Raspberry Pi 3B+ temperatures


#1

A bit off the topic, but with the heatsink(s) on your 3B+, what is the temperature reported on your PiHole dashboard? I don’t run heatsinks on mine, all it runs is PiHole and unbound, and it’s usually at 125F (just a bit less than 53C). My 3B+ is in one of the AdaFruit plastic cases, closed on all sides.


Load Blacklist from network drive, set QueryLog to "ALL"
#2


But my Raspberry Pi case also has a small fan built-in.


#3

Hey,

My pi2 is aprox. 45~46° tempPI2
My pi3B+ is aprox. 55~57°
They are both in a original raspberry pi case, no heatsinks or fan.


#4

My standby PiHole is on a Zero WH in an Adafruit plastic case. Without much DNS load on it (the load goes to the primary), its running 39 C.


#5

What case is that with the fan? That’s pretty nice.


#6

I have 2 Pi-Holes, primary and secondary DNS for my home network of about 40+ devices.

They are running at 53 and 48 degrees celsius respectively.


#7

@jfb I got it from AliExpress - was €2.99 including fan and shipping to Germany. Fan is very silent.


#8

The Raspberry Pi 3 B+ is expected to have higher temperatures. If you pay close attention, you can see that the B+ even has an inbuilt heat-sink (although it may not look like one due to the missing cooling “fingers”)

3Bplus

This metal plate is the most primitive form of a heat-sink and glued on top of the CPU (below is the RPi 3 B v2 CPU)

3B

My 3B+ offers only a little bit of additional performance (few percents) but needs about 20% more electrical power. As this additional power consumption has to go somewhere (after all energy is conserved in closed systems :wink: ), the device gets much hotter and this is expected.

I stored my 3 B+ in the cabinet and happily use 3 B (not plus) for everything and am very satisfied.


#9

On of the reasons I got a regular 3B instead of the plus.

@jfb , check if your patched as it might have influence:

pi@pi-hole:~ $ vcgencmd get_config int
sdram_freq=450

#10

Yeah, I got it in one of the very first Pi-supply kits I ordered. After having had many issues with this hardware, we asked them to ship Pi 3B for now. (Warning: personal opinion following) I think the Pi 3B is a much better device and should be preferred in all cases. The additional power consumption of the B+ is not justified for the few percent of extra performance you get. Also, as the difference is really minimal, there is nothing that only the 3B+ could do.


#11

Okay, since we do not want to speculate but only want to judge based on facts, I did some measurements. In order to make them fair, I did a few things:

  1. Updated both my Pi 3B and Pi 3B+ to the most up-to-date version of Raspbian (newest kernel, etc.) + rebooted
  2. Ensure that both only run Pi-hole and verified that they have about the same load
  3. Let them sit for two hours like this
  4. Made some thermo images I attach below

Both are connected to a Gigabit Ethernet switch and have WiFi/Bluetooth disabled. They use identical power supplies (5V/2.5A).

Raspberry Pi 3B:

Raspberry Pi 3B+:

Raspberry Pi 3B Ethernet chip:

Raspberry Pi 3B+ Ethernet chip:

Raspberry Pi 3B CPU:

Raspberry Pi 3B+ CPU:

Note: I put an opaque sticker on the CPUs to ensure that the temperature measurements can be compared (as the metal cover of the Pi 3B+ has a different reflectivity, this would have otherwise made the comparison quite difficult).

Interestingly the hottest points are, for both, always the Ethernet chips whereas the 3B+ chip got much hotter than the 3B chip (57.0°C vs. 44.0°C). Both CPUs hover at about the same surface temperature (~41°C).

They both report meaningful temperatures (3B 42°C, 3B+ 44°C) using /opt/vc/bin/vcgencmd measure_temp.

This test was under idle conditions and I may repeat them under load (with a suitable benchmark) at some point, but this makes me conclude that the Raspberry Pi foundation apparently managed to resolve the previously seen temperature issues with their recent patches.


#12

I repeated the test under full load. Used benchmarking command was seven times

sysbench --test=cpu --cpu-max-prime=20000 --num-threads=4 run

Top is the Raspberry Pi 3B, bottom 3B+

Peak temperatures and reported temperature (vcgencmd measure_temp):

  • 3B: 99.5°C (intern: 81.7°C +/- 1.0°C)
  • 3B+: 72.5°C (intern: 70.9°C +/- 1.0°C)

The actual run time of the benchmark test (computing prime numbers on all four cores) was

  • 3B: 15m35.045s +/- 5 seconds
  • 3B+: 10m24.120s +/- 2 seconds

I ran the benchmarks three times to estimate the scatter in time. It is surprisingly small.
To make the comparison a bit more fair, I compute the average surface temperature of the opaque sticker on the CPUs:

Raspberry Pi B3: Averaged temperature in the rectangle: 71°C

Raspberry Pi B3+: Averaged temperature in the rectangle: 70°C

We see that both CPUs are about equally hot whereas the heat-sink clearly helps in spreading the heat across the entire available chip surface.

So where does the extra power the Raspberry Pi 3B+ consumes go to?
You may be able to guess it from the first picture (comparison of the two boards). I also computed the average surface temperatures for the entire boards and see that it’s about 50°C for the Raspberry Pi 3 and about 55°C for the Raspberry Pi 3B+.
The PCB clearly helps radiating the heat.

After all, I think it’s fair to say that the Pi 3B+ is - including all patches as of June 23, 2018 - a fair device:

  • Yes, it runs hotter,
  • Yes, it consumes more power, but also:
  • Yes, it also gives a notable improvement in computational performance (at least for computing prime numbers).

This benchmark was for multi-core performance. Single-core performance tests show similar differences between the two board, whereas the maximum temperatures are much lower (65°C for Pi 3B, 55°C for Pi 3B+).

Note: Obviously you don’t want to use a Raspberry Pi for computing primes as the same task is completed in about 30 seconds on a regular PC that is already five years old (Intel Xeon E3-1245 v3). Getting the same task completed about 20x slower at about 5 Watt power consumption makes the “dollars per computation” close to being identical between the two devices.


#13

Here’s the output for my 3B+. Does this indicate if it’s patched? (I’m not familiar with the patches). I ran both “sudo apt update” and “sudo apt upgrade” a few days ago, so I should have the latest. Raspbian Stretch.

pi@Pi-3B:~ $ vcgencmd get_config int
aphy_params_current=819
arm_freq=1400
audio_pwm_mode=514
config_hdmi_boost=5
core_freq=400
desired_osc_freq=0x33e140
desired_osc_freq_boost=0x3c45b0
disable_commandline_tags=2
disable_l2cache=1
display_hdmi_rotate=-1
display_lcd_rotate=-1
dphy_params_current=547
force_eeprom_read=1
force_pwm_open=1
framebuffer_ignore_alpha=1
framebuffer_swap=1
gpu_freq=300
hdmi_force_cec_address=65535
hdmi_force_hotplug=1
hdmi_group=2
hdmi_mode=82
init_uart_clock=0x2dc6c00
lcd_framerate=60
over_voltage_avs=56250
over_voltage_avs_boost=0x27ac4
pause_burst_frames=1
program_serial_random=1
sdram_freq=450

#14

Yes it looks like its patched.
They lowered sdram frequency from 500 to 450MHZ to patch a hardware design flaw.


#15

I run at about 82F. I use an open ventilated case, heat sinks and Noctua Premium fan. Under load it never gets as higher than 107F.