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DRAM has a design flaw from 1966. I bypassed it [video]

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Re: DRAM has a design flaw from 1966. I bypassed it [video]

#91

Post by bronlund »

ahoka wrote: post #89
bronlund wrote: post #79

Earlier quoted context omitted.

For an HFT firm, RAM cost is a non-issue. Even the tiniest improvement in latency can result in millions of dollars of extra profit. They can octuple their RAM usage and still make a killing. I bet Citadel already has reached out to Laurie :)

[flagged]

This is not a problem which needed to be fixed, it's an improvement in efficiency - though a costly one. We are talking about a company which do make their own custom microchips so you could very well be right, but it may also be that they weren't even aware this was possible.

Citadel executes trades in about 10 microseconds, so a 500 nanosecond reduced execution time is a 5% improvement. For a company which executes trades for hundreds of billions a day, this translates to real money.

Your sarcasm indicates that you have no clue as to how important such an improvement can be for some actors. Some do though; the repo has almost 100 forks and 2K stars after just two days.

Re: DRAM has a design flaw from 1966. I bypassed it [video]

#92

Post by zozbot234 »

foltik wrote: post #6

Love the format, and super cool to see a benchmark that so clearly shows DRAM refresh stalls, especially avoiding them via reverse engineering the channel layout! Ran it on my 9950X3D machine with dual-channel DDR5 and saw clear spikes from 70ns to 330ns every 15us or so. The hedging technique is a cool demo too, but I’m not sure it’s practical. At a high level it’s a bit contradictory; trying to reduce the tail late…

> clear spikes from 70ns to 330ns

Isn't that rather trivial though as a source of tail latency? There's much worse spikes coming from other sources, e.g. power management states within the CPU and possibly other hardware. At the end of the day, this is why simple microcontrollers are still preferred for hard RT workloads. This work doesn't change that in any way.

Re: DRAM has a design flaw from 1966. I bypassed it [video]

#96

Post by Cthulhu_ »

derbOac wrote: post #84
svrtknst wrote: post #50

Earlier quoted context omitted.

Unnecessarily negative imo. 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

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.

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.

Re: DRAM has a design flaw from 1966. I bypassed it [video]

#97

Post by gosub100 »

throwaway81523 wrote: post #32
kreelman wrote: post #4

This is very much worth watching. It is a tour de force. Laurie does an amazing job of reimagining Google's strange job optimisation technique (for jobs running on hard disk storage) that uses 2 CPUs to do the same job. The technique simply takes the result of the machine that finishes it first, discarding the slower job's results... It seems expensive in resources, but it works and allows high priority tasks to run…

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? Up…

Your comment was several paragraphs, and I am busy so I can't read it all. Can you summarize what you are asking for, I might be able to help later.

Re: DRAM has a design flaw from 1966. I bypassed it [video]

#98

Post by JuniperMesos »

kelsolaar wrote: post #58
throwaway81523 wrote: post #32

Earlier quoted context omitted.

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? Up…

The video could be a shorter, some of the goofiness might not please the most pressed people but that is also what makes it fresh and stand out.

There was nothing goofy about the NERV-logo coffee mug, that was extremely serious business.

Re: DRAM has a design flaw from 1966. I bypassed it [video]

#99

Post by gosub100 »

dspillett wrote: post #66
satvikpendem wrote: post #35

Earlier quoted context omitted.

Just use the Ask button on YouTube videos to summarize, that's what it's for.

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…

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.

Re: DRAM has a design flaw from 1966. I bypassed it [video]

#100

Post by [deleted] »

fc417fc802 wrote: post #56
guenthert wrote: post #48

Earlier quoted context omitted.

No, something is funny here. In the previous submission ( https://news.ycombinator.com/item?id=47680023 ) the only (competently) criticizing comment (by jeffbee) was downvoted into oblivion/flagged.

Well he veered off of the technical and into the personal so I'm not surprised it's dead. But yeah something feels weird about this comment section as a whole but I can't quite put my finger on it. I think rather than AI it reminds me of when (long before AI) a few colleagues would converge on an article to post supportive comments in what felt like an attempt to manipulate the narrative and even at concentrations th…

[deleted]
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