The single board measures 3.5 x 2.3 x .76 inches in size. The board contains the following:

  • Processor: System on Chip (SoC) ARMv8 64-bit quad-core 1.5 GHz Cortex-A72
    • Graphics: 500 MHz VideoCore VI built-in to the SoC
  • RAM: 1, 2 or 4 GB DDR4
  • Bluetooth – 5.0
  • USB:
    • 2 – 2.0
    • 2 – 3.0
  • Network:
    • 2.4 GHz and 5 GHz 802.11 b/g/n/ac Wi-Fi
    • Gigabit Ethernet port
  • Storage: Micro-SD slot
  • Video: 2 4K video micro-HDMI ports
    • 1 port 4K @ 60 Hz refresh rate
    • 2 ports 4K @ 30 Hz refresh rate
  • Power: USB-C port 5V and 3A
  • AV Jack: 3.5 mm
  • Camera connector Camera Serial Interface for RPi Camera Module
  • Display Connector: Display Serial Interface (DSI) for RPi Touch Display
  • Connection: General Purpose Input/Output (GPIO) header allows connection of other hardware

These are the highlights of the RPi4 board. Let’s look at some of these in more detail.

SoC Processor

A System-on-Chip (SoC) is a Central Processing Unit (CPU) with other components built into the same chip. In the RPi4 the Graphical Processor Unit (GPU) is built-in to the CPU. Nearly every component on the board can be integrated into the CPU.

The Advanced RISC Machine (ARM) is made by the Arm Holdings which only develops designs. The ARM Holdings does not produce the chips but produces the designs of the processor and separate Intellectual Property (IP) Blocks.

An IP Block will consist of one component. For example, an IP Block can contain the design for a USB Hub Controller. Another example would be an IP Block for Bluetooth.

NOTE: Keep in mind that the IP Block has the specifications to include the IP Block components to be placed into the SoC (CPU) chip.

At the current time the newest architecture version is ARMv8 which is a 64-bit design. The ARM Core implementation is the Cortext-A72. The SoC is the Broadcom BCM2711 on the RPi4 hardware. Basically the ARM design allows for backwards compatibility. Software which runs on a Raspberry Pi 3 should run on a Raspberry Pi 4. Since the RPi4 is a 64-bit system you can run a 64-bit or 32-bit OS on it.

NOTE: The RPi3B+ has an ARMv8 64-bit CPU. The processor is an SoC Cortex-A53.

There are three variations of the ARM processor:
  1. Application: runs an OS
  2. Real-time: manages a hard drive or SDD device (usually does not run an OS)
  3. Microcontroller: Energy efficient devices
NOTE: The RPi4 has an Application SoC (Cortex-A72).

Each SoC which has an identical IP Block as another SoC in most cases would use the same device driver. For example, the Bluetooth IP Block on one SoC will use the same device driver as another SoC using the same Bluetooth IP Block.

NOTE: The OS should be the same for the driver to be the same. For example, two SoC chips on two Ubuntu systems would use the same component driver if both chips had an identical IP Block for that component.

DDR4

Double Data Rate 4 (DDR4) Synchronous Dynamic Random-Access Memory (SDRAM) is the RAM used on the RPi4.

DDR4 was used since it uses less power than the DDR3 used on RPi3 but higher performance.

The highlights of DDR4 memory chips are as follows:

  • Lower power (1.3V)
  • Faster data transmission (1600 – 3200Mb/s)
  • 288 pin DIMM

The point here is that the RPi4 has faster RAM but mainly that less power is used. I remember using the RPi3 and occasionally having low power. Some issues in the past with the previous Raspberry Pi 3 system was low power. It was necessary at times to have a 3.1 amp power supply connected to the board.

Storage

The storage is the one area that you can make things better for your system.

The micro-SD card should be above a Class 6, preferably a Class 10. The size should not exceed 128 GB. You should stick to more name brand SD cards since it is considered the ‘hard drive’ of the system.

Keep in mind what Operating System (OS) you will be using. If you were to use ‘Retropie’ then you may want more storage for the game ROMs.

Power

The RPi4 requires enough power to allow for the use of a lot of connected peripherals. If you order a kit then you get a 5V power supply at 3 amps using a USB-C connector. The wattage is shown as 15.3 watts making the device 3 amps with 5 volts.

If you do not order a kit then you should look for a similar type power connector. Connectors can be purchased at any store which sell cables for phones. Newer phones are using the USB-C connectors.

Video

The RPi4 has a two micro-HDMI ports. If you use only one port then the output is 4K at 60 Hz or 60 frames per second. If both ports are used then the frame rate drops to 30 frames per second per port.

Video quality is supported by the the SoC which has built-in support for H.265 decoding. The H.265 video compression allows for double the efficiency over the H.264 compression.

USB

Another major improvement is the addition of two USB ports which support the USB 3.0 standard.

The USB 2.0 sockets are gray in color while the USB 3.0 ports are blue.

The USB 2.0 speed can get up to 480 Mb/s and USB 3.0 can achieve 4.8 Gbps.

NOTE: It is best to use slower peripherals on the USB 2.0 ports such as the keyboard and mouse. Use the USB 3.0 ports for the faster peripherals rated for USB 3 such as USB sticks.

Bluetooth

The Bluetooth chip supports Bluetooth version 5.

Bluetooth version 5 has more capabilities than the previous versions of Bluetooth. Bluetooth 5 has a range of 800 feet between devices. Data transfer can reach speeds of 2 Mb/s. Bluetooth 5 can allow for multiple devices to connect to another. For example two headphones can connect to a Bluetooth enabled audio player.

Bluetooth 5 devices can detect interference and prevent it from affecting the data transfer.

Benchmarks

I will run a comparison of the Raspberry Pi 4 Model B to the Raspberry Pi 3 Model B+. For the tests I used HardInfo 0.6-Alpha. To make things easier I used the same SD card in both systems as well as the same peripherals (keyboard and mouse).

NOTE: At the time of this writing Raspbian works for both the ARMv7 and ARMv8. Raspbian is only a 32-bit Operating System (OS).

Seven tests were run and are as follows:

  1. CPU Blowfish – tests file encryption speeds
  2. CPU Cryptohash – produces a checksum
  3. CPU Fibonacci – produces a Fibonacci number
  4. CPU N-Queens – algorithm to test the CPU in which a specific number of Queens are placed on a chess board and not two are in the same row, column or diagonal with each other
  5. CPU Zlib – used to test compression speeds of a CPU
  6. FPU FFT – an algorithm used to analyze waves such as in audio files
  7. FPU Raytracing – tracing light as it interacts with objects
Now that you have a basic understanding of what the tests perform you can see where some tests may have higher values than others. All of the tests show better performance if the numbers are lower except for the Cryptohash test which should be a larger number.

The comparisons are as follows:

  • CPU Blowfish – RPi4: 6.86 RPi3: 10.64
  • CPU Cryptohash – RPi4: 354.60 RPi3: 128.76
  • CPU Fibonacci – RPi4: 2.31 RPi3: 4.00
  • CPU N-Queens – RPi4: 11.62 RPi3: 9.41
  • CPI Zlib – RPi4: .26 RPi3: .13
  • FPU FFT – RPi4: 5.43 RPi3: 11.98
  • FPU Raytracing – RPi4: 2.89 RPi3: 7.0
If I were to take the average of both sets of tests (minus the Cryptohash test) then the results would be:
  • RPi4: 4.87 seconds
  • RPi3: 7.19 seconds
NOTE: The Cryptohash test was not used for averages since all others are based on lower numbers rather than higher numbers.

It is apparent that the Raspberry Pi 4 is nearly 68% faster than the Raspberry Pi 3 for these tests.

Heating Issues

Let’s look at some temperature readings at various stages of a system update.

NOTE: The readings were taken with a laser/infrared thermometer.

The first reading was taken before the RPi4 was plugged in. The RPi4 was set up before it was turned on and had been cooled. The values are all given in Fahrenheit and the time is counted after the power was turned on.

Time CPU RAM

0 77.3 77.3
5 91.4 105.4
10 117.0 123.0
15 99.3 122.9

NOTE: The update stopped around 14 minutes and 36 seconds causing the CPU and RAM to coll off a little.

When nothing was running for a while the CPU was at 100.7 and the RAM at 118.9.

I started Minecraft Pi and the values were 103.7 for the CPU and 125.0 for the RAM.

Overall Conclusion

The RPi4 is a better improvement over the RPi3 in all of the hardware upgrades made to it.

There seem to be complaints about heating issues but this will occur on any type of higher end processor. If you run an RPi4 then you may want to invest in a fan to keep it cool.

The uses of the RPi4 are numerous for many projects which could benefit from a small system board. The Internet has many projects listed with designs for building anything you may want. These designs can range from arcade game consoles to sensors within your house. There are also designs for robots as well.

Once there are 64-bit Operating Systems available for the RPi4 then things will be more interesting. It is possible to get a 64-bit OS to work, but it requires a bit of hoops to jump through to make it work.

Look online for an RPi4 and try one out. They come with either 1, 2 or 4 GB of RAM.
 

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