This is a 54 minute video. I watched about 3 minutes and it seemed like some potentially interesting info wrapped in useless visuals. I thought about downloading and reading the transcript (that's faster than watching videos), but it seems to me that it's another video that would be much better as a blog post. Could someone summarize in a sentence or two? Yes we know about the refresh interval. What is the bypass?
"Tailslayer is a C++ library that reduces tail latency in RAM reads caused by DRAM refresh stalls.
"It replicates data across multiple, independent DRAM channels with uncorrelated refresh schedules, using (undocumented!) channel scrambling offsets that works on AMD, Intel, and Graviton. Once the request comes in, Tailslayer issues hedged reads across all replicas, allowing the work to be performed on whichever result responds first."
FYI if you have a video you can't be bothered watching but would like to know the details you have 2 options that I use (and others, of course):
1. Throw the video into notebooklm - it gives transcripts of all youtube videos (AFAIK) - go to sources on teh left and press the arrow key.
Ask notbookelm to give you a summary, discuss anything etc.
2. Noticed that youtube now has a little Diamond icon and "Ask" next to it between the Share icon and Save icon. This brings up gemini and you can ask questions about the video (it has no internet access). This may be premium only. I still prefer Claude for general queries over Gemini.
> using (undocumented!) channel scrambling offsets that works on AMD, Intel, and Graviton
Seems odd to me that all three architectures implement this yet all three leave it undocumented. Is it intended as some sort of debug functionality or what?
you could however link to the timestamp where that particular explanation starts. i am afraid i don't have time to watch a one hour video just to satisfy my curiosity.
The actual explanation starts a couple minutes later, around https://youtu.be/KKbgulTp3FE?t=1553. The short explanation is performance (essentially load balancing against multiple RAM banks for large sequential RAM accesses), combined with a security-via-obscurity layer of defense against rowhammer.
Not complaining about the particular presenter here, this is an interesting video with some decent content, I don't find the presentation style overly irritating, and it is documenting a lot of work that has obviously been done experimenting in order to get the end result (rather than just summarising someone else's work). Such a goofy elongated style, that is infuriating if you are looking for quick hard information, is practically required in order to drive wider interest in the channel.
But the “ask the LLM” thing is a sign of how off kilter information passing has become in the current world. A lot of stuff is packaged deliberately inefficiently because that is the way to monetise it, or sometimes just to game the searching & recommendation systems so it gets out to potentially interested people at all, then we are encouraged to use a computationally expensive process to summarise that to distil the information back out.
MS's documentation the large chunks of Azure is that way, but with even less excuse (they aren't a content creator needing to drive interest by being a quirky presenter as well as a potential information source). Instead of telling me to ask copilot to guess what I need to know, why not write some good documentation that you can reference directly (or that I can search through)? Heck, use copilot to draft that documentation if you want to (but please have humans review the result for hallucinations, missed parts, and other inaccuracies, before publishing).
The video definitely wouldn't be over 50m if she was targeting views. 11m -15m is where you catch a lot of people repeating and bloviating 3m of content to hit that sweet spot of the algorithm. It's sad you can't appreciate when someone puts passion into a project.
This is the damage AI does to society. It robs talented people of appreciation. A phenomenal singer? Nah she just uses auto tune obviously. Great speech? Nah obviously LLM helped. Besides I don't have time to read it anyway. All I want is the summary.
I don't consider AI to threaten "damage to society" the way you seem to, but I did find it interesting to think about how ridiculously well-produced the video was, and what that might signify in the future.
I kept squinting and scrutinizing it, looking for signs that it was rendered by a video model. Loss of coherence in long shots with continuity flaws between them, unrealistic renderings of obscure objects and hardware, inconsistent textures for skin and clothing, that sort of thing... nope, it was all real, just the result of a lot of hard work and attention to detail.
Trouble is, this degree of perfection is itself unrealistic and distracting in a Goodhart's Law sense. Musicians complain when a drum track is too-perfectly quantized, or when vocals and instruments always stay in tune to within a fraction of a hertz, and I do have to wonder if that's a hazard here. I guess that's where you're coming from? If you wanted to train an AI model to create this type of content, this is exactly what you would want to use as source material. And at that point, success means all that effort is duplicated (or rather simulated) effortlessly.
So will that discourage the next-generation of LaurieWireds from even trying? Or are we going to see content creators deliberately back away from perfect production values, in order to appear more authentic?
Yes, I do want the summary because my time is (also) valuable. There is a reason why book covers have synopses, to figure out whether it's worth reading the book in the first place.
In this case the useful info in the book could be distilled down to the cover blurb.
This video really should have been two videos anyway. One to describe how DRAM works (old hat to some of us nerds, but interesting and new to lots of others), and the second one to explain how she got around the refresh interval. Then nerds could skip the first one completely. In reality the two videos could be about 5 minutes each.
I think Laurie is still trying to develop her style. She's been at it for just a few years and her delivery greatly improved over that time span. Not a fan (yet?), but I've seen a few of her videos from different time periods.
Perhaps she or someone on her team (the camera work suggests at least a +1) thinks that this geeky/ditsy persona gets more clicks. Other successful YTers behave similarly. I don't find it useful or entertaining, but others might.
Having said this, I, myself, would've liked the video to be a bit more succinct
I like the video because I cant read a blog post in the background while doing other stuff, and I like Gadget Hackwrench narrating semi-obscure CS topics lol
this is a thing people do. convince themselves they can consume technical content subconsciously. its now how the brain works though. it will just give you the idea you are following something.
not all technical content is the same, or has the same level of importance. this video does not introduce anything that i need to be able to replicate in my work, so i don't need to catch every detail of it, just grasp the basic concepts and reasons for doing something.
Lots of people will have a show on or something while they're cooking or cleaning or doing other things. Is it worse for it to be interesting technical content with fun other stuff thrown in than if was an episode of Friends or Fraiser or Iron Chef or 9-1-1: Lone Star or The Price is Right?
I guess I'm only allowed to have The Masked Singer on while I make dinner.
FWIW, I like her videos but I usually prefer essays or blog posts in general as they're easier to scan and process at my own rate. It's not about this particular video, it's about videos in general.
I get a similar feeling for when friends send me 2minute+ Instagram reels, it's as if my brain can't engage with the content. I'd much rather read a few paragraphs about the topic, and It'd probably take less time too.
Same; thanks to modern technology, videos can be transcribed and translated into blog posts automatically though. I wish that was a default and / or easier to find though.
For years I've been thinking "I should watch the WWDC videos because there's a lot of Really Important Information" in there, but... they're videos. In general I find that I can't pay attention to spoken word (videos, presentations, meetings) that contain important information, probably because processing it costs a lot more energy than reading.
But then I tune out / fall asleep when trying to read long content too, lmao. Glad I never did university or do uni level work.
You're saying that the audio channel of that video has the useful information all by itself. The video channel, which consumes most of the bandwidth, is useless. You could go a little further and say about 80% of the 54 minute audio is also useless, and it could be cut to maybe 10 minutes. Keep going and say to post it as text instead of audio, so you can read it in 2 minutes. Now you don't have to put it in the background.
Update: found the bypass via the youtube blurb: https://github.com/LaurieWired/tailslayer
"Tailslayer is a C++ library that reduces tail latency in RAM reads caused by DRAM refresh stalls.
"It replicates data across multiple, independent DRAM channels with uncorrelated refresh schedules, using (undocumented!) channel scrambling offsets that works on AMD, Intel, and Graviton. Once the request comes in, Tailslayer issues hedged reads across all replicas, allowing the work to be performed on whichever result responds first."