back to article High-resolution display output or Wi-Fi: It seems you can only choose one on Raspberry Pi 4

Users of the Raspberry Pi 4 mini computer are puzzling over an issue where setting some display resolutions have the side-effect of killing the Wi-Fi connection. The problem was noticed by developer Enrico Zini, who is working on a digital signage box using the Raspberry Pi 4. "One full day of crazy debugging, and the result …

  1. JimP
    WTF?

    "Mini computer"? Shall I compare it to a DEC PDP-11?

    I early-adopted the original Pi and I still have it in constant use. I got a Pi 4 on the basis that it's so much faster and with 16 times more RAM it should still be relevant in another 8 years. I wonder if the Pi 8 will get called a mainframe ...

    1. katrinab Silver badge
      Happy

      It is way more powerful than a PDP11.

      1. itzumee

        a PDP11 is a minicomputer

        1. herman Silver badge

          A PDP11 was a 16 bit mini computer, about equal to a an 80286 based desktop PC of the 1980s. So, yes, an RPi is more powerful computing wise.

      2. Thoguht Silver badge

        OK, so the PDP-11 was a minicomputer, so what? Although it's difficult to compare things from such different eras exactly, if you're using the SPEC benchmarks then the Pi 4 should come out between 10-30 times as fast as a PDP-11 on integer operations and at least 30 times as fast on floating point, and that's even assuming the PDP-11 in question had the optional (and expensive) floating point board installed.

        1. Anonymous Coward
          Anonymous Coward

          I think the point that the posters above were perhaps trying to make is that 'minicomputer' has a long-established meaning in the IT industry, and so we should avoid using the term to refer to hardware like the Raspberry Pi, even if it is miniature.

          1. Yet Another Anonymous coward Silver badge

            >'minicomputer' has a long-established meaning in the IT industry,

            Computer has an even older established meaning - It means a person that performs calculations.

            Perhaps we should reserve the original term "computer mecanique" for these gadgets

            1. joeldillon

              If we're going to be all French about it, the term is ordinateur (and, I believe, doesn't have the previous assocation of meaning a human who calculates things).

            2. James 139

              > Computer has an even older established meaning - It means a person that performs calculations.

              Performs computations, not calculations, that would be a Calculator.

              And, being more specific, also a male person, a female being a Computress.

              1. Stoneshop Silver badge
                Headmaster

                Computer, computress

                So an electronic computing device should be called a Computron.

              2. defiler Silver badge

                I like the idea of calling my PC a computress. Just saying.

          2. Anonymous Coward
            Anonymous Coward

            Meanings change. Minicomputers of old were neither mini nor fast by today's standards. Same with MHz frequencies deemed "ultra-high". Context is king. Insisting on old nomenclature isn't going to change anything.

            1. Fred Goldstein

              Microsoft got its name because they made software for microcomputers, those being smaller than minicomputers. And microcomputers are what we call desktops, laptops, or small servers these days. So a pi is more of a nanocomputer. There is no reason to promote it to minicomputer unless you come up with some sense switches for it.

          3. Dave559

            Minicomputer

            I guess the problem is that, at some point, society started informally referring to microcomputers (ZX Spectrum, BBC Micro (obv.), etc) just as "computers", and so, in comparison to them, the RPi would be a mini-computer. The sliding scale moved.

            Should we maybe really call the RPi a nanocomputer instead? But, then, what would be inside nanobots? As an even smaller scale factor, would they have picocomputers inside, or maybe be described as picobots instead? Now my head hurts...

            (aside: are there actually (m)any minicomputers still in use, or have they all been replaced by clusters and the like?)

            1. Wicked Witch

              Re: Minicomputer

              I suppose those computers running 500W CPUs would be minicomputers, compared to workstations and supercomputers, but then what's a computer?

        2. Dwarf Silver badge

          Memory persistance

          Who can still remember the toggle switch positions to bootstrap them from the front panel ?

          1. Anonymous Coward
            Anonymous Coward

            @Dwarf - Re: Memory persistance

            I can. Beautiful machine, those were the days!

            1. Tom 7 Silver badge

              Re: @Dwarf - Memory persistance

              Having spent 2 1/2 years walking into our Uni computer room to mostly see it illuminated with 'HARDWARE FAULT' I was given access to a PDP11/20 IIRC and some FORTRAN and if I hadn't spent a few years booting other machines with similar switches I might just be able to. Even writing this I have the memory of the smell of the manuals.

        3. MacroRodent Silver badge

          Emulation speed?

          I wonder if the Pi 4 would beat a real PDP-11 in running exactly the same binary code, with Pi 4 running it in an emulator? Probably yes, if the emulator is written carefully. All 8 PDP-11 registers can be kept in the ARM registers, because it has more of them. The whole 64K address space of a PDP-11 process would fit into the cache of a modern processor.

          1. Grouchy Bloke
            Thumb Up

            Re: Emulation speed?

            Find out - build your own..

            https://obsolescence.wixsite.com/obsolescence/pidp-11

            1. DrBobK

              Re: Emulation speed?

              I learned C on an 11/03 that I was given in the early 1980's - great computer.

          2. katrinab Silver badge

            Re: Emulation speed?

            I think yes, it would completely blow the socks of a PDP11, even if you wrote the emulator in LibreOffice macros.

          3. juice Silver badge

            Re: Emulation speed?

            I did dig this out...

            https://wfjm.github.io/home/w11/impl/performance.html

            If I'm reading it right, an ASIC implementation of a PDP11 clocks in at about 50 times faster than the original hardware. And a 3ghz Intel Core 2 Duo clocks at around the same.

            Meanwhile, a Pi2 clocks in at about 25% of the ASIC implementation, while the Pi3 boosts this up to about 40%.

            So I'd guess that the Pi4, with it's slightly higher clock speed, could maybe hit 50% of the ASIC's speed. Which works out at about 25 times faster than a PDP11...

            1. Anonymous Coward
              Anonymous Coward

              Re: Emulation speed?

              "about 25 times faster than a PDP11..."

              When making that kind of comparison, it might sometimes be useful to specify what kind (or what era) of PDP11 is being referenced.

              There was a bit of a performance difference between first generation PDP11 and final versions.

              Come to think of it, the same may apply to other processor families too.

          4. Fred Goldstein

            Re: Emulation speed?

            I still have a PDP-11/03 based machine in storage. Its power supply capacitors have not lasted 40 years so ti won't run any more without some hardware repair. But with its two 8" floppies and 60 KB RAM it was a reasonably fun machine in its day.

        4. Degenerate Scumbag

          >10-30 times as fast

          You're missing some orders of magnitude there.

      3. Tom 7 Silver badge

        Even the zero pisses on a PDP11

        I will see how many I can SIMH on it when I have a proper mo.

        1. Paul Barnett

          Re: Even the zero pisses on a PDP11

          Someone has done a pdp-11 front panel for a pi running simh - it looks good to me: https://obsolescence.wixsite.com/obsolescence/pidp-11

    2. FrogsAndChips Silver badge
      Coat

      Re: with 16 times more RAM it should still be relevant in another 8 years

      640K should be enough for anyone.

    3. Displacement Activity
      Meh

      "mini computer" != "minicomputer"

      <pedantic-nerd-mode>

      I've still got my copy of Mick and Brick, which was the bible of bit-slice (and mini) design. On p259 a '16-bit time-sharing CPU' is described as the heart of a 'minicomputer'. Even more bizarrely, I've still got the handbook for the Varian 72, which I used in an early job, published in March 74. It describes itself as a 'minicomputer'.

      OTOH, a 'mini computer' is just a miniature computer.

      In more recent news, I'm just about to get a Pi Zero...

      </pedantic-nerd-mode>

    4. Robert Baker
      Joke

      >Shall I compare it to a DEC PDP-11?

      It is more lovely and more temperate?

    5. vaporland

      you can emulate a PDP11 with a Pi

      there's a simulator SIMH that will virtualize it in the Pi.

      https://www.raspberrypi.org/forums/viewtopic.php?t=163320

      I have the HP2000 Time-Shared BASIC OS (circa 1974) working in SIMH on Intel (Mac, Windows, Linux) and I am hoping to get this running on the Pi as well.

      Next goal is to connect the Pi to a real teletype machine so that I can play the text based games of my youth as nature intended.

      $STTR1 and $BLJACK!

    6. Anonymous Coward
      Anonymous Coward

      We had two of them in the olden days, Motorola based, washing machine size with a top loading tapedrive and a ram expansion (2MB iirc)

    7. ElectricPics

      The Pi 4 is already way ahead of the ICL2966 of my yoof!

  2. Dwarf Silver badge

    Interference

    I wonder what the frequency spectrum of an HDMI interface that that resolution looks like compared to a standard 2.4GHz WiFi signal.

    I bet there is overlap and that is the root cause.

    Is it time for Pi's to start coming in cans - RF shielded cans covering their sensitive bits that shouldn't radiate, hence ensuring the bits that should radiate can continue to do so.

    1. TKW

      Re: Interference

      Welcome to the black art of RF design & debugging :/

    2. bpfh Silver badge
      Thumb Up

      Re: Interference

      Seems that cheap HDMI cables & digital interference are a known issue after a quick google search, but more like the interference from outside causes problems inside, with shutdowns initiated in HDMI connected hardware when external events happen like a fridge turning on, or approaching a mobile phone to the cable

      https://superuser.com/questions/428720/hdmi-cable-interference

      Seems the guy's problems were caused by an unshielded cable, possibly with fake ferrites, and replacing with a shielded grounded cable solved the issue.

      Other than that, could an external wifi antenna be added and shifted away from the hdmi ports?

      1. Swiss Anton
        Trollface

        Re: Interference

        Have you tried using a HDMI cable with gold plated connectors?

        1. Blofeld's Cat
          Trollface

          Re: Interference

          And oxygen-free copper cables?

          1. herman Silver badge

            Re: Interference

            I know you jest, but oxidized copper wire can result in complex crystals known as black death, which causes electrical noise in a wire. This was a real problem in the good old bad old POTS days. So the oxygen free audiophile cables is a good example of a complex chemistry effect, distorted and amplified for an audiophile sales pitch.

            1. Tom 7 Silver badge

              Re: Interference

              And gold can cause a thing called the purple plague - well if you dont put some Ti on the silicon before sticking gold connectors on it.

              1. 1752
                Coat

                Re: Interference

                Is that what the artist formally known as Prince was singing about?

            2. whitepines Silver badge

              Re: Interference

              I know you jest, but oxidized copper wire can result in complex crystals known as black death

              I hadn't heard of this one before...got any links? Sounds like old school telephone stuff which I have a bit of interest in myself -- still have to figure out pulse dialing on a modern PBX sometime...

              1. AndyD 8-)&#8377;

                Re: Interference

                <q>I know you jest, but oxidized copper wire can result in complex crystals known as black death

                I hadn't heard of this one before...got any links? Sounds like old school telephone stuff which I have a bit of interest in myself --</q>

                ... and as anyone who has 'inadvertently' re-routed their POTS connection will know, it's carried (for miles) on copper-plated steel wires.

            3. Mage Silver badge

              Re: Interference

              But all electrical wiring has always been manufactured "oxygen free", or else it's brittle. Black copper oxides on the surface is a deployment issue.

              It's STILL a problem if using CAT5 or coax outdoors that doesn't have proper waterproofed covering or joints.

    3. Brewster's Angle Grinder Silver badge

      Re: Interference

      If I'm understanding the spec correctly, HDMI <= 1.4 has signalling rates of up to 1.6GHz; HDMI <= 2 has signal rates of up to 6 GHz; and HDMI 2.1 heads off into the near infra-red. But I'd suspect the cable before the board - maybe wrap it in foil?

      Somebody suggested the foil should be grounded. But I wouldn't have thought it necessary as we're trying to attenuate an outgoing signal rather than shield a cable. The skin depth of a >2GHz signal in aluminium is <2μm so, theoretically, 0.1mm of aluminium should reduce it by a factor of at least 1E-22. Although I guess ungrounded foil might generate unhelpful inference in the cable itself.

    4. Suricou Raven Silver badge

      Re: Interference

      Cans are pricy. The Pi is built to the tightest possible budget (it has to be cheap enough that schools can accept students smashing a few in boredom), so compromises are made.

  3. Timmy B Silver badge

    That explains it....

    Not on a Pi, but... I just started using HDMI on my laptop after a work monitor upgrade. My wireless mouse started to behave oddly - juddering and stuttering. I swapped the mouse dongle to the other side of my laptop and it all works fine. The original side has the USB right next to the HDMI. It does seem that something is interfering with 2.4 and HDMI generally and having the ports all close together (as they are on a Pi) will make it obvious.

    1. Stoneshop Silver badge

      Re: That explains it....

      It does seem that something is interfering with 2.4 and HDMI generally and having the ports all close together (as they are on a Pi) will make it obvious.

      Which also explains the advice to use proper uHDMI-HDMI cables instead of adapters: cheapie adapters may well have insufficient shielding, if at all.

  4. Anonymous Coward
    Anonymous Coward

    The RPi 4 is a complete fail

    From non-standard USB circuitry to borked wi-fi/HDMI, seems the RPi 4 is best avoided altogether.

    1. msage

      Re: The RPi 4 is a complete fail

      You mean other than the fact it works for the vast majority of users? I haven't got a problem with any of my 3 Pi 4's which are in daily use since I got them... They are doing a mixture of tasks, none of them have had any issues (wifi / hdmi or usb power)

      1. Chemist

        Re: The RPi 4 is a complete fail

        "none of them have had any issues"

        Ditto ! Mind mine is in a rather nice cast-aluminium case/heatsink with a genuine hdmi cable.Very impressed fast enough for most (simple) desktop tasks. I've even video edited (1080p50) with mine & transcoded with ffmpeg (all cores working and temp ~65C.

      2. Anonymous Coward
        Anonymous Coward

        Re: The RPi 4 is a complete fail

        It can't hurt to be aware of the problems. They don' t have to apply to your specific use case.

        Then again got some problems with a Pi 1 but that turned out to be a power supply issue.

        The WiFi of my Pi 3 is a bit troublesome at the moment, it used to work better. Could be nasty neighbors WiFi which comes in louder and hogging more channels than my own. Connected an Ethernet cable and hiccups over ssh disappeared.

    2. Anonymous Coward
      Anonymous Coward

      Re: The RPi 4 is a complete fail

      How's life at Ardunio then?

      1. elaar

        Re: The RPi 4 is a complete fail

        To be fair, Arduinos and Rpi's are very different things.

      2. Anonymous Coward
        Anonymous Coward

        Re: The RPi 4 is a complete fail

        > How's life at Ardunio then?

        Do you know the difference between a microprocessor and a microcontroller?

      3. beast666

        Re: The RPi 4 is a complete fail

        Very low power consumption thanks!

    3. werdsmith Silver badge

      The RPi 4 is a complete Success

      Many makers of electronic gizmos looks longingly that RPI 4 sales figures.

      It has a WiFi problem that is not unusual. The USB isn't really a problem, easily worked round. You didn't mention the high temperatures that are much better now the firmware has been fettled.

      It's not as if they are catching fire on aircraft or anything.

  5. mtp
    Mushroom

    HDMI cables are often a issue

    I have EMC tested quite a few HDMI monitors and the emissions from a poor cable can be terrible. Easily 10-20 dB over the limits for a heavy industrial machine. Ferrites and such like don't help much at these frequencies so it has to be a well made cable with full 360 shielding end to end with good coupling to the connectors.

    1. Yet Another Anonymous coward Silver badge

      Re: HDMI cables are often a issue

      The only thing worse than HDMI cables is HDMI connectors

  6. Must contain letters

    and this is why

    these useful toys are not to be confused with dedicated quality digital signage players ....

    1. James Hughes 1

      Re: and this is why

      If you look inside those professional digital signage players, guess what you will find....

      1. Martin an gof Silver badge

        Re: and this is why

        Because you were too shy, here's a link.

        NEC Raspberry Pi Compute module

        M.

        1. Lee D Silver badge

          Re: and this is why

          nComputing N300 thin clients are all Raspberry Pi's nowadays.

          They used to be a custom embedded device, now they're just overpriced RPi's running rdesktop with some vague "licensing" thing on top that you have to pay for the software.

    2. karlkarl Bronze badge

      Re: and this is why

      Same could be said for x86. Great for "Personal Computers" and yet they now pretty much run everything apart from ironically the most personal of digital things (a phone).

      1. Mage Silver badge

        Re: x86. Great for "Personal Computers" and yet they now pretty much run everything

        Um, now pretty much ONLY laptops/PC and Servers.

        TVs, Disc players, phones, tablets, modems, routers, switches, washing machines, microwave ovens, IOT garbage, embedded SATA controllers (Mobo end or HDD end) etc are rarely ever x86 or x86-64: Too expensive and too power hungry.

  7. DCFusor Silver badge
    Holmes

    EMI, not just pi

    Here we've had EMI issues between 2.4 ghz keyboard/mouse dongles and USB3 use, and not just with pi, but also with Intel NUC machines. Seems that some USB cables leak enough signal in the 2.4 ghz spectrum to mess them up. Sometimes changing the cable helps, but unplugging anything USB3 always fixes it.

    We've also found that a cheap passive USB2 hub used between a USB3 port and any USB2 peripherals that would otherwise be plugged into a USB3 socket and run in back compatibility mode reduces various errors.

    Note that in experience here, the little dongles fail far more often than "real" wifi, presumably because the real wifi will do retries.

    It would be nice if someone with a spectrum analyzer would run a pass over this issue and reduce the "black art" aspect.

    You can probably pass FCC regs and still have the problem, as the interference levels the regs are worried about are for devices a good bit further away than an inch or so.

    1. Nathanial Wapcaplet

      Re: EMI, not just pi

      A common-mode ferrite clamp on the cable an inch or two down the line from the USB connector can help too. It's not awlays the screening leakage - common mode currents can be a problem just as much as data lines or RF on the power rail.

      Be aware that many clip on clamps, while having significant attenuation to common-mode RF on the outer braid, can nip the cable so much as to cause damage. I prefer to manipulate the "lips" at either end of the clamp slightly outwards to ensure that they splay out a little rather than dig in too much. If they slide use a dab of hot glue.

      Like many things EMC, it's not a panacea. Nor is it a pancake either. Alas.

      1. Stoneshop Silver badge
        Headmaster

        Re: EMI, not just pi

        Like many things EMC, it's not a panacea. Nor is it a pancake either. Alas.

        Panopticon then? Paneer? Panaflex?

        1. Will Godfrey Silver badge
          Happy

          Re: EMI, not just pi

          Panasonic?

          1. KittenHuffer Silver badge

            Re: EMI, not just pi

            Pan Galactic Gargle Blaster?

      2. Aussie Doc

        Re: EMI, not just pi

        Panadol?

  8. Anonymous Coward
    Anonymous Coward

    Why is this news?

    Electronics user uses crap HDMI cable and/or crap adapter or both, then finds it interferes with stuff. Either get a decent cable with actual shielding, or move to 5G, or both. Simples.

    1. Yet Another Anonymous coward Silver badge

      Re: Why is this news?

      Because it fills the el'reg mandate to entertain, inform and piss of to the pub by 1pm

      If I get bad video I suspect the crappy HDMI cable

      If wifi failed - I wouldn't immediately think to start debugging by dropping the display resolution

      1. Anonymous Coward
        Anonymous Coward

        Re: Why is this news?

        > If wifi failed - I wouldn't immediately think to start debugging by dropping the display resolution

        But from now on I will.

        I bet this will impress the ladies other nerds in the office.

    2. Stoneshop Silver badge
      FAIL

      Re: Why is this news?

      or move to 5G,

      You're not going to find that onboard a Pi 4

      1. Dvon of Edzore

        Re: Why is this news?

        Incorrect.

        Raspberry Pi 4 specifications

        Please scroll down to the line that reads: "2.4 GHz and 5.0 GHz IEEE 802.11ac wireless, Bluetooth 5.0, BLE"

        1. tin 2

          Re: Why is this news?

          Aha. 5G meant 5GHz but taken to mean "5G" and then re-interpreted to mean 5GHz. Not confusing at all. Cheers Marketeers!!!

        2. Stoneshop Silver badge
          Headmaster

          Re: Why is this news?

          '5G' .nes. '5GHz'.

          The Pi4 DOES have WiFi using the 5GHz band (as well as the 2.4GHz band). It does NOT have 5G.

          1. Anonymous Coward
            Anonymous Coward

            Re: Why is this news?

            > It does NOT have 5G.

            It does if you strap it onto a rocket, as I'm sure has been done already.

            1. Aussie Doc
              Trollface

              Re: Why is this news?

              Would be something to 'smile' about, no doubt. --->

  9. Dan 55 Silver badge
    Paris Hilton

    Wait for the next hardware iteration

    How will we know when the RPi 4 rev 1.1 (or whatever) has come out and when ordering we will be sure to get one instead of the last rev 1.0s (or whatever)?

    1. Buzzword

      Re: Revision codes

      You can look up the list of revision codes in use here:

      https://www.raspberrypi.org/documentation/hardware/raspberrypi/revision-codes/README.md

      Presumably when a new model comes out, they'll update the list.

      1. Anonymous Tribble

        Re: Revision codes

        There are already reports of a Pi 4B rev 1.2 in the wild. No idea what changes it involved.

        1. werdsmith Silver badge

          Re: Revision codes

          Firmware has already improved the thermal problems a lot.

  10. Breen Whitman

    Its a shame. RaspberryPi is the leader and the standard so a shame when the ball is dropped like this because it makes the Chinese competitor boards look better. They usually trounce an RPi in so it is damaging when their is errata like this

    1. blcollier

      They'll still remain the market leader, despite hardware niggles. Other SBCs might be more powerful or have more features, but very few support their products like the Raspberry Pi Foundation do.

      FWIW people were saying that it would never succeed because of hardware "issues" right back at day 1, nearly 8 years ago. The original launch model was *very* touchy about USB power supplies and prone to brownouts on the USB bus. IIRC, the hardware was designed with the actual USB voltage spec in mind - 4.75v to 5.25v - but many USB phone chargers simply couldn't deliver that and their voltage dropped below 4.75v when under load. Cables were an issue back then also: even if a PSU could deliver in-spec voltages when under load, poor quality MicroUSB cables often caused a voltage drop meaning that the voltage at the power connector on the board was now out of spec. There was also a hardware design flaw that caused the USB/LAN controller to draw way more power than it should do. Yet here they are nearly 8 years later with over 25 million units sold.

      1. Paul Shirley

        A little more experience of the real world of cheap 'good enough' hardware and they might have realised if lithium cells are charged to 4.2V max, charger designers are likely to ignore the USB spec.

    2. werdsmith Silver badge

      The competitors trounce the Raspberry Pi on the specification list.

      Then somebody buys the competitor and tries to use it. Then they buy a Raspberry Pi.

  11. YARR

    Firmware?

    Could it be caused by the recent firmware updates to increase CPU performance before thermal throttling kicks in? To allow the CPU to run hotter + faster, other support devices must have been configured to use less power, resulting in unpredictable behaviour?

    1. bish

      Re: Firmware?

      Seems like a decent theory. I definitely don't buy into the suggestion it's purely hardware - I don't remember any complaints about WiFi connectivity at launch.

      1. werdsmith Silver badge

        Re: Firmware?

        Raspberry Pi have a fantastic history of holding their hands up and giving full disclosure of any problems. It's not their way to give mealy mouthed excuses and fudged defensive statements like we are used to from the big tech companies. So based on previous I would believe that we know what they know.

  12. Anonymous Coward
    Anonymous Coward

    I didn't bother buying a pi4 to complete the set

    this since it was obvious, to me, at launch that design and build compromises I did not agree with had been taken.

    1. James Hughes 1

      Re: I didn't bother buying a pi4 to complete the set

      On the other hand, obviously agreed with by the millions who have bought them. The phrase cut off nose to spite face comes to mind. Although would be interesting to know what compromises.

      1. Anonymous Coward
        Anonymous Coward

        Re: I didn't bother buying a pi4 to complete the set

        What I see is an opinion based on personal preference getting -ve votes

        When you get that level of fanaticism then you can expect to see lots of unsuspecting people getting hurt because of fanbois blind faith and personal investment.

        Once you are proven wrong are you going to compensate all those people who were hurt by being taken in by your faith? Not that fanatics ever accept proof but it would be nice for you suckers to accept some responsibility for once

        <no godwins from me> but I still recognise the symptoms

        As to "cut off nose" in my opinion it is more of a tail than a nose i.e. once useful feature being omitted as it comes with major drawbacks in the new niche

        1. James Hughes 1

          Re: I didn't bother buying a pi4 to complete the set

          Not entirely sure what you are trying to say.

  13. SuperGeek

    Not just the Pi 4

    My original Surface Pro will not let me have WiFi and Bluetooth on at the same time, WiFi goes unusable and drops.

    They are both controlled by the same chip...

  14. bish

    Bah

    Since launch day, I'd been using mine as a headless development server, but recently replaced it with a full blown PC so have been trying to repurpose it. Have been tearing my hair out over weird WiFi issues for days now (at 1080p, it won't connect to a 5G SSID - 2.4GHz is fine, but seems to dropout periodically). It's undoubtedly an incredible feat of engineering to squeeze so much capability onto such a small board, but it is beginning to feel like all that squishing came at a cost. That said, my suspicion is that this is actually a software problem: I'm getting some weird errors in logs, and find it extremely odd that these issues weren't raised at launch when everyone was wanging on about CPU temps. So I suspect the 'hardware interference' theory is a red herring.

    1. James Hughes 1

      Re: Bah

      That sounds entirely unrelated to the issue at hand, which we have got a fairly good grasp on now. I use Pi4 at 1080p, connected to 5Ghz with no problems at all. Something else is amiss. Try asking on the forums.

  15. Leedos
    Megaphone

    RF can be strange

    Not just the Pi. USB3 and Logitech Unified receivers. I've had other issues with a Gen3 AppleTVs and HDMI flicker / HDCP errors. I moved and all is fine, same TV and cables. I have faith in the the nex rev. 'RPiV'?

  16. Anonymous Coward
    Anonymous Coward

    So ... WiFi fails for random developer and two other people and El Reg posts story seemingly without validating claims. I have three Pi4 for development work and they all work fine at high resolutions without adverse effect on WiFi. Maybe I’m lucky but the Pi forums are pretty quiet on this.

  17. Pascal Monett Silver badge

    An RPi as a desktop computer ?

    I'm sure that the latest generation can be used as a desktop computer, but I am also quite sure that it is not a desktop computer.

    At least, not compared to mine.

    And, when I check the specifications, I can see the difference.

    The CPU is a quad core 1.5GHz thing. Respectable, but an i7 6700 trounces that without breaking a sweat.

    The RAM can go to 4GB, and it is DDR4 - congrats. I have 32GB.

    The Pi has Gigabit Ethernet, just like mine.

    As for video, I have a MSI GeForce GTX 980 TI LIGHTNING with 6GB of DDR5 RAM. I doubt the Pi holds a candle to that.

    That said, the Pi 4 has one great advantage over my rig : it can apparently operate on a 2.5A power supply.

    That's not enough to turn on my CPU.

    So, the Pi is undoubtedly a respectable little thing, and if Apollo 13 had that, they would have had less energy problems and largely enough computation power.

    But it is definitely not a desktop.

    1. Chemist

      Re: An RPi as a desktop computer ?

      "But it is definitely not a desktop."

      I too have a i7 and it has a much higher performance as might be imagined (for a laptop costing £650 5 or 6 years ago). But the Pi 4 is definitely usable as a desktop for modest tasks. As I mentioned earlier it will even video edit (using kdenlive), rendering the video takes about 4 times as long as on the i7. Playing 1080p50 video is very efficient with the built-in command-line player using the GPU (~~1% processor). and OK with vlc (~16%) from memory. I've run some processor intensive programs from my molecular modeling days and the drop-off is again ~ 4 fold from this machine. I have a multi-threaded script that converts a directory of RAW photos (~5K*4K pixels) into 1080, sharpened, jpgs for thumbnail purposes and it does that again about 4 fold slower - so I've given it some stick

      Have you actually used one or are you going on specs. ? Mine hangs on the wall behind the monitor BTW. The other advantage you failed to mention is the price.

    2. Paul Shirley

      Re: An RPi as a desktop computer ?

      Desktop/gaming/workstation are (fairly nebulous) workload descriptions, not silicon dick size comparisons. Compared to the crippled laptops most people do 'desktop' tasks on, a Pi holds up well.

    3. ChrisC

      Re: An RPi as a desktop computer ?

      Next you'll be telling us that a Ford Focus is definitely not a car, because comparing it to a Bugatti Veyron it loses out in pretty much every category except "number of wheels"... And in the game of PC Top Trumps, your system sounds like a bit of a wimp compared to some - only 6GB of VRAM, pffft, only 4 physical CPU cores, oh you poor thing, however do you manage?

    4. John H Woods

      Re: An RPi as a desktop computer ?

      Most laptops couldn't hold a candle to that spec either!.

    5. werdsmith Silver badge

      It definitely is a desktop

      I have one right here working as a desktop computer.

      Any list of specs and performance are totally irrelevant. Otherwise your house is not a house a car unless it's a grand mansion.

    6. Carpet Deal 'em Bronze badge
      Facepalm

      Re: An RPi as a desktop computer ?

      Most people aren't going to use a computer for anything more demanding than opening a web browser or playing a video, for which 4GB of RAM and a dinky GPU is plenty. You also can't just compare clock speeds like that, since the Pi uses an ARM core instead of an x86 chip.

    7. James Hughes 1

      Re: An RPi as a desktop computer ?

      Specious argument. In three years time, when desktop PC specs are so much better than your desktop is now, does it suddenly stop becoming a desktop? Of course not.

      I've just taken a few old tower system down to the tip. They were desktop PC's. None of them as fast as the Pi4.

    8. John Brown (no body) Silver badge

      Re: An RPi as a desktop computer ?

      "But it is definitely not a desktop."

      Define "a desktop". You told us what your personal desktop is, but that's not a desktop by my definition since mine is a different spec to yours. So you are wrong and I am right. Or vice versa.

      For many "average" home users and possibly many average office users, a RPi4 is easily enough power for their daily needs. (Other than most users want/need Windows 10, of course)

  18. password1234567890

    first world problems right there.

  19. razorfishsl

    Harmonics........

  20. techmind

    30 years ago, when we had analogue radios...

    The people of the day soon learned that radios operated in the proximity of various computers and other electrical devices would cause interference, which would manifest as various buzzes, whistles, whines and other audible noise. You soon learned what sort of sound of interference was caused by what sort of appliance.

    Despite the claims of the proponents of digital comms, these interference issues haven't gone away - they've just been hidden. Your digital wireless device works... until it randomly drops out - and you're left with no clue as to what the source of the problem is.

    A £150-£200 software defined radio (such as the SDRplay RSP2) in the right hands can be very useful for identifying interference sources below 2GHz.

    (The £20 RTL dongles while they demonstrate the principles of SDR have so much self-interference and poor image rejection that they are not very useful.)

  21. eta-beta

    It appears that the issue is due to RF interference from the HDMI ports. Those HDMI ports can generate some nasty harmonics at high bitrates that can swamp out the WiFi signal, this is confirmed also by the fact that the issue is less severe the 5GHz band where these harmonics are at lower levels. The only fix would probably be a proper board component layout, hoping also that they adopt a full-sized HDMI port in the future.

    1. James Hughes 1

      No, that's not the only fix.

      And I doubt we will move back to full size HDMI.

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