My Thoughts on Using a Raspberry PI 4 8GB as a Desktop Replacement

[nobozo]

Jon Forrest
[mod: removed email address - to stop spammers harvesting it]
8/15/2020

As I’ve gotten older, I’ve become less and less interested in owning the fastest desktop PC in the world. Instead, I’m way more interested in having the quietest PC. This isn’t as easy as you’d think because I’ve also become dependent on having dual 4K monitors on my desk. I haven’t found any inexpensive PCs that can drive dual 4K monitors unless I install a separate graphics card. Doing so works fine but it’s not quiet. I can definitely hear the fans from the PC and the graphics card.

In the past, Raspberry PIs were mainly used for special purposes, such as micro-controllers, monitors, robots, and the like. They weren’t designed to be desktop computers. But now, RP4s with 8GB RAM, USB 3 ports, 2 4K HDMI video ports, and 4 CPU cores at least at first glance look like contenders. I decided to take the plunge, and bought an RP4 8GB.

A number of people have created YouTube videos or blog pages summarizing their experiences in trying to use a Raspberry Pi 4 (RP4) as a replacement for traditional desktop PCs. In general they say that a RP4 is infuriatingly close to being a replacement, but that it has a ways to go. I agree with this, and I thought I’d post my reasons for thinking so.

None of what I say below is original. It’s all been said before. It’s also important to keep in mind that most of these issues only matter when using an RP4 as a desktop replacement. While other uses, and users, of RP4s would benefit if these issues were resolved, they’re not showstoppers. Also, I don’t want to sound unappreciative. The RP4 is an amazing computer for an amazing price.

Here are the major issues I’ve found:

TLS/HTTPS Performance
I’m lucky to have a 1Gbs internet connection at home. This isn’t just the theoretical top speed of my connection. With my regular Windows PC, when going to https://fast.com I regularly see 1Gbs download speed. However, if I move the cable from my PC to my RP4 I “only” get 150Mbs. This is nothing to be ashamed about, but it’s still just 15% of what I get with my regular PC. I did some tests (see viewtopic.php?f=63&t=280994 for the details) and found that ~85% of the network performance is lost when using https on my RP4. As I said in my posting, if I run the iperf3 network testing program between the RP4 and another PC on my 1Gbs local network, I see ~900Mbs. This shows that the ethernet adapter on the RP4 is not the cause of the slow down. My current hypothesis is that the RP4 doesn’t have the necessary hardware instructions to run TLS/HTTPS at full wire speed. For a desktop PC this is a big deal.

Unoptimized Graphics Stack
On my Windows desktop PC I spend (waste?) an amazing amount of time watching YouTube and streaming video services (e.g. Netflix, Amazon, Hulu). Poor graphics performance is one of the recurring themes I see in many of the RP4-as-desktop-replacement videos and postings. This is in spite of the presence of a GPU in a RP4 . I’m not well informed enough to know what the problem is, but it’s clear that the whole graphics stack needs to be optimized and tuned for RP4s. It should be easy for Raspberry Pi OS and every other OS distribution to come with the proper drivers in place so that end-users don’t have to make configuration changes.

32-bit vs. 64-bit Architecture
For traditional RP4 uses, the need for single processes greater than the 3GB limit imposed by the 32-bit architecture was uncommon enough so that moving to the 64-bit architecture wasn’t a big deal. It’s still not crystal clear how necessary processes larger than 3GB are on a desktop replacement. However, given that a desktop replacement needs all the performance it can get, a 64-bit architecture can make a real difference. I know that 64-bit Raspberry Pi OS is in beta mode but I’m hoping that the Raspberry Pi Foundation, and other OS developers, give equal priority to the 32-bit and 64-bit architectures.

MicroSD vs. USB
Relying on a MicroSD card for anything other than booting is asking for trouble. They weren’t designed to be a general purpose I/O device. The fact that they work as well as they do on an RP4 is a miracle. I know that Raspberry Pi OS and the RP4 firmware have recently been updated to allow booting from a USB device. This was great news, but, as of today, only the 32-bit version of Raspberry Pi OS supports this. USB booting should be standard on all RP4 OSs.

Digital Rights Management
This is another area where I’m not well informed. But, I believe that currently the only Web browser on a RP4 that can display Netflix video is Chromium, and even then you have to manually add various libraries and be running 32-bit Raspberry Pi OS. I’m not sure what can be done about this, but anyone thinking of using an RP4 as a desktop should expect some rough sailing here.

For me, these issues I’ve described above are too great to make me want to keep my RP4 so I’ve decided to sell it. Instead, I’m buying a Hardkernel ODROID-H2+ . This is a single board computer with a 4 core Intel Celeron, 2 memory slots supporting up to 32GB, and a NVMe slot. Sure, it’s about twice as expensive as a RP4 but I’m not expecting to have to make as many compromises.

I welcome corrections and comments.

Jon Forrest

[LTolledo]

its good to know that its your thoughts.... and yours only....

[fruitoftheloom]

Digital Rights Management
This is another area where I’m not well informed. But, I believe that currently the only Web browser on a RP4 that can display Netflix video is Chromium, and even then you have to manually add various libraries and be running 32-bit Raspberry Pi OS. I’m not sure what can be done about this, but anyone thinking of using an RP4 as a desktop should expect some rough sailing here.

The Raspberry Pi SBC is not classed as a "Secure Platform" therefore DRM is an issue, unfortunately it is not a *standard* that RPT / RPF have any control over.

[fruitoftheloom]

.
Both ARM64 Raspberry Pi OS and USB Boot are testing stage and I would expect an announcement in the near future...

...in actual fact my 4B 4GB is running well booting from a cheap crappy USB3-SATA Cable / SSD Drive running RaspiOS64.


Personally my ChromeBox and SmartPhone have replaced my Desktop / Laptop.


Life is about choices and opinions

[bassamanator]

@nobozo

I enjoyed reading your critique. You made some valid points but I'm not sure if the Raspberry Pi foundation has made the claim that the RPi4 is a desktop replacement (someone please correct me if I'm wrong). I think that's the goal of the foundation, to produce a single board computer that can replace a desktop computer. I do think, however, that for the budget user they have succeeded. For example, my uncle has two personal computers, one for his wife and one for himself. They are both slower than my RPi4-8gb. For them, the RPi4 would be a good desktop replacement. In my own personal computer I have a CPU with 8 cores/16 threads @ 4.1GHz and other nice specs so I do very little waiting. But you know if I were on a budget, I'd be fine with a RPi4. As they say, beggars can't be choosers. I do think the power supply should be included in the cost of the board and that's about the only gripe I have with the RPi.

Your critique is very helpful by the way and I thank you for it. The Raspberry Pi Foundation needs to hear this kind of stuff so that they can improve their product, fix existing problems, and to produce a better product in the future.

[fruitoftheloom]

@nobozo

I enjoyed reading your critique. You made some valid points but I'm not sure if the Raspberry Pi foundation has made the claim that the RPi4 is a desktop replacement (someone please correct me if I'm wrong). I think that's the goal of the foundation, to produce a single board computer that can replace a desktop computer. I do think, however, that for the budget user they have succeeded. For example, my uncle has two personal computers, one for his wife and one for himself. They are both slower than my RPi4-8gb. For them, the RPi4 would be a good desktop replacement. In my own personal computer I have a CPU with 8 cores/16 threads @ 4.1GHz and other nice specs so I do very little waiting. But you know if I were on a budget, I'd be fine with a RPi4. As they say, beggars can't be choosers. I do think the power supply should be included in the cost of the board and that's about the only gripe I have with the RPi.

Your critique is very helpful by the way and I thank you for it. The Raspberry Pi Foundation needs to hear this kind of stuff so that they can improve their product, fix existing problems, and to produce a better product in the future.

https://www.raspberrypi.org/blog/raspbe ... placement/


If you have followed various Videos / Chats, mainly involving Eben Upton, you will know that the RPT / RPF are aware of limitations, stating otherwise is unfair..


One needs to take a step back and look at the aims and ambitions from 2010 to put into perspective that where RPF / RPT are today is not where they envisaged.


A lot of the issues about how good a Raspberry Pi SBC is, is Bloggers, Reviewers etal not fully understanding but rather want to earn "click bait" advertising revenue.

[Heater]

...I'm not sure if the Raspberry Pi foundation has made the claim that the RPi4 is a desktop replacement...

It says exactly that on the front page of their web site:

Raspberry Pi 4
Your tiny, dual-display, desktop computer

Of course that all depends on ones interpretation of "desktop computer". I don't imagine anyone is dumb enough to think they are getting the likes of a current Intel or AMD monster for that price.

I do think the power supply should be included in the cost of the board and that's about the only gripe I have with the RPi.

I for one am very glad they do not do that.

Almost none of my Pi run from an official PSU and most of them are not even powered by typical wall warts. Having a PSU supplied with each Pi would mean just another thing I have to send to the land fill. Not good.

Also to meet the price target if a PSU were included something else would have to go, perhaps WiFi or bluetooth or memory or whatever. I would be getting a lesser product for my money. Not good.

[clicky]

MicroSD vs. USB
Relying on a MicroSD card for anything other than booting is asking for trouble. They weren’t designed to be a general purpose I/O device. The fact that they work as well as they do on an RP4 is a miracle. I know that Raspberry Pi OS and the RP4 firmware have recently been updated to allow booting from a USB device. This was great news, but, as of today, only the 32-bit version of Raspberry Pi OS supports this. USB booting should be standard on all RP4 OSs.

I am not sure if that claim is correct. My understanding was that (at some point!) only 64bit OS was supporting boot from USB out of box while for 32bit you needed to do some work to achieve it (that's definitively not the case any more).

My Raspberry Pi 4 running 64bit PiOS boots of SSD directly - and I haven't done anything special for that to happen.

Aside of that - I like your calm and precise way to explain what bothers you in RPi (4) as Desktop Computer. Fortunately, I can see most being only software issues and over time they might be fixed one way or another.

My main worry is that many modern software is pushing hardware slightly more than (Raspberry Pi) hardware can achieve. Fortunately not all software - Gimp (one of the CPU + memory bound apps) copes quite well given 1:3 in CPU clock ratios (probably 1:5 or worse if you compare actual CPU speed).

[jamesh]

1. Yes, well known that there is no HW acceleration for crypto. There are improvements when using NEON to accelerate in software. Most people don't see this as a major issue. I'd never even noticed it.
2. Graphics stack. Moving to DRM/KMS is a long winded process and still ongoing. We need to move away from legacy (which worked fine) towards more OSS and standard graphics.
3. 32 vs 64. We have a 64bit distro available for testing. It's not that much faster so don't expect miracles just moving to 64bit.
4. uSD card. Disagree - it's not a miracle that they work - they work fine and have done for 8 years. Or use an SSD, very close to making that very easy.
5. DRM. Nothing to do with us.


Enjoy whatever alternative you chose.

[GlowInTheDark]

Keep in mind that most people's (not most people here on this board, but most people living on planet earth - I hardly need to hear from people on this board saying "Well, I don't need to run Windows!" I know that; you don't need to bother) definition of "Desktop Computer" is one that runs Windows X86 software.

We're still a long way from achieving that.

[bensimmo]

GlowInTheDaek,
Desktop Computer to people I talk to is a computer that sits on the desk (or under), most importantly in their definition is a keyboard and mouse to control it, look at it on a big screen which is probably 19"+ now.

It could be Apple, Windows, Linux, Google, PC, AIO, a box, or whatever, they don't care. Generally they expect to be able to do the day to day stuff with a big screen, email, web, streaming and some lightweight office work.

I guess obviously we have different people around us.

[GlowInTheDark]

Don't think for a second that either the population of this board or your circle of friends are representative of the population as a whole.

[bensimmo]

Don't think for a second that either the population of this board or your circle of friends are representative of the population as a whole.

and you speak for Earth do you?

I believe you have your own definition you think others think.

[jamesh]

For many people a desktop computer is one that runs a browser, because nowadays you can do everything you need from that.

And as we all know, for the most part, browsers are OS agnostic.

My father has a laptop. He probably doesn't even know it's not running Windows.

[Heater]

Conversely, I have been using Win 10 every day for a couple of years now. Having avoided anything proprietary since 1996.

It was quite an eye opener. Having got past the complexity of using Windows I was amazed to find it can run pretty much all the programs, dev tools etc that I have been using on Linux for decades: Chrome, Firefox, Inkscape, Gimp, VLC, Eclipes, InteliJ, Sublime, VS Code, Libre Office etc, etc. Not only that it has the Linux Subsystem for Windows so it runs pretty much all of what I use from Debian, and other distros too.

I was pleased to find that Windows had finally developed in an OS I could use day to day. Sometimes I even forget that it is not a Linux system. Which catches me out when I want to do something that requires a real Linux kernel underneath. I believe MS have a fix for that as well, the WSL2.

Now, about that idea of what most people imagine as a 'desktop computer'. As far as I understand most of the people on this planet don't even use a traditional x86 Windows PC or laptop. So I don't understand all this talk of running x86 software as being critical to anything.

[LTolledo]

So I don't understand all this talk of running x86 software as being critical to anything.

yeah, much like the story of:
....."the frog in the well"......

[Heater]

Cool, I'd heard the thing about boiling frogs but never heard of the "frog in the well" story.

What was the ending? Did the frog get eaten by a cat or something?

[lurk101]

So I don't understand all this talk of running x86 software as being critical to anything.

In my experience people spend the most time using computers at work.

[PeterO]

So I don't understand all this talk of running x86 software as being critical to anything.

In my experience people spend the most time using computers at work.

Not everyone works in an office !
PeterO

[bjtheone]

Hummm... at work, 30% in meetings, 10% with staff, 25% in email or on the phone, 15% in excel, 10% in a browser, 10% drinking coffee.... 0.1% actually doing anything resembling direct interaction with the OS. I actually could do most of my "work" using my phone plugged into a monitor, using Dex, which is what I do when I am travelling on business if I don't want to lug a large laptop.

At home, 80% doing stuff in a browser (reading news, researching, watching Netflix), 20% in other tools, 10% at the command line mucking about. A 4B 8GB with a large monitor is most definitely my main (and only) desktop. All other computers are laptops (more Chromebooks than anything else) , tablets, and other Pis.

For most people, home use revolves around a browser, which is increasingly OS agnostic. I would suspect that "home" use now trumps work use in North America and Europe, with more hours logged on a smartphone that a "traditional" computer.

[gordon77]

So I don't understand all this talk of running x86 software as being critical to anything.

In my experience people spend the most time using computers at work.

Not everyone works in an office !
PeterO

Not everyone works

[GlowInTheDark]

I think this discussion of "work" has even less to do with the original thread topic than the need for Windows or X86 does.

I have no idea where it (the "work" thread, not the x86 thread) came from.

[hippy]

Keep in mind that most people's ... definition of "Desktop Computer" is one that runs Windows X86 software.

More that a "desktop computer" runs what people want to use or need to use in their daily and working lives. So, for some, a desktop computer will have to run X86 software but, for others, not so much.

I have a number of "desktop computers" at home and for work. A Raspberry Pi would be a replacement for some, could be a replacement for others, but couldn't be a replacement for all.

There's no meaningful answer to "Is the Raspberry Pi a replacement for a desktop computer?" unless one creates an artificial or contrived definition of "desktop computer".

The best one can do is categorise the individual cases where users find that a Pi can or cannot be a replacement for their desktop computers.

Is the Raspberry Pi a suitable replacement for some category of desktop computer users ? I would say yes, and it's probably a large group, possibly a majority.

Is it a replacement for all ? No, not at the present time. And it may never be.

[ejolson]

So I don't understand all this talk of running x86 software as being critical to anything.

In my experience people spend the most time using computers at work.

Not everyone works in an office !
PeterO

I think the fact that not everyone works in an office is very important to remember. Without people who build stuff, repair stuff and grow stuff there wouldn't be any wealth created for the office workers to organise with their electronic paperwork. It's also nice the Pi can provide a home computer even a child can afford.

Going back to the original post, it may be a configuration problem that you only get 150 Mbps on an Internet connection that performs at 1 Gbps with other computers. I would expect the speed to drop off more gracefully when https is used to around 700 Mbps. Is it possible flow control is turned off on the router?

Note turning off flow control by default is a trick used by some service providers to deal with high latency connections. In the case the local computer can receive packets at wire speed, the performance will look a little better. In the case that it can't, the performance will fall off a cliff as you have discovered. Have you tried enabling flow control on the router?

From my point of view, your problems with video drivers are difficult to solve; however, the problems with network speed and the 32-bit operating system should be solvable right now.

[W. H. Heydt]

In my experience people spend the most time using computers at work.

Not everyone works in an office !
PeterO

Not everyone works

Some of us are retired.

To the extent that I still work---I run convention registration for an annual gaming con that attracts about 1800 members--it is, at this point, *all* done on Pis. The "back room" is two Pi4B4 systems running from 120GB SSDs (replicated MariaDB database), while the public facing part is run on half a dozen Pi2Bv1.1 systems.

With the sole exception of an on-line game I play (LoTRO), I could replace my home desktop with a Pi4B. So, at least for me, the Pi4B is an almost complete desktop replacement, should I choose to use it that way. For my 12-year-old grandson, a Pi4B2 *is* his desktop computer...and it's all ready and set up for remote school to start tomorrow.