I was one of the lucky ones who received a Raspberry Pi 4 Model B in the 10th Birthday Celebration.

What I wrote back then was:

Pi4 - The Window on the World

When they designed the Raspberry Pi 4 Model B, they read my mind about what new features I would like to see in a Raspberry Pi. The reason I had this feature list in my mind was I wanted to build a full desktop computer to learn Linux with and then explore setting it up for useful workflows and applications. The location for this computer would be in my basement workshop, which is where I build electronics and do video blogging. I am not looking to replace my high-end PC (located upstairs) which I use for CAD and video editing and I'm not looking to create a powerful gaming machine, I just need to use it for workshop tasks like  Libre Office, email, browsing electronics data, maybe watch some YouTube, display schematics and PCB layouts, use a paint program and maybe some arduino programming. I would hook it up to a fairly large 4K TV which would allow the system to give the basement a little more atmosphere when it wasn't busy displaying data. This would be done by displaying beautiful UHD panoramic scenes from around the world as if that was the scene just outside - the Window on the World. (a bit like what therepairatrooper did with his project)

I see this computer as a low-cost, light-weight workhorse connected to a huge display that runs a lot of hours doing lots of useful things that aren't a good fit for a big power-hungry PC. I do a lot of electronics projects and I expect as I become more familiar with these new Raspberry Pi's, I will start using them in more projects.

This computer would no doubt be featured in several blogs as I work it into various workflows. Initially to maximize its life I would pay close attention to packaging, particularly thermal performance. The packaging and thermal setup would likely be the subject of a blog all by itself.

I am very keen to explore how to make Raspbian useful for many of my hobby activities and it is very exciting to see that the new Raspberry Pi has the capability to handle a very useful complement of the tasks I have in mind.

The Review

It has been a real struggle to make some time to exercise this latest Raspberry Pi, but I need to at least publish what I have done so far:

After collecting some material to do thermal testing, I have put the system together and run some tests. I was looking for the best cooling system I could find, that would work in my environment, and this is what I came up with:

I will be comparing this active heat sink with a passive one I purchased for a Raspberry Pi 3B+.

The passive heat sink is very nicely designed and it fits the Pi 3 perfectly.

The Pi 4 heat sink uses one panel from the Pi  3 design which doesn't do much because it doesn't contact any hot components and the other panel contacts only one chip and misses the other one.

To rectify these issues I added thicker thermal pads - it is hard to find thermal pads of specific thicknesses for a pre-machined parts.

I tested the heat sinks in various orientations to see which performed better. I did not run these devices without heatsinks as it is well known that these devices will throttle performance when their temperature exceeds 80 ° C and the stress test I run will cause this condition.

In these tests I run the temperature high and then let it settle down to a steady state, so if anything, the temperatures listed are slightly higher than if the test was left to run longer.

I measured the temperature of the top heat sink, the bottom heatsink and the internal chip temperature. In the case of the Pi4, I measured both with the fan running and with it not running.

The temperatures were measured at idle and during running a standard stress test. I also measured the current consumed at idle and during stress testing.

Power Consumption

TestPi 3B+Pi 4B (no fan)Pi 4B (fan on)
idle0.43A (2.2W)0.58A (2.96W)0.71A (3.62W)
stress test0.96A (4.9W)1.06A (5.4W)1.15A (5.87W)

 

Temperature ( ° C)

TestPi 3B+Pi 3B+Pi 4B (fan off)Pi 4B (fan off)Pi 4B (fan on)
Idle Internal T4240474538
Idle Top T3635393831
Idle Bottom T3434413834
Stressed Internal T6059676552
Stressed Top T4847534635
Stressed Bottom T4444525140
Orientation

horizontal

Vertical

horizontal

Vertical

horizontal

These heatsinks work very well, in all cases the internal temperature is well below the throttling temperature, and the heatsink temperature is not too hot to touch.

I am a bit surprised that the bottom heatsink is so hot and that the vertical orientation doesn't make much difference.

I really like that the fans on the Pi 4 keep the internal temperature below 55 degrees.

One other note about the fans - they are virtually silent - I can't hear them at all in my computer room.

Running a Stress Test

The stress test is run using:

sudo apt-get install stress

sudo stress --cpu 4

watch -n 1 /opt/vc/bin/vcgencmd measure_temp

 

4K Video (note - this section will be edited as I discover how to get things working)

The next test I wanted to do is high resolution display.

I hooked up the Pi 4B to a large UHDTV to see how it looked - and it looks great.

Next I captured some 4K MP4 video with my camera and tried to play it on the Pi 4B - this did not work (so far). The VLC player on the Pi just shows blank. So I used a video converter to convert from MP4 to MP4 with the same 4K resolution. VLC displays this file, but the video is frozen on the first frame. VLC on my PC plays these files well, so it would seem we need to wait for a VLC upgrade for this to work.

Next I tried to play 4K YouTube videos with the browser - this worked.

The still image viewer also displayed 4K resolution stills.

In both cases the results look good, but I can't tell if it is displaying full 4K resolution. Between the TV performance, the camera performance and the Pi performance, it is tough to tell where the image is being degraded and there are so many pixels, it is tough to tell if there is any degradation at all.

Here is a screen shot, which doesn't do the system justice, since I can't put a full resolution image in this blog and the camera lighting was not good to start with.

Here is VLC trying to play a 4K video, but only showing the first frame:

I am still trying to get audio to be included in the HDMI signal and find a way to play 4K videos from my camera.

So far the Pi 4B is definitely snappier that the Pi 3B+, and is quite usable, but I haven't decided if it is better to run two 1080p monitors or a 4K TV.

Since this is going to be my Linux learning system, I am leaning a bit towards dual monitors so I can keep one with a search engine focused on Linux info.

The big TV may have to wait for a better player app and my second Pi 4.

  • I set the desktop to 4K resolution by editing the config.txt file in the boot directory. This is the only directory visible to in Windows, (when the SD card is inserted in a PC) so it can be edited either by the Pi or a PC.
  • When displaying 4K resolution, my UHDTV (which is supposed to display full 4K video) does not display fine text well. This makes the 4K resolution mode pretty useless for any application involving text - until I get a better monitor. This particular TV has various cinematic modes but none of them make every pixel clear. The TV is readable enough to use it to select images and video, so it could be used as a nice media viewer with this TV, just not for general computing tasks.

While trying to get the desktop to display in 4K resolution, I changed a display setting that completely hangs the system during boot. I got around this by editing the config.txt file on a PC.

This shot is a 4K test pattern to see if the TV can display every pixel of a 4K image.

Note that it displays 2 pixel lines okay, but single pixel lines show aliasing artifacts. You will need to expand the image to see it clearly.

I think I might put this system in a little box so if and when I go shopping for a TV or monitor, I will be able to see how good the resolution really is.

It might even make a good product as dedicated test pattern generators can cost between $1000 and $5000.

The next crop is just a small corner of the display to show how small text is readable, but not high quality on this TV:

When I set it back to 1080p I will be trying some of the apps like LibreOffice.

 

Relevant Links:

Win a Raspberry Pi 4 in Celebration of Our 10th Birthday!

RoadTest the Raspberry Pi 4 Model B (2GB)