LINUX KERNEL variants explained: Zen, Xanmod, TKG, RealTime, Liquorix...
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- čas přidán 3. 06. 2024
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Timecodes:
00:00 Intro
00:35 Sponsor: TuxCare
01:49 Linux Kernel
03:08 Generic Stable kernel
04:54 LTS Kernel
06:03 Libre Kernel
07:05 Hardened Kernel
08:09 Real Time / Low latency
09:48 Android kernel
11:05 Zen, Liquorix and Xanmod
13:00 TKG kernel
13:47 What should you use?
15:15 Sponsor: Tuxedo Computers
16:26 Support the channel
The "official" Linux kernel, straight from Linus Torvalds and all the kernel developers, you generally see a new version every 2 to 2 and a half months.
All stable versions of the Linux kernel are numbered in the usual scheme, so major number DOT minor number, but they also have really strange codenames. Some distros tend to modify these kernels with additional patches, or features that haven't been added yet, which is why you can see some kernel versions with a "-ubuntu" at the end for example.
Certain kernel versions are also marked as LTS, meaning Long Term support. These are versions that will be supported for much longer, up to 6 years. The Linux kernel project recently reduced that support window to 2 years.
Since both the stable and LTS kernels ship with some non free firmware, there's the Kernel Libre project, which removes all of that, to only ship software and code that is completely free, as in freedom..
Next, we have the hardened kernel. It's not an "official" project per se, it's a kernel version that certain distros ship in their repos, like Arch Linux for example. It's the stable kernel, with an additional patch set applied to it to make it more resilient security-wise.
Next, we have the realtime kernel. The goal is to reduce the latency between a task being assigned to the CPU, and its execution, and it's mainly meant for industrial applications, or for audio production.
This, in turn, makes it less efficient for multi tasking, and it requires a lot more manual config to be efficient, and applications need to be specifically tailored to take advantage of this lower latency.
The low latency kernel variants do the same thing, but at a lesser degree: it still lets you pre-empt CPU threads like the real time kernel, but it isn't as regular as the realtime kernel.
The Android kernel is focused on supporting a specific category of devices, meaning that it has optimizations for these exact things.
The Zen kernel applies a few fixes and improvements meant to have the best performance and experience for linux desktop users. It's also packaged as the Liquorix kernel for Ubuntu or Debian, and other distros, although Liquorix isn't exactly like the Zen kernel.
Another version is the XanMod kernel, with sort of the same optimization as the Zen kernel, and a few more on top of that, with the same goal: improving the performance of Linux systems.
Finally, we have the TKG kernels, and I'm saying kernels, because TKG isn't a specific Linux kernel you can download and use, it's more like a build system that lets you choose a few specific patches and compile your own kernel with that. - Věda a technologie
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That should let them get some of us that feel like they would otherwise be wasting the time of a representative just for a single server or small home lab.
17mins of usless info, who needs a kernel with a recent backdoor?
I already googled this ages ago but I guess having a Frenchman explaining it would be much better
I just skip the googling at this point and it's only partly because I have a crush on him lol
It is indeed better. I just look for this guy's videos for my Linux questions nowadays.
Hey! 🧐 Get of your high horse. We all deserve to know them. Not just those that can Google it. 😉 If that means a food public video about them, then that's great.
Google searches are just awful and bot content now. At least We'll make sure to get info from a person.
Back in the day, I used to compile every kernel that was released, optimizing it for my system...that is, removing device drivers for things I don't have, fiddle with which driver is built in or as a module...Every time a new kernel would come out, I would untar it, then read any notes, and then type "make menuconfig", and later "make xconfig". These days, the kernels that get shipped with distros are generally pretty good. My systems today have a lot more horsepower and thus don't need as much, if any optimization for what I do. But I do remember the overnight kernel builds...and the excitement of seeing if it completed and installing that kernel to see how it works. Sort of like Christmas after every kernel release!
Imagine if your channel was called The GNU/Linux Experiment. Jeez, that sounds even more nerdy that it already is!
Haha yeah, no way, people are already confused with just « Linux » 😂
I'd like to interject for a moment. What you're referring to as GNU/Linux, is in fact, GNU/systemd/Linux, or as I've recently taken to call it, GNU + Lennart Poettering + Linux.
GnyUwU/WinUwUx Kewnew
@@TheLinuxEXP Do it! Change the channel name to 'The GNU/Linux Experiment" for a week and see what happens
@@felixfourcolor systemd/linux go harder tho
Shoutout to TheGloriousEggroll. Dude maintains his kernel version and a Fedora spinoff, both geared towards one goal: the performance of Wine applications. So, if your Windows past does not let you go completely, it may be a useful option for you.
Zen, Xanmod, and a few others tend to include these wine kernel modifications before mainline does too. Thats the main reason I got over to xanmod was that it had a few extra out of mainline modules and other fixes upstreamed into them for Wine/Android/network stuff. Just seamed easier then compiling it myself.
Well, Nobara is kinda outdated at this point...
@@p0xygenwhat do you mean?
@@p0xygen Then Arch is retroware.
@@burningwp He used to actively update it, but stopped in December.
You mention that linux hardened is more often used on cybersecurity experts which is half true. Usually you want that kind of stuff on internet-related servers (DB server, Web servers, etc.) that don't rely on special hardware but are prone to be attacked since they have direct access from internet.
Those servers aren't dependent of systemd?
11:26 Fun fact: In Turkey Smartboards at schools uses Pardus Etap(Debian based OS) with Liquorix kernel installed.
One argument for the Zen kernel that recently became true, if you own an AMD GPU, and the vendor has set a crappy power limit due to "Must win benchmarks hurr durr!".
You can actually override it and set it lower to make it run cooler for an example, while the normal kernel will refuse to disobey the crazy vendor limits.
Another argument for it is that in my experience it does not introduce new issues compared to the mainline release.
It anything it prevents problems thanks to the desktop optimised defaults, like being early with increasing the maximum nmap count.
the TKG kernel has an amazing system of incremental configs, every time you modify the kernel config you will be prompted to save the changes as a new "fragment" which you can then load before next configuration (or you can choose to skip specific ones) and it lets you do rollbacks very easily if it breaks something without starting from a blank config or spending hours trying to remember what changed recently
The Zen kernel and other "tuned" kernels are dangerous and should not be used by the novice user which we are seeing far too often today. I can't count how many times I have had to tell people to switch back to a standard kernel after reporting faults in the projects I support because the faults were directly caused by the kernel they were running. Do NOT use the Zen kernel if you are using KVM/Virtualization (aka, libvirt) and want good performance and low latency in the VM! The tweaks made to the kernel impact the guest VM performance considerably because it's no longer configured correctly for these workloads!.
what is insane to me is that so many contributors focus on such specific optimizations, yet completely miss a fundamental issue in the kernel/schedulers: high disk I/O freezing the system. it's been an issue forever, and it makes the system unusable. even copying a multi-gigabyte binary file can cause a system to freeze. it's pretty insane how if you look this up online with the hopes of finding fixes, you only find other people being perplexed at this still being an issue in 2024...
Linux distros and desktop environments don't set proper per-process ionice values or VM (virtual memory) and writeback tendencies (swappiness) by default. I'll be honest, I wish they did. The kernel can't fix anything without knowing what processes are critical to system responsiveness. Play around with those until your DE of choice can hold itself together under stress. Grab your DE's compositor, the X server (if you still use X), the DE shell, and write a script that runs on startup to give them realtime ionice values.
All kernels already have every piece of the puzzle necessary to avoid I/O process starvation by using parallel scheduling queues for different processes. But ultimately, no kernel can predict on their own the nature or optimal priority or scheduling mode of I/O operations, regardless of operating system. Windows and MacOS cheat by giving their own OS processes max priority at the cost of third-party software performance, which is why when Windows installs updates, all hell breaks loose and third-party apps running in the foreground stop responding anyway. MacOS is a little smarter by letting apps call into its media processing/GUI/rendering APIs that it then gives max priority. But Linux makes no assumptions, all processes are equal, and by default favors maximum throughput at the cost of latency, letting long-running I/O tasks starve smaller ones. This is a generic approach that works perfectly on servers, but is terrible for desktops. For optimal desktop performance, Linux needs hints from userspace. That is, from you or the developers writing the apps you use.
@@3lH4ck3rC0mf0r7 I appreciate your answer as it’s very well written, but you cannot expect the user to do all this (especially if talking about mass adoption). you and I are interested in these kinds of things, but when people talk about mass adoption of linux as an OS, this is why people don’t use it. if they can’t have a simple reliable system to use and a simple thing like copying a file freezes the system, they’re not looking for an explanation and ways to debug, they want it “fixed”.
I myself have played with most distros and DEs over years and they all have the same issue. even server distros running headless have the same issue. the consensus seems to be “just wait for it to finish”, which is insane. i would 100% of time much rather have a system which is reliable and doesn’t freeze at the cost of a 10% hit in performance. windows does it really well by prioritizing OS processes like you said, I genuinely believe this is how it should be; what is throughout good for if you system halts all the time
Linux releases are actually on a schedule, it's first a 2 week merge window, then 7 release candidates every sunday (sometimes 8 or even 9) then a week later it goes stable. So that's 10-11 weeks between major releases, or 12 in very rare occasions.
So from 6.4 to 6.5 there are 10-12 weeks?
I was just asking myself: What are the different types of Linux kernels
And then your video got posted.
Taking about perfect timing
Haha always nice when that happens!
I've been hearing about some linux kernel variants recently. But at least I'll finally know what they are.
Edit: Apart from stable, lts, and hardened.
Linux is spying on you.
No, srsly, if it was a Windows or Android channel, someone would have already said that it is spying on you.
The reason for using Liquorix for me is GPU passthrough to qemu vm's. Not sure today, but a few years back it was the only kernel to support the features necessary to do this, such as iommu group management.
I've been doing gpu passthrough with qemu/kvm for years using the default kernel, of course you are stuck to the iommu groups that came from your motherboard vendor, this is why the best thing to do is to buy hardware with good iommu groups and even better with ACS support
Kernel Self Protection Project is like hardened but tries to upstream
Nice! I had not heard about this one, sounds interesting!
I find it amazing how one of the best most popular releases of the Linux kernel had “Don’t use” as its name in the first release candidate.
To those thinking about messing with their kernel: make backups first. Like, full disk backups.
Where do you store such a backup?
@@user-xf5ty9yk7z external drive. If you want to make a full disk backup, I'd recommend using Rescuezilla. You can also just use tools like Timeshift to make backups you can restore from
@@user-xf5ty9yk7z External hard drive? I usually just rsync my home folder on it
I run Xanmod with the preempt RT patches applied on top of it (built with Clang and LTO enabled). At least the Xanmod patches are necessary for getting anything remotely decent out of Debian for real-time audio, but adding preempt RT helps too. This setup got me from a buffer size of 512 (48kHz) down to a buffer of only 64. I also found out the smallest buffer PipeWire supports is 48.
So yeah, these patches are definitely good for reducing latency. I haven't noticed any slowdowns in other areas, though I didn't do any before/after benchmarks outside of real-time audio.
inb4: Not all the kernels. Even if the video wouldn't be too long, I have doubts that all the kernels can even be found, let alone knowing wtf differentiates most of them 😆
Oh yeah, for sure 😂
Merci beaucoup monsieur. For explaining the differences. 👍
The main advantage of the Zen kernel isn't increased performance, but how the system handles resource hungry processes. My desktop freezes if it's running the stock kernel and something decides to use all the CPU time, but Zen makes sure that other processes get some CPU time and the system stays responsive enough to find and fix the problem. The stock kernel is tuned for servers. On a server a process that's eating all the resources is probably something important that should stay up even if it means less important things have to wait. On a desktop you probably don't want the kernel to decide your DE is an unimportant process just to save 100 milliseconds on a video encode.
what's with these bots on CZcams recently?
It’s incredibly annoying. I keep blocking them, but they’re better at creating more than I am at banning them…
Nothing. They're as prevalent as ever, it just so happens they are more common on this channel right now
@aqua-bery it's not only this channel. I've noticed the same type of bot on other channels shortly after upload aswell
@@davidddo thats been happening for years
@dianaisnthere well in general, bots have been around since the internet started but i mean the ones that are rampant as of lately
15:05 I'd extend this to: The generic stable kernel works fine for 100% of use cases, and has no notable downsides compared to the others in 99% of those use cases
I started using Linux on Dec 4th 2023 so it has now been just over 6 months. I started with Mint on my primary drive for the stability and ease of switching to Linux and then used a second drive to play around with stuff. Installed Nobara, Garuda, Ubuntu, Kubuntu, KDE Neon, Arch and a few others on both my laptop and the second drive and tested different kernel versions with all of them before finally deciding on Arch with the zen kernel for my desktop and KDE Neon with stock kernel for my laptop.
Like a lot of other topics, when describing or discussing a complex topic, it's probably not true all the time but still useful to know most of the time.
Probably most importantly it can be important to know if the features you need are in the default kernel you're using and if you need features that aren't recompiled, you will to select a different kernel or go through the process of adding those features yourself which can sometimes be easy or difficult depending on whether the features are Ring 0 core features or not.
Often less critical features can be added on the fly during bootup or even after the system is up and fully running. The kernel can also be re-optimized at any time even in demand. Subsystems and configurations can even be swapped out as desired.
Especially if you wish, it can pay to reallocate resources depending on personal use so for instance since I connect only wirelessly, I've minimized completely any resources dedicated to wired connections and implemented optimizations appropriate for wireless connections. The opposite should be done for servers regularly.
I use zen. It's so nice. Really fast.
I should try it as well and compare performance!
Do you know what the differences between zen and generic are? Like which is more performant, stable, which one has better support and so on?
@@aqua-bery I don't notice any stability issues with any kernel except sometimes when the GPU driver locks up in very consistent ways, e.g. when trying to launch Helldivers 2 without the DirectX 11 option turned on. This bug hits both.
It's difficult to quantify how Zen is better, but upon installing it I can immediately feel it. It's less stuttery and the desktop feels smoother, possibly with lower latency. Games stutter a lot less.
It also uses less RAM. For example, my computer can run the Mistral 13b AI model on it, but it cannot run it on the regular kernel; I run out of RAM.
I think if you were to benchmark the frametimes you would probably see it.
@@aqua-bery My experience with zen is that its better at scheduling the CPU for interactive uses. Theres only 1 CPU scheduler in the kernel, and the default one is tuned to server use cases, not laptop/desktop ones. This can result in things like stutter, audio crackle, etc when at high load with the default kernel. I find these problems go away with zen because they patch in a different CPU scheduler built for desktop/interactive use. I don't know or care if there are actual performance gains as thats not why I use it, I use it for the removal of papercuts around resource scheduling in a desktop use environment. Many of these papercuts going away can make it feel more performant even when its not, just because stutters and hitches around your interactive use go away.
No. Look at 11:55. It's like Linus Torvalds said: Tuned kernels are not needed anymore.
I've been trying to understand what was the difference between all the different kernels for a while now, but googling didn't really give me the digestible information I was looking for. Thanks for the video! It really came at a good time.
Excellent, thanks. I was wondering about this just a couple of days ago.
Nick, as always, thanks alot for these useful information
Enabling Liquorix over the stock kernel on MX Linux showed amazing noticeable performance gains on my old i3-3220.
I use cachy, v3 / v4 optimizations where i don't have to compile it myself is convenient.
Same here.
Been waiting for this video, thanks :).
exactly the video I wanted to see!
I was already intending to research into what variant I might want to try and use :3
In my opinion the LTS kernel is the best out of them all, it just works with no problems and it's stable as hell
And using a different one then the stock one could hurt performance on other things... For instance you get use the gaming kernels, but some productivity software will be slower. The stock one is where everything runs good without hurting something else, so balanced.
Very informative, thank you!
ive noticed a massive improvement, especially for audio production, with the liqourix kernel over the mainline. even installed it on fedora lol!
I heard about a Development branch of the Linux kernel for once developer which has so many experimentational features
Wish I could give more than one upvote ... clear and well done, thx!
Extremely informative! Demystified a lot of the Guru Wizardry at the foundation of Linux and opened some avenues of exploration for optimizing my media production systems.
Thanks for a brilliant overview of some of most used kernels.I have found that my RichARCH installed Arch system works great with the Zen kernel for GPU passthrough. The Zen just worked better for grouping PCI devices and made setting up of GPU passthrough a lot simpler.
I always just run the latest stable and have never had a problem
Thanks for the great explanation. I appreciate the work you put into subjects like this.
My pleasure!
Sweet YT! Thank you!
I've been thinking of using the libre kernel
I think it’s worth a try! If some critical component doesn’t work, you can always go back to the generic one :)
Good video!
Hey Nick! I'm loving my Tuxedo Laptop! Thanks for recommending it! (Polaris 17 AMD)
Glad you like it!
Thanks for the good content! Want to try all the filesystems next?
For kernels that aim to improve desktop responsiveness it might be hard to really put it into numbers with a benchmark, but it can really be felt when you use the desktop. Especially with multitasking.
Of course, it may or may not feel like a big difference depending on your software, hardware and how sensitive your are to lag and stuttering and such things (because this definitely varies between people).
Geeks are the only people in the world who enjoying calling themseleves "low level" and that's where they remain literally and metaphorically. Isn' t in funny ,that they callout on a few good youtubers who have made *Linux* famous and common place. Who cares its called "Linux" or GNU/LINUX. What matters is, that its free, its fun, it doesn't track you, doesn't shows ads and has a great community !
All hail Algo, the rithm king!
Hello old friend. I missed this .
I use the Zabbly variants. On 22.04
The real time one is kind of funny because it's still so big that is impractical to audit for use cases that really need that.
Industrial automation need real time on the edge of processing, but the management computer is not always required to do that (but is a good feature to have).
I have to say I did chuckle at the kernel name for version 3.11 (and tbh even if you didn't know it you could probably take a guess and be right).
2:43 Technically, that would be the boot loader (not counting firmware), but the kernel is the first part *of the operating system* that starts. The bootloader comes before, but also gets out if the way before anything else happens. The kernel stays and is the core of all normal operation.
To be precise, the zen kernel doesnt ship a different scheduler, it changes the configuration of the same CFS scheduler used in the kernel until very recently. IMO the recent switch from CFS to EEVDF for the upstream linux kernel is more significant.
Outstanding video
Nice video.
I use tkg. Did a localmodconfig and tweaked it myself for example i never use sata so i excluded it and i ended up with a config file so mimimal that it compiles in less than 5 minutes on my 8 thread i5. I can always have the lastest kernel version and i feel like i have the control of my system. Its really good
Nick I want you to make a vid on cachyos
it literally delivers value :)
I'm using the amd raven kernel
Regardless what kernel you use, I would always recommend installing an LTS kernel alongside it as backup. Especially on bleeding edge / rolling release distros. If you have some hw driver/compatibility issues or the update process breaks (bad initramfs image for example) you can boot the LTS kernel and fix the problem without chrooting. Makes troubleshooting allot easier and it doesn't require much space.
j'adore tes vidéos je les comprends sans mettre de sous-titres ça fait apprendre l'anglais
Yes
the DistroTube callout at 2:16 is hillarious
@14:12 Don't forget to mention the gui istaller called mainline kernels.
@15:15 Unless you want to improve your gaming performance with the latest features.
Use the tkg-pds kernel mainly because it makes big little cores better for gaming
Will be interesting to hear what you say, since those kernels are pointless now. They had a point 5 years ago when they included patches that weren't upstreamed yet. But now the vanilla kernel has great tuning and support. Edit: 11:55 covers it perfectly. "Tuned" kernels are not really useful anymore.
11:00 remebered some lenovo laptop advertisement 5 years ago or so that was released with either Windows or Android (specifically android, not Linux distro in general).
I would add to this debian kernel. I am not sure if you can install it on anything other than debian but it is essentially linux libre but without blocking you to add "non free" parts if you want (if I'm not mistaken).
and of course if you install debian "non-free" version (which recently become more seamless) then you probably get standard linux kernel
The Zen kernel's focus is a responsive interactive experience, not necessarily the highest benchmark scores, so the Phoronix scores are mostly meaningless as a benchmark of how good the Zen kernel is at achieving its purpose, unless they mostly measure latency.
I don't know if it's noticable. I used to use the -ck kernel (~a decade ago), which was a similar patchset, now part of Zen, but didn't notice any differences. I was also not looking closely for them.
I wouldn't use zen if I didn't have to, but for VMs I need the ACS patches, and zen has them pre-merged.
I'm on Arch, and use the newest regular Kernel, the LTS as a fallback, and the Zen for when I am recording music, as it has a more suitable IRQ priority management method, which is key to lower latency; Nothing like getting X-runs in your recording after you just played some part better than ever (Did I just play that???🤯), and know you may not be able to repeat it any time soon, nor can you use it!🤬🤬🤬
i use linux zen because between liquorix & xanmod it is in the arch repo & get a update when the mainline kernel also gets it the other 2 are slower
I use zen kernel as it package binder with it
i remember that arround 2011~2013 i wantd to do some media production involving jack rack, but my audio laged a lot.
people told me to use an real time kernel, but the process was way too complicated for me.
i hope pipewire solves that and i dont need an real time kernel anymore.
or maybe purchasing an new cpu...
for a moment i tought you would speak about why different distros use different versions of the kernel, that is, to have control over a certain version and be able to do whatever with it, without the need to step on the toes of other distros, because why wouldnt they use the same version right :D
I prefer to stick to the mainline kernels, whatever comes with my distro, and I stick to distros that are pretty mainstream and not one-man shops. The Linux kernel is already great. As long as there are security updates being provided by upstream or downstream, you should be happy with it and not worry too much about finding something better.
Zen also has a few compatibility patches applied to it, like the OpenRGB patch to allow communications with mobo and RAM RGB lighting and Anbox patch for the Android emulator, although the latter is not very important now since Waydroid replaced Anbox
I tried Manjaro briefly and never found a use for changing the kernel version. That level of tinkering leads more often than not to a broken system. It's not worth it man.
Mmmm. Tasty fragmentation.
I think you missed microkernel. Still very informative video👍
arco linux offers every types of kernel separately , but to be frank i use only zen and normal one
Whats the best for gaming? Only gaming kernel? Like realtime?
Just a note, Darwin ist not the macOS kernel. Darwin is to macOS what GNU is to most Linux distros. It's a set of core utilities. The macOS kernel is XNU
Is it better to use a custom kernel like Xanmod/Liquorix or using default kernel + gamemode?
whats the purpose to patch a kernel when what piled on top of that i still not secure
Just want to point out: According to Torwalds, the kernel version numbers don't actually mean anything. I.e. 6.0 wasn't hugely different from 5.12. He just thought a .13 would have been too high
What kernel is best to use a MediaTek Bluetooth chip?
I use Xen, btw 😎
No, not Zen.
i guess cachy os kernels worth mentioning
Cachy? Doesn't ring a bell.
Correction: The hwe kernel is NOT the same version as the one the distro shipped
Ubuntu 22.04 ships with 5.15 but if you install the hwe kernel, you get 6.5.
I've tried compiling linux kernel on macmini3,1 since had some crashes with distro kernel. Didn't understand why the distro(debian) kernel was faster than the one compiled by myself: with phoronix tool distro kernel took 10 seconds less on average on gimp task (which take about one minute). Now the macmini is gone and don't have time to further investigate ...
"LINUX KERNEL variants" What? Dude, I NEVER heard THAT before. Wow!
what kernel does the Steam Deck's SteamOS uses?
Regarding what you said about Android on laptops, i would argue Android is a better operating system than ChromeOS and should replace ChromeOS on Chromebooks. I was actually thinking of getting a keyboard case for my Gslaxy tab a9+ so it can replace my chromebook as my low powered portable computer.
i is default lts, and a upstream
Have that text popup everytime you say Linux (and you refer to that and not just the kernel, lol).
Zen
The way I understand this Kernel is, that it does not provide better performance in games or like that, quite the contrary that it is expected to have less performance. Main goal is to have better user experience on the desktop, in example when all cores are used 100%, then the PC will be still usable and react normally without freezing or slowing down. Benchmarks are not the "correct" way of measuring what this Kernel offers.
I recently switched to Zen 2 a few months ago, because I liked its premise and what I read about it. To be honest, I'm not sure if I notice any difference at all. But as said, this is what I understand about this Kernel.