Raspberry Pi 3 Model B+

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The lat­est Pi’s SoC is 200MHz quicker than the Pi 3, and it also runs cooler.

Raspberry Pi 3 Model B+

Let’s start with a clar­i­fi­ca­tion: the Raspberry Pi 3 Model B+ isn’t a Raspberry Pi 4, which is now un­likely to ap­pear be­fore 2019. The core of the Pi 3 B+ is the same Broad­com BCM2837 pro­ces­sor that pow­ers the Pi 3, although you’d be for­given for not recog­nis­ing it, thanks to a de­sign over­haul, which sees the plas­tic chip pack­age ditched in favour of a more desk­top-like, sil­i­con-die-un­der­heat­spreader approach.

That shift in de­sign, which gives the

BCM2837 its B0 suf­fix, is re­spon­si­ble for two key ad­van­tages. The first is that, along with a new cus­tom-de­signed power management in­te­grated cir­cuit (PMIC), which pro­vides more ac­cu­rate and sta­ble volt­age reg­u­la­tion while con­sid­er­ably sim­pli­fy­ing the cir­cuitry, the Pi 3

B+ runs at 1.4GHz to the Pi 3’s 1.2GHz. The sec­ond, more im­por­tant, ad­van­tage is that the BCM2837B0 is now sig­nif­i­cantly more ef­fi­cient at rid­ding it­self of heat.

A com­par­a­tive look at the two boards un­der the ther­mal cam­era tells the full story. Af­ter a ten-minute, all-cores bench­mark run, the pro­ces­sor cores show up clear as day on the Pi 3 as 100°C hotspots on the plas­tic pack­age, while the rel­a­tively thin PCB heats up only on one side. The Pi 3 B+’s new pack­ag­ing, im­proved bond­ing and thicker PCB – re­sult­ing in a weight gain from 40g to 50g – dis­pense with these hotspots, keep­ing the pack­age tem­per­a­ture well be­low fin­ger­tip-burn­ing lev­els, and bleed­ing off the heat from the en­tire PCB.

That has two fur­ther im­pacts, which are less immediately ob­vi­ous. The first is that, thanks to the heat now be­ing spread more

evenly through­out the die, the on-board tem­per­a­ture sen­sor now re­ports the sys­te­mon-chip (SoC) tem­per­a­ture more ac­cu­rately. Com­par­a­tively, the Pi 3 could hit over 100°C ex­ter­nally while re­port­ing a sub-80°C in­ter­nal tem­per­a­ture. The sec­ond is that ther­mal throt­tling is now more ac­cu­rate and sta­ble.

In real-world terms, this all trans­lates into mea­sur­able gains in burst and sus­tained

per­for­mance. The Pi 3 B+ is the fastest Raspberry Pi I’ve tested by some mar­gin – though far from the fastest sin­gle-board com­puter over­all. A SysBench CPU test shows a 30.04-sec­ond com­ple­tion time in four-thread mode, to the Pi 3’s 34.97 sec­onds and the Pi 2’s 54.55 sec­onds.

Mean­while, mem­ory bench­marks hit 857.96MB/sec read and 632.26MB/sec write, com­pared to the Pi 3’s 719.76MB/sec and 547.9MB/sec re­spec­tively.

It’s the net­work­ing side, though, where the big­gest ad­van­tages can be found. For the first time, the Raspberry Pi is now avail­able with a Gi­ga­bit Eth­er­net con­nec­tion. Sadly, how­ever, it’s still ham­strung by a shared USB 2 chan­nel to the SoC. In real-world terms, this setup re­sults in a ‘Gi­ga­bit’ con­nec­tion that maxes out around the 212.9Mb/sec mark, a dis­ap­point­ment for all but the folks who have strug­gled with the 89Mb/sec peak of the older mod­els. There’s even sup­port for Power over Eth­er­net (PoE), although it re­quires the pur­chase of an op­tional add-on HAT.

Wi-Fi, too, is im­proved. The chip an­tenna of the Pi 3 has been ditched in favour of the same ground-plane an­tenna de­sign used for

the Pi Zero W, and it of­fers a slight but re­li­able im­prove­ment in sig­nal qual­ity. The ra­dio it­self now sup­ports both 2.4GHz and 5GHz op­er­a­tion, a first for the Raspberry Pi fam­ily, and it’s re­ceived an up­grade to Blue­tooth 4.2 as well as the lat­est Blue­tooth Low En­ergy (BLE) spec­i­fi­ca­tion.

Per­haps the what’s most sig­nif­i­cant about the Pi 3 B+, though, is how lit­tle has changed. The board lay­out, bar the new PoE header, matches its pre­de­ces­sors ex­actly, and is

com­pat­i­ble with all ac­ces­sories. On the soft­ware front, it’s still pos­si­ble to burn the lat­est Rasp­bian op­er­at­ing sys­tem to a mi­croSD card and in­sert it into any Pi, from the orig­i­nal launch model with its sin­gle-core BCM2835 and 256MB of RAM, right up to the new Pi 3, and have it op­er­ate per­fectly.

Sadly, that also means many of the is­sues with the stan­dard Pi de­sign are still present: the 3.5mm AV jack’s qual­ity is still poor, there’s that sin­gle USB 2 chan­nel to the SoC for the Eth­er­net and USB ports, no 4K video sup­port, just 1GB of RAM and no high-speed con­nec­tions for pe­riph­er­als.

That said, when this board has an ask­ing price of just £32 inc VAT from sup­pli­ers, in­clud­ing https://shop.pi­moroni.com (but not in­clud­ing a few un­named chancers who hiked the price as high as £36), these is­sues pale into in­signif­i­cance.

The Raspberry Pi fam­ily re­mains the best­sup­ported pocket-money mi­cro­com­puter fam­ily, and the Pi 3 B+ is a wor­thy suc­ces­sor to the rather flawed Pi 3 de­sign.

The Raspberry Pi 3 Model B+ isn’t a Pi 4, but it’s still a wor­thy up­grade from the Pi 3

A new, smarter PMIC chip means a sim­pli­fi­ca­tion to the board lay­out and a re­duc­tion in the over­all com­po­nent count

A Power-over-Eth­er­net (PoE) header is a wel­come ad­di­tion, but needs add-on hard­ware to op­er­ate

Ther­mal imag­ing shows the sig­nif­i­cant im­pact of the new de­sign on heat dis­si­pa­tion

The new Eth­er­net and USB con­troller pro­vides a Gi­ga­bit Eth­er­net con­nec­tion, but sadly not Gi­ga­bit through­puts

New pack­ag­ing and bond­ing has im­proved the ther­mal char­ac­ter­is­tics of the BCM2837 SoC con­sid­er­ably

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