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WiFi 6 gets 1.34 Gbps on the Raspberry Pi CM4
- mciancia 6y agoEh, clickbait title. Suggests speeds of built-in raspberry WiFi which is not the case.
- NRv9tR 6y agoThe implication is more on the reader. I don't expect the title to be as verbose as "WiFi 6 gets 1.34 Gbps on the Raspberry Pi CM4 with pcie wifi adapter." It's wordy enough as is. And anyone who is in the market for this news knows that you aren't getting that with the stock radio.
- zymhan 6y ago> anyone who is in the market for this news knows that you aren't getting that with the stock radio. Well, yes, but the suggestion that it is possible from this clickbaity title is why I'm here to begin with.
- crazyjncsu 6y agoIf we're concerned about wordiness, we could have dropped "Rasberry Pi CM4" from the title as this detail seems irrelevant when the external wifi adapter is doing the heavy lifting.
- geerlingguy 6y agoThat's the main point of this, though—until the CM4, it was not possible to get this kind of card working easily on any kind of Raspberry Pi. There are some other SBCs (usually more expensive) with the capability, but being able to (easily) put AX WiFi into a Pi project enables some new use cases.
- MayeulC 6y agoWhy not? This looks like a much better title to me. Of course, maybe the article wouldn't have been read as much then...
- geerlingguy 6y agoThis also reminds me of the many people who complain about my YouTube thumbnails from time to time. I do have the 'open mouth' from time to time (I hate it but do it)—and the reason is not because I think that's appealing, professional, or amazing. It's because through a lot of A/B testing over the past year, the same quality and subject matter in a given video without a dumb thumbnail gets at least 30% less impressions on YouTube. What use is making great content if your marketing around it can't get people to read/view it? You have to hold your nose to do any marketing (IMO), and there's a reason most of us on HN distrust salespeople and marketing people. But they exist for a purpose. I've had to dip my toes in those murky waters to be able to sustain the open source work I'm doing.
- OJFord 6y ago'Be the change you want to see in the world'? Or just 'decide if you want dumb clicks or reasoned interested'. I hate what you describe about YouTube. To me the worst offender is a chap who used to go by 'Stephen the Robot', but I think he changed the channel name, his actual content is excellent, but I have to sit holding the remote, so that I can skip all his repulsive self-reactions and crash-zooms on his face. It's such a shame, he's working on an awesome project, it's really interesting, (open source scratch built pick and place machine) but the delivery seems to be designed for 'tweenagers' on TikTok. (For context, I'm in my 20s, hardly old and grouchy. I actually might not be older than him even, unsure.)
- geerlingguy 6y agoThe key is to get the dumb clicks (to pay the bills), while not going so far as to disenfranchise the core audience.
- sweden 6y agoAgreed. It took me a while to realize that this was just about compiling Linux drivers for a network card connected through PCIe.
- jeffbee 6y agoJust imagine how much you could get with a wire.
- cbhl 6y agoGetting a wired connection above 1 Gbps seems non-trivial -- there are products that do 2.5 Gbps, and other products that do 10 Gbps. It seems like you'd have to pick one or the other and hope the rest of the world standardizes on the same speed as you.
- zymhan 6y ago10GbE is a standard. It's expensive for home users, but it's very much the standard for faster-than-gigabit ethernet. https://en.wikipedia.org/wiki/10_Gigabit_Ethernet https://en.wikipedia.org/wiki/10_Gigabit_Ethernet
- amarshall 6y ago> there are products that do 2.5 Gbps, and other products that do 10 Gbps And 5, 25, 40, 50, 100, 200, 400 Gbps. > seems like you'd have to pick one or the other and hope the rest of the world standardizes on the same speed as you Huh? A connection between A & B will just be as fast as the slowest link between them, be it 400 Gbps or 6 Mbps, regardless of the various other speeds. And a 10GBASE-T NIC will happily autonegotiate with a 10BASE-T NIC and everything in-between.
- jeffbee 6y agoNot that I imagine it causes problems in practice, but as a point of order I think 10G copper PHYs cannot negotiate below 100BASE-TX.
- amarshall 6y agoMaybe, not sure. I can’t immediately find anything that would specify as such, but I suppose adapters could opt to not support some modes (and I guess technically I may have been overreaching a bit on that bit anyway since autonegotiation is only mandatory at all in 1000BASE-T and later).
- mschuster91 6y agoThe CM4 and the Pi4 hack expose one PCIe lane, correct? Is it possible to use some sort of... port multiplier / switch / hub to run more than one PCIe device on a Pi?
- geerlingguy 6y agoYes; I'm testing two switches currently—see https://pipci.jeffgeerling.com/#pcie-switches-and-adapters https://pipci.jeffgeerling.com/#pcie-switches-and-adapters
- jagger27 6y agoThe RPI4 has a 1x lane of PCIe 2.0. Maybe you could split it into two 1x PCIe 1.0?
- labawi 6y agoYou can split it to two 1x PCIe 2.0, or perhaps even 2x, 4x, probably even 3.0, 4.0, with the right chip, but in any case you need a PCIe switch, and they will share the uplink bandwidth.
- hausen 6y agoThere's at least one reported case of a PCIe multiplier card working with the Pi4: http://labs.domipheus.com/blog/raspberry-pi-4-pci-express-it-actually-works-usb-sata-gpu/ http://labs.domipheus.com/blog/raspberry-pi-4-pci-express-it...
- hinkley 6y agoI've been farting around with Friendly's devices. Several of them have 2x PCIe, which I'm using/will be using for persistant storage, but I don't think you could compare anything they have to the compute module, especially with respect to PCIe.
- ksec 6y agoRaspberry and Linux Drivers issues aside. This is 1.34Gbps on a 2x2 5Ghz 160Mhz WiFi 6 with theoretical speed of 2.4Gbps. I could get very close to 800Mbps on my WiFi 6 on iPhone. So I was expecting 1.6Gbps with 160Mhz. With Wireless speed over taking wired, we really need 2.5 /5Gbps Ethernet, but the move to these standards are so slow.
- Dirlewanger 6y agoWhat? Cat 6a is 10Gbps so the actual speed is probably more than 5Gbps.
- lostlogin 6y agoI think the parent post is referring to the low rate of adoption of >1gbps networking. Switching and routing is expensive and not many devices support it.
- amarshall 6y agoThey’re presumably referring to 2.5GBASE-T and 5GBASE-T. Some motherboards and WiFi 6 WAPs are now including NICs meeting these standards but not 10GBASE-T. Still not commonplace throughout, though. Both 2.5 & 5GBASE-T are rated for 100 m on CAT 5e. https://en.wikipedia.org/wiki/2.5GBASE-T_and_5GBASE-T https://en.wikipedia.org/wiki/2.5GBASE-T_and_5GBASE-T
- ksec 6y agoYes the point of NBASE-T or 2.5/5BASE-T is that it should be a lot cheaper than 10GBASE-T.
- wongarsu 6y ago10G Ethernet has gotten a lot cheaper, certainly viable for enthusiasts. I'm not sure what I would use it for except for faster access to my NAS, and that's coincidentally also the one device category where 10G ports are somewhat common. For everything else 1G per device seems plenty, and with Ethernet you actually get the advertised speeds in typical scenarios.
- NikolaNovak 6y agoIgnorant questions, if I may: 1. How come today, for home use, WiFi seems to exceed the price/performance of hard-wired? Is the Ethernet standard lagging, or lack of interest/demand, or some more physical barrier? 2. Related, for somebody who wants reliability, is Ethernet/wired still a sane choice, or does that just make them an old geezer? In urban setting with overlapping wifi cards all blasting full strength at their neighbours, is real-life wifi performance actually near as good as wired performance?
- centimeter 6y agoVariance and latency is much higher with wifi than with wired. Sensitivity to interference is also a problem. Dropped packet count is usually much higher with wifi, which can wreak havoc on many applications.
- deleted 6y ago[deleted]
- ProfessorLayton 6y agoPerhaps things have changed since I last upgraded my home network, but iirc, advertised wifi speeds are half duplex, while wired speeds are full duplex — i.e. wifi speeds are for the combined upload/download while wired can go full speed in both directions.
- 411111111111111 6y agoIt's even worse, because wireless is basically a hub. Or phrased differently: there is only one wire available for all devices on a wireless network, and your (as well as others on same frequencies) devices have to figure out which packet is for which device by themselves.
- ConceitedCode 6y ago1. Taking a shot in the dark - Maybe check your ethernet cables? Not all ethernet cables are the same. If it's a cheap / old ethernet cable then it might not be rated for the same kinds of speed as your wifi. There is a chart on this page labeled "Ethernet Cable Performance Summary" with some stats for different ethernet cables. https://www.electronics-notes.com/articles/connectivity/ethernet-ieee-802-3/cables-types-pinout-cat-5-5e-6.php https://www.electronics-notes.com/articles/connectivity/ethe... 2. Yes, although in my experience this is very minor. On my network - good wifi has a 3ms latency and good ethernet has a .3ms latency. While that is a 10x improvement, in the scheme of things I don't notice 3ms of latency. I live in a high rise condo with lots of interference in a major city and can't say it's caused me any issues.
- hinkley 6y agoIs there any flavor of hardware that lets me use PCIe as layer 1 for a TCP/IP stack? Specifically, with a switch in the middle instead of daisy chaining?
- moonbug 6y agopcie switching is a thing, but it's wasted on IP.
- hinkley 6y agoAre you sure? Isn't the point of NVME that it has lower latency than speaking SATA to flash memory? I've seen switches for putting a whole bunch of devices onto the same motherboard, but can you have a whole bunch of motherboards talk to each other directly?
- moonbug 6y agohttp://www.dolphinics.com/products/MXS824.html http://www.dolphinics.com/products/MXS824.html for example. My point was that you don't buy those and then layer TCP/IP on top of it.
- JeanSebTr 6y ago> Have you ever started a project that should take a couple hours with a fifty dollar budget, and realized at the end you spent a whole month on it and spent close to a thousand bucks? Ah man, costs aside, that's my last weekend and probably the next few ones as I've been trying to make my old Motorola Xoom tablet run a modern kernel. When/if that's completed, the return on investment will be a net loss.
- geerlingguy 6y agoBut the experience may net you something... an ounce of pride, or maybe a pound of regret, depending on how it goes!
- JeanSebTr 6y agoDefinitely! Already to have successfully compiled a working kernel is an achievement as most of my last attempts over the years failed. But I really want to satisfy those demanding user-space binaries who complains the kernel is too old. It's quite satisfying to have grown from "struggling to build from source" to hunting 2.36 era patches and diving in the code to port it. A lot of actual learning in the process.
- jacobwilliamroy 6y agoIt'll all be worth it when you post about your hard work on hacker forums and get a deluge of angry comments telling you how you could have gotten thrice the power in half the time for 1/5th the cost.
- jjeaff 6y ago>net loss Well, you could have just sat on the couch watching mindless tv instead.
- voltagex_ 6y agoI'd definitely read a writeup on this. Have you seen postMarketOS?
- 6y ago
- TimSchumann 6y agoHey Jeff -- Just wanted to say I really appreciate you taking the time to write stuff like this up. I know that may be 'the point' of what you're doing, but I also know from personal experience that writing up a comprehensive review/guide/benchmark (whatever you want to call this style of writing) can easily double to quadruple the time investment for a project. Thank you for sharing the troubles and pitfalls for the rest of us to learn from, or even just reference.
- geerlingguy 6y agoI'd say doing the post + video at least 10x's the time involved in one of these projects. A lot of people can get to the 'I did this thing and I got it to work' stage. Getting to 'I did this thing and I can get it to work from scratch a 2nd time' is better. Getting to 'I did this thing and here's my documentation, enough to help you do it too' is my goal, for pretty much anything I work on.
- TimSchumann 6y agoI wasn't even talking about the video, just the write-up. I haven't done much, but video production seems like a black hole of space and time where things are never 'done' and eventually you just release it because it's the only way to stay sane. > Getting to 'I did this thing and here's my documentation, enough to help you do it too' is my goal, for pretty much anything I work on. As they say in the biz, 'You're doing The Lords Work'. Again, thanks, and much appreciated.
- liuliu 6y agoI think the mentioned Mikrotik switch should work with 2.5Gbps port (if you run the router in AP mode)? I've run successfully the mentioned Mikrotik switch against 2.5Gbps NIC and 5Gbps NIC to reach the advertised speed cross computers.
- geerlingguy 6y agoYep; it was a matter of an older transceiver I was using. I am using a different one and it supports 2.5 GbE now. Sadly, I can't edit video on YouTube like I can edit or update a post :)
- skavi 6y agothanks for respecting system theme on your website.
- geerlingguy 6y agoOf course! The day the dark mode feature came out on Safari I added a darkmode theme. I also set background to 000 black, so it consumes less energy on OLED displays.
- CamJN 6y agoAnd yet my RPi4 can't get more than 9.1MB/s over ssh when wired to cat5e, or 17.14MB/s over netcat. I know the connection is good as testing with my laptop I can get gigabit speeds, but the pi insists on being sluggish.
- diarmuidc 6y agoThat's not the networking performance though. RP4 can hit line speed on Gb Ethernet: pi@kodi:~ $ cat /proc/cpuinfo | grep Rasp Model : Raspberry Pi 4 Model B Rev 1.1 pi@kodi:~ $ uname -a Linux kodi 5.4.72-v7l+ #1356 SMP Thu Oct 22 13:57:51 BST 2020 armv7l GNU/Linux pi@kodi:~ $ iperf -c 192.168.0.39 ------------------------------------------------------------ Client connecting to 192.168.0.39, TCP port 5001 TCP window size: 214 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.0.214 port 44960 connected with 192.168.0.39 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.0 sec 1.04 GBytes 891 Mbits/sec
- Tepix 6y agoPut 4 spaces in front of every line. Btw 891 mbps is not line speed
- goalieca 6y agoI just setup my rpi4 as a gigabit router with a USB Ethernet for the wan port. I can hit 980mbps and negligible latency. It’s got slightly more spread on small packet sizes compared to a 300$ gaming wifi router. Where it really sucks is VPN and cryptography since there is no hardware acceleration. It sits mostly idle just doing nat and ipv6 forwarding (and pihole) I’m going to document it once i work out the kinks. Ipv6 was a real learning experience and had to workaround issues with lack of good native ipv6 support in the tooling and configuration.
- tutfbhuf 6y ago> Where it really sucks is VPN and cryptography since there is no hardware acceleration. I know that OpenVPN is super slow on the Pi, but have you tried WireGuard?
- nottorp 6y agoAnd... is there a raspberry pi you can add storage to that has enough bandwidth to write those 1.34 Gbps? I know they have to keep costs down and all, but they could try to put out a version with a m.2 slot. Even sata would be better than these sd cards.
- djeiasbsbo 6y agoI love how detailed the video is, awesome! I recently wanted to cross compile something rather obscure for my armv7 based e-book reader. When I first researched the device I found out that the manufacturer of its chip no longer exists. I ultimately gave up after trying many different things such as compiling different versions of gcc, setting env variables and using the configure script but I just couldn't get it done. Compiling on the device would have been even harder because it only has a statically linked busybox and some proprietary stuff on it. As someone who is younger than the internet, it can be really hard to try something without being able to google it because no one has even tried that yet. But after seeing this video and the fact that you ultimately got this to work, I feel motivated to try this again tomorrow!
- k_sze 6y agoA bit of rant, but the observations in the article just confirm what I have felt about WiFi in the past decade. > When I tested the Compute Module 4's onboard WiFi 802.11ac chip, I got up to around 80 Mbps, even when using an external antenna. > But when I tested the speeds, I was disappointed to find the upgraded card could only pump through 300-400 Mbps on the XPS 13, due to the two-by-two antenna performance and configuration on the Dell. My MacBook Pro, which doesn't have WiFi 6, can get speeds up to 900 Mbps over 802.11ac, so the design of the entire system is extremely important. The landscape of WiFi technology is a complete joke. The consortium and the manufacturers market this crap about 802.11ax being faster, but that's only under ideal, lab conditions. In real-world environments, it's worse than black magic that sometimes works and sometimes doesn't. 5Ghz has such terrible penetration power that it's almost useless. You can barely use a single 5Ghz router to serve a 70m^2 home at acceptable performance. Unlike many houses in North America, homes in Hong Kong are typically built in concrete with rebar, and 5Ghz signals just get absorbed to oblivion within 3 to 5 meters. If you want top WiFi performance in your whole home, you need multiple access points and wire through the wall. But wait, what was the promise of WiFi again? Less wires! The irony!
- angled 6y agoI completely agree! In a not-overly-large flat in Hong Kong, we have three APs to provide complete coverage, and only two of those are connected via Ethernet. The third is a repeater! ~10 other networks are also visible; the density hurts performance as well.
- throwaway189262 6y agoA good "secret" is to use the DFS frequencies most routers won't choose by default. High end consumer routers will allow you to select these frequencies, and usually there's no nearby interference. I have ~70 nearby networks visible but none on my DFS channel. Your signal can drop if the AP detects radar but unless you're near a weather radar station or airport it works fine IMO
- octoberfranklin 6y ago
- nprateem 6y ago> Apologies for the thumbnail—it performs a thousand times better than not-open-mouthed-Jeff in my A/B testing. Really, 1000x better? That's insane if it's true (and explains those irritating thumbnails on YT).
- nextweek2 6y agoA friendly warning, don't upgrade to WiFi 6 just yet, wait for WiFi 6E to future proof yourself. That adds 6Ghz channels, which obviously would contain next to no contention this early in the deployment.