CERN uses ultra-compact AI models on FPGAs for real-time LHC data filtering • Hacker News Board

Re: CERN uses ultra-compact AI models on FPGAs for real-time LHC data filtering

#121

Post by archermarks » Sat, Mar 28, 2026, 5:26 PM UTC

isotypic wrote: post #107

archermarks wrote: post #102

Earlier quoted context omitted.

I didn't know that! Do you have any references that go into more depth here? I'd be curious how the architect and train it.

I believe D. A. Jimenez and C. Lin, "Dynamic branch prediction with perceptrons" is the paper which introduced the idea. It's been significantly refined since and I'm not too familiar with modern improvements, but B. Grayson et al., "Evolution of the Samsung Exynos CPU Microarchitecture" has a section on the branch predictor design which would talk about/reference some of those modern improvements.

Thank you, I'll give them a read.

Re: CERN uses ultra-compact AI models on FPGAs for real-time LHC data filtering

#122

Post by stefanpie » Sat, Mar 28, 2026, 5:32 PM UTC

chsun wrote: post #112

One of the authors (of one of the two models, not this particular paper) here. Just a clarification, these models are *not* burned into silicon. They are trained with brutal QAT but are put onto fpgas. For axol1tl, the weights are burned in the sense that the weights are hard-wired in the fabric (i.e., shift-add instead of conventional read-muk-add cycle), but not on the raw silicon so the chip can be reprogrammed. T…

Very cool to see you work! Early in my PhD I did some work with GNN accelerators on FPGAs (which I think later ended up in some form as a colab with some CERN or Fermilab folks) and have chatted a bit in the past with the FastML, HLS4ML, and HEP folks.

I have since pivoted a lot of my PhD work (still related the HLS and EDA). But I wonder what is the current main limitation/challenges of building these trigger systems in hardware today. For example, in my mind it seems like the EDA and tooling can be a big limitation such as reliance on commercial HLS tools which can be buggy, hard to use, and hard to debug. From experience, this makes it harder to build different optimized architectures in hardware or build co-design frameworks without having high HLS expertise or putting in a lot of extra engineering/tooling effort. Also tool runtimes make the design and debug cycle longer, especially if you are trying to DSE on post-implementation metrics since you bring in implementation tools as well.

But I might be way off here and the real challenges are with other aspects beyond the tools.

Re: CERN uses ultra-compact AI models on FPGAs for real-time LHC data filtering

#123

Post by Create » Sat, Mar 28, 2026, 5:34 PM UTC

jurschreuder wrote: post #77

I've got news for you, everybody with a modern cpu uses this, which use a perceptron for branch prediction.

Other news, is that HEP has used FPGAs for L0 triggers (amongst others) for decades. These always had a diverse selection criteria in their algorithms, event filters, suppression, weights etc. And just mentioning, that some custom radhard simple readout silicon from the likes of STM isn't any news either.

And for historians: Delphi people (amongst others) had papers on Higgs selection using (A)NN from LEP data (overfit :) , obviously without the 5 sigma. It was an argument for LHC.

Dear downvoters/shadowbanners: do your homework.

Re: CERN uses ultra-compact AI models on FPGAs for real-time LHC data filtering

#124

Post by aj7 » Sat, Mar 28, 2026, 5:35 PM UTC

I wonder if it is a PhD thesis to prove that the data prefiltering doesn’t bias the results.

Re: CERN uses ultra-compact AI models on FPGAs for real-time LHC data filtering

#125

Post by ozim » Sat, Mar 28, 2026, 5:47 PM UTC

idiotsecant wrote: post #80

ninjagoo wrote: post #43

Earlier quoted context omitted.

> I'm half expecting to see "AI model" appearing as stand-in for "linear regression" at this point in the cycle. Already the case with consulting companies, have seen it myself

Some career do-nothing-but-make-noise in my organization hired a firm to 'Do AI' on some shitty data and the outcome was basically linear regression. It turns out that you can impressive executives with linear regression if you deliver it enthusiastically enough.

Not everyone knows everything so knowledge is the new oil.

I do know about linear regression even had quite some of it at university.

But I still wouldn’t be able to just implement it on some data without good couple days to weeks of figuring things out and which tools to use so I don’t implement it from scratch.

Re: CERN uses ultra-compact AI models on FPGAs for real-time LHC data filtering

#126

Post by hrmtst93837 » Sat, Mar 28, 2026, 5:49 PM UTC

quijoteuniv wrote: post #16

A bit of hype in the AI wording here. This could be called a chip with hardcoded logic obtained with machine learning

[flagged]

Re: CERN uses ultra-compact AI models on FPGAs for real-time LHC data filtering

#127

Post by andromaton » Sat, Mar 28, 2026, 5:52 PM UTC

jurschreuder wrote: post #77

I've got news for you, everybody with a modern cpu uses this, which use a perceptron for branch prediction.

Indeed, some examples:

https://news.ycombinator.com/item?id=12340348 Neural network spotted deep inside Samsung's Galaxy S7 silicon brain (2016)

https://ieeexplore.ieee.org/document/831066 Towards a high performance neural branch predictor (1999)

Re: CERN uses ultra-compact AI models on FPGAs for real-time LHC data filtering

#128

Post by jeffreygoesto » Sat, Mar 28, 2026, 6:45 PM UTC

quantum_state wrote: post #66

CERN has been doing HEP experiments for decades. What did it use before the current incarnation of AI? The AI label seems to be more marketing and superficial than substantial. It’s a bit sad that a place like CERN feels the need to make it public that it is on the bandwagon.

https://madoc.bib.uni-mannheim.de/809/ is one of a gazillion papers you can find with ancient technology called web search.

Re: CERN uses ultra-compact AI models on FPGAs for real-time LHC data filtering

#129

Post by jeremie_strand » Sat, Mar 28, 2026, 7:14 PM UTC

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Re: CERN uses ultra-compact AI models on FPGAs for real-time LHC data filtering

#130

Post by Create » Sat, Mar 28, 2026, 7:23 PM UTC

dguest wrote: post #111

danparsonson wrote: post #64

Earlier quoted context omitted.

Could they.... have someone else do it for them?

CERN doesn't build everything CERN uses: - FPAGs like this one are generally COTS. - All the experiments use GPUs which come straight from the vendors. - Most of the computing isn't even on site, it's distributed around the world in various computing centers. Yes they also overflow into cloud computing but various publicly funded datacenters tend to be cheaper (or effectively "free" because they were allocated to CER…

CERN builds almost next to nothing anymore. Half a century ago they really did do RF cavities, cooling, electronics etc. Not anymore. It is either COTS (DELL, Alterra etc.) or chiefly vendor bidding for some custom parts. Much like what NASA (from Rocketdyne, TRW to Boeing and SpaceX) or copycat ESA (Airbus, DLR, BAE's suppliers) does today.

It is a project bureau. Everything is essentially outsourced, leaving a management shell institute to parade for VIPs. Actually they are close to completely forgetting what they already knew in the hard sciences domain.