The Raspberry Pi has taken the embedded device world by storm since its release. It is a cheap, tiny, low-power, single-board computer that is capable of running a general-purpose operating system, which allows rapid and cheap prototyping of new ideas. However, low-power and cheap contribute to the RPi’s inherent weakness: low performance. The latest Raspberry Pi boasts increased performance, and it delivers a significant boost in I/O performance, but CPU-heavy tasks will continue to languish.
We have run a couple of quick benchmarks to establish the performance characteristics of the new Pi 4B, and are thrilled with the huge performance boost.
|Pi 4||Pi 3B+||Pi 3B||Pi 2||UpBoard|
|iperf loopback||3.28 Gbits/sec|
|iperf wired network|
|USB disk sequential read||200MB/sec|
|USB disk sequential write|
|SD card sequential read||45MB/sec|
|SD card sequential write|
|CPU idle power draw||730mA|
|CPU load power draw||980mA|
iperf loopback: good indication of CPU, memory, and TCP stack performance of the system. Commands: iperf3 -s & iperf3 -c 127.0.0.1
iperf wired network: indication of network I/O performance. Commands: iperf3 -s (iperf3 -c is run from another much faster computer)
USB disk sequential write: indication of USB I/O performance. Commands: dd if=/dev/zero of=/mnt/usb-disk.img bs=1M count=10240
USB disk sequential read: indication of USB I/O performance. Commands: dd if=/mnt/usb-disk.img of=/dev/null bs=1M count=10240
SD card sequential write: indication of SDIO or MMC I/O performance. Commands: dd if=/dev/zero of=/sd-disk.img bs=1M count=10240
SD card sequential read: indication of SDIO or MMC I/O performance. Commands: dd if=/sd-disk.img of=/dev/null bs=1M count=10240
CPU idle power draw: indication of how much power the RPi is drawing when idle. Read USB power meter 10 minutes after boot.
CPU idle power draw: indication of how much power the RPi is drawing when its CPU is under load. Read USB power meter for 5 minutes during boot.
WiFi2Work is using Raspberry Pi computers for embedded projects, including as LoRaWAN radio gateways and application servers. The significant I/O performance boost is welcome, and the expanded memory capacity is wonderful, but we recognise the limitations of the CPU core and will continue to recommend offloading CPU-intensive work to faster computers.