Custom PC – October 2019

GARETH HALFACREE’S

Hobby tech

The latest tips, tricks and news in the world of computer hobbyism,

from Raspberry Pi, Arduino and Android to retro computing

A

lthough everyone knew it was

coming, nobody expected it quite

this quickly: the Raspberry Pi is

dead, long live the Raspberry Pi. To clarify: as

indicated during the launch of the Raspberry

Pi 3 Model A+, the ‘legacy’ Raspberry Pi range

has come to a close. Its replacement, looking

not wholly dissimilar and going under the

name Raspberry Pi 4, is a ground-up

re-engineering effort that aims to finally

address some of the most long-standing

complaints about the low-cost, education-

focusedsingle-boardcomputerfamily.

The heart of the effort is a new system-

on-chip (SoC), the Broadcom BCM2711B0.

The headline-grabbing features are four

1.5GHz ARM Cortex-A72 CPU cores and

an all-new VideoCore VI GPU – making it

the first Raspberry Pi in history to launch

without the aging VideoCore IV.

Inside, there’s an even more welcome

change. The main bottleneck of the Raspberry

Pi design, from the original Model B through to

the range-topping Raspberry Pi 3 Model B+,

has gone. The SoC now enjoys around 5Gb/

secofbandwidthtoconnectwithexternal

devices,insteadoftryingtoshoveeverything

througha single480Mb/secUSBlane.

Thathasa seriousimpactontheRaspberry

Pi’scapabilities.WherethefourUSB2 ports

wouldpreviouslyhavesharedbandwidth,not

onlyaretheynowfullyindependent,buttwo

ofthemhavealsobeenupgradedtoUSB3.

Likewise,wherethe‘Gigabit’Ethernetofthe

RaspberryPi3 ModelB+wouldtopoutat

around250Mb/sec,thePi4’sportgetsabout

asclosetoGigabitspeedsasyoucouldhope.

There’sstillmoretothePi4 aswell.The

shifttoanall-newSoChasbrokenthe1GB

memorybarrier,withthePi4 launchingin

1GB,2GBand4GBvarieties– andit’sall

LPDDR4memory,ratherthantheolder

models’LPDDR2.TheupgradedGPUnow

alsoincludesdual-displaycapabilities,with

theboarddesigntradingthetraditionalfull-

sizedHDMIportfora pairofmicro-HDMI

connectors,eachabletodrivea 4Kdisplay–

eithera single4K60ortwo4K30panels.

Plusthere’sa hardwaredecoderforHEVC

REVIEW

Raspberry Pi 4

CUSTOMISATION / HOBBY TECH

The new BCM2711B0 is the Foundation’s first SoC

to be built on a 28nm process node

The layout has been shuffled, with the Ethernet port

now at the top