Why is this PCIe Card RADIOACTIVE?

Just to clarify: The clock doesn't use rubidium's (minuscule and totally safe) radioactivity. It uses hyperfine transitions of the Rb atoms to stabilize an oscillator(clock).

Fun fact: the Atomic Clocks in GPS satellites are set to run very slightly faster(?) than the clocks on Earth. Because of Relativity (Gravity and Velocity) causing time to drift apart. If they didn't do that, GPS would lose several kilometers of accuracy every week!

It's working on a Raspberry Pi! Hope to have a video about it soon. No problems cooling the itty bitty NIC on the Pi Compute Module 4 ;)

I would like to see this implemented at LTT - even if the use cases are marginal at best, I think getting tech like this more exposure is super awesome.

People underestimate the power of accurately clocked hardware. It’s amazing how cheaply stuff was put together back in the day… take any two original SNES consoles. They won’t even run at the same speed.

this made me very happy as a developer, like the techs cool but knowing that teams of the smartest people on the planets best solution was "just add 20ms" made me feel great

Slight correction: the rubidium clock has to be synced to GPS not because of drift, but due to special relativity.
At the nanosecond resolution, traveling in an airliner at high altitude could theoretically cause the accuracy to drift.

Ahmad is a generous genius and I support his efforts. Bonus that Linus and co. think his stuff is cool too ;)

"we just whacked 20ms on everything"
OKAY this is a good reminder that whole world is DIY and yolo in solutions that just work

This is one of the coolest things I've seen in my entire life, this has me genuinely stoked for the future, just to see whatever practical implementations people come up with for this tech.

I was expecting an Isotope driven random number generator, for when you want things to be the opposite of precise

I feel like they must have had a bad ntp configuration for that baseline example... I've used it (well, chrony) to synchronize computers for robotics work, and the time difference between them has never been close to that large.
I believe you can also designate one local machine to serve as a time server for the rest of the network, then you should be able to synchronize to roughly within local lan latency.
Obviously the atomic clock hardware will give much better results, I'm just saying that you can get much better than shown without it.

I love this type of content. Sometimes you really need to see what tech is beyond video production and gaming or seeing Linus tear his house apart.

I've gotta say... Linus is a seriously legit "computer geek". He knows his stuff. I remember hearing about this card a couple weeks ago, but I had no idea that it had such wide-ranging utility.

I'm currently working towards becoming a software engineer in my spare time, and stuff like this genuinely gets me to audibly exclaim 'fuck this is cool'. It makes me want to work harder and inspires me. Cheers LTT.

Linus: This PCIe card is radioactive!
Also Linus: **tosses it on the counter**

I would love to see an LMG office implementation to see a closer-to-real-world example of improvements.

Super cool! I think this is how they beat the CAP Theorem, which was always super-depressing. My understanding of Google's Spanner database is that it uses an atomic clock to ensure Consistency and Atomicity, even when there is Partitioning. CAP Theorem: Pick 2 :-(

Upcoming Fallout games are gonna be interesting with real nuclear parts in your pc!

I had to deal with this recently. We had an API which allows users to retrieve audio files using a token, which is only valid between a set amount of time. The machine the API was on drifted about .5 of a second ahead of time. Which meant when the user took the token to Azure, they were rejected. As the token wasn't going to be enabled for another 10ms. But when the developer was trying to diagnose the problem, stepping through it slowly they couldn't see the issue. We resolved it by instead of generating the token between now and 10 mins in the future. We say between 1 minute ago and 10 in the future. Still though, dealing with databases, and correct information, especially over multiple sites globally, becomes difficult keeping everything in sync and that time stamp because less and less accurate when compared to other centers.

I would LOVE to see you guys do a "setting up our atomic clocks" video. It'd be cool.

This was a fantastic video. I really like videos like this that describe the limitations of technology and how technological developments reduce the limitations to drive capability improvements. Keep it up!

i love the amount of research that linus puts into these videos

I would definitely buy one to try some different projects if they were cheaper. Games that have large asset counts and lots of physics going on for multiplayer seems like something that could really benefit from something like this.

The fact that this was made open source is amazing, world changing stuff.

This was awesome, I love deep dives about timings like this! I setup a GPS Raspberry Pi Timeserver a while back and it was a really fun project.

Now this is actual technological progress. Haven't seen one of those in years besides gimmicks, personally. Glad to witness this event.

Best LTT video in a long time. Very very cool, and I do hope you guys implement a network (even if the benefits are marginal, even if most of our software doesn't take advantage of the increased accuracy).

Gaming aside, I think this would even make regular web browsing feel much snappier. Very excited to see latency benchmarks.

I would absolutely love to watch a video about implementing this on the LTT office network.

It is actually really quite impressive that they managed to miniaturize atomic clocks to such a degree.

I wonder if a card like this would eventually be built into your standard cpus or motherboards eventually. Having a card like this is really cool but if its just in every computer it would effect basically everyone eventually without people having to know about this special card

I love these dives into the new frontiers of tech. Keep it up because it inspires so many people.

This episode was awesome, I like learning new things about computers and it's cool to see some new tech I wasn't already aware of after so many years of watching LTT

This could also be used to enhance the reliability of collaborative programs where you have multiple people making changes to the same file simultaneously.

Something this cool + open source? I was literally cringing at the thought of anybody from FB remoting into my computer, but this guy is legit doing some incredible work. Sparkfun had an atomic clock (cesium) for a while, but I didn't really see the point of having time that accurate until now. This is one of the best LTT videos in a very long time.

"At $1,600, most gamers would buy a 3090 instead" 😂 keep giving them false hope, Linus

How to build a computer gets a tad boring after a while, but this - underneath the hood / behind the scenes - stuff is very cool. How about a video on quantum computing - how it actually works compared to what we all use (memory, processor, etc). Keep it com’n.

It's fascinating to see how the costs have come down since the Atomic pocket watch back in 2013. I expect they'd have to get alot cheaper still to get wide spread acceptance though (possibly integrated into the NIC to avoid the pci-e overhead?)

Id be REALLY curious to see if you could increase performance between the editing computers and the storage servers and the work-from-home editing computers by syncing them with this atomic clock.
How much over head is being lost when accessing video files over the network? Any?

this is actually one of the few new tech innovations that im excited for.

this absolutely _needs_ to happen
even if only for the ability to use the fiber optic networks as grav wave detectors

Jokes aside, this really is pretty cool. I feel like motherboards in the future will just ship with this feature built in

"Tell me if we get signal main screen turn on" has got to be quite the relic these days and I still appreciate it every time I hear it from you Linus.

This is highly impressive the applications are limitless i would go as far as loosely calling this "revolutionary" also the fact that its open source is excellent now things are getting interesting once again in the pc universe. I have a strong feeling this product could have strong applications for astrophysics its very exciting.

This is cool stuff!
Back in the early 1990s, I worked for a life insurance company that had a time server. This '486 PC running Novell Netware, ran a proprietary program that issued time-stamps to all the clients on the network to ensure that the transactions were time stamped accordingly. The resolution was down to a tenth of a second.
Imagine the work of this full-size '486 PC being done on a single PCI board now.

I don't even remember *why*, but I was recently researching the cost of atomic clocks and was surprised by how inexpensive they'd become. And what you're showing off is about half the price of what I found. This seems like one of those things that'll soon be cheap enough that it gets included in SOCs.

LTT has always been informative and funny, but this is actually legit one of the coolest video's I've watched in a while, I always knew about atomic clocks but the fact that they can be used in such World changing ways is mindblowing. I can't wait to see what this will bring in the future.

I like those kind of videos, coll tech things that are fun to watch and learn about. Thanks LTT team, keep the awesome work!

Videos like theese are always so cool, i might not understand everything right away but just by how they are genuinely excited and interested in this tech and where it can do is just so incredible to see!

I was glad to see Ahmad in the video. His work is really important for the future of the internet and scientific discovery and he seems like a super good guy, too!

With 2 of these devices at LTT headquarters could you theoretically do data transfer measurements extremely accurately which would allow for very sophisticated network and data transfer benchmarks for high end equipment? Could you also combine this with uptime calculations to determine network health?

While this is very cool, it gives me some security concerns with regard to possible timing attacks on encryption protocols as well as deanonymisation of users on TOR or similar services.

This was a lot cooler than i was expecting. I wasn't aware how much impact more accurate clocks could have

If this manages to go mainstream, I can think of a magnitude of uses beyond gaming.

In fact a delay was added to the algorithm 'THOR' made by Brad Katsuyama of RBC in the mid 2010's to combat the electronic front running that was happening because of the time/distance fragmentation between all the 44+ stock exchanges in the USA. This didn't always work, but they would delay the order to certain exchanges so they would all hit at the same time when they were purchasing large (like 100k +) share blocks that were split between different exchanges.
When Brad left RBC to build his own stock exchange (Investors Exchange - IEX) they actually built a time delay for the entire market by adding a few hundred KM worth of extra fiber in a shoebox sized box that connected his server in the data center, to the main internet backbone. They achieved with hardware and they were doing with software. It equaled like 350ms or something but virtually removed the ability of HFT to front run that market.

That is really cool. I had no idea that atomic clocks just became orders of magnitude cheaper than they have ever been! Amazing! Crazy to think I could actually buy one...

One of the best videos from LTT! Incredibly interesting and easy to understand

This video is one of the best ones, super informative, funny and really cool. Didn't even feel 14minutes passed...

The clock needs gps to establish an initial timestamp with subsecond accuracy which is why gps is needed. The rubidium just provides significantly slow drift and gives holdover stability when there's loss of gps. Cheaper OXCOs can be used if a gps input is always available.

Radioisotopes are also useful for generating truly random numbers for encryption keys.

I'm interested in this concept just to keep servers in normal sync. NIST keeps changing the host names of their servers, so my scripts periodically break. And NTP servers are shockingly unreliable (crashing, failing to run, etc.).

Very cool. I hadn't thought much about super accurate timing before this. Interesting to think of the implications it could have for manufacturing... Even home 3D printing....

Use it in your house to speed up home automation handling. Could probably make it almost instantaneous rather than having a delay

If this can drastically reduce latency over long distance communication, I would love to see a video using a game streaming service like GeForce now combined with this technology.

Linus: Gets nanosecond accurate timing.
Also Linus: We're still late for the WAN Show.

IBM used to do the same. Everything in IBM UNIX or mainframes were sychronis synchronized to a central clock. Asyncronus used to be better and for many applications it is. But you can use both and eliminate interrupt delays and network collisions etc..

This is gonna be so awesome with game servers when implemented.

This video's content clearly falls into WHAT?!! category. Extremely cool stuff. And clearly one that you might actually not really now yet when this can be important. Using underwater cables to detect gravitational waves sounds like one of those very surprising applications. Use data that is in principle available for almost no additional costs

what happens if you normalize this to be built into every motherboard? would be interesting.

This would be great for your minecraft server. Since I am from Germany and my ping is around 106 I'd be very curious how much performance could be gotten from this device. But did I understand right? I also have to have this device installed in order to benefit from boosts or is it compatible with standard timings?

When Linus watercools this thing, it will require a stack and some graphite rods

I absolutely love this kind of content. Very interesting and exciting

This is the kind of content I like to see on Linus TECH tips. Not just overpowered PCs.

PTP has been used for quite some time in Audio over IP standards, like Dante, AVB, AES67, etc. :)

Hi Linus team. A new video idea, how many routers and wifi networks would it take to make every wifi unusable due to interference?

This same concept is used when slaving a bunch of A/D audio devices (analog digital audio conversion) into one dedicated system. I don't think rubidium is used (in fact I am sure of it, 99% of most prosumer and consumer interfaces use quartz crystal like a wristwatch/clock).
But being able to say that "my 256 channels of AD is clocked with rubidium" would be pretty neat lol

Please implement this. This can only give great results: a faster network and/ or a very entertaining series. And it isn't as expensive as a gold controller 😉

To be precise, submarine fibre optic cables no longer use repeaters, as in, a conversion from optical to electrical to optical signals.
They use Erbium Doped Fibre Amplifiers (EDFAs), which are a pure optical to optical amplification technique (powered by pump lasers at different wavelengths, which are powered by electricity).
As to whether these still fail I'm not sure, they are usually dual redundant pump lasers and they are built with a 25 year lifespan.

I enjoyed this, sounded a lot more like one of my computer science classes than the average hardware enjoyer

Is there scope for this to be integrated into every motherboard natively?
Gamers would be happy to install it into a spare M.2 but it seems pretty fundamental to general computer infastructure in the future!

Seems this would be useful for database replication in a situation where large amounts of data change rapidly.

Would be nice to see that replacing default quartz clock on motherboards.
First models would probably find their way on servers of course, freeing PCIe slot

This is really neat! I am a touring audio engineer and we kind of deal with the same thing with our systems and syncing digital audio between multiple stations and even the PA systems. We use Word Clocks that use Atomic clocks similar to these cards. Having multiple stations that are processing the same source in real time need an external clock source to reference to rather than referencing back to there own processed internal clock source. Trying to have these stations process and reference this internally rather than syncing from a external word clock can create phase relation issues and even complete audio dropouts and very bad noises from a digital source. Latency is everything in the world of live audio.

Fun fact: it is also actually very useful in robotics, in what we call RTOS, or Real Time Operating Systems. These, sometimes, need to be so precise in time, that every single and i do mean every little clock, need to be taken into consideration. For instance, CoBots (colaborative robots) are robots that can share the same working space as that of a human (common robots can't, since sometimes, they can actually crush humann bones as if they were rotten bananas). To do that they need very precise sensor arrays and data processing to estimate just where the dumbass human is, so that the little dumbass human dont get in the way of the mighty bot (like id do often because i seem to always hit everything in my way accidebtally) and get their puny weak weak jelly pathetic skull smashed

This should've been a part of my computer engineering syllabus.

Something doesn't smell right about the claim of 100X speedup just by having super accurate time synchronization. That clock still needs a distribution network, subject to the same signal propagation delays it is meant to compensate for. Still, it's definitely interesting to think about!

So could you use this theoretically to run house in sync instead of the typical master and slave config. If they were all the same clock timing guaranteed basically wouldn't splitting the work between them become super easy?

These have been around for years but the atomic oscillator, drive and time circuits are the most expensive parts and calibration is very expensive.
PTP has been a game changer for synchronising clocks over communication networks.
These clocks are so precise even relativistic effects have to be taken into account such as GPS and other satellites.
Great video.

Y'all gotta show off one of those photon quantum mirror splitter "true random" PCI-E cards. They're SO COOL and very underappreciated.

Ahmad rocks! I had no idea why time accuracy is needed on such a small scale.

We did something along these lines at work to enhance network security. One computer acted as the time standard, and communicated with the Bureau of Standards, and all the other computers that needed access got their time from that one. That way if a computer tried to access our system, but had a wrong time stamp it would be rejected.

i worked with a passive satellite receiver in the Navy that had a time card the size of an ITX motherboard and had an accuracy of 1 second every 1000 years. it was 90s technology and was set by hand.
this is the size of a sound blaster and is at least a couple of orders of magnitude more accurate and can keep track of its own time.
that is absolutely amazing.

I wonder if this technology could be used to optimize the communications between Graphic card, cpu, ram, and drive...

This is so cool just for using a oscilloscope. I am a automotive technician and use a oscilloscope everyday. Love my pico scope... great video

Linus: "There really isn't much in the way of this gaining widespread support."
Also Linus: "Why is this card RADIOACTIVE!?!?"
Also Linus: "Are we really gonna do that? Yeah, I'm not sure about that..."

This technology has huge implications and potential benefits to telemetry from multiple sources that are all time sync’d.
Amazing.
We’ve been looking for this for quite some time…. No pun intended.

This is a huge deal. We're on our way to a world without lag 🙌

I just wanted to say that i like that ltt is covering topics that only remotely aply to the average user as of today but may be groundbreaking in the future

Ya know. Living 30 minutes away from LIGO and hearing you mention it so many times in this video made me really happy. I have like 5 friends that work at the LIGO station. The things they're doing there is awesome.