News for hackers. Stuff that matters.

wholehog

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Saturday December 07, 2024 @10:59AM (#42350569)
If someone tries to run your method but messes it up, and then accuses you of fraud when the results don't match their expectations, I'm not sure they're entitled to a neutral tone in response.

Maybe you're right, and a more neutral tone would have been effective! I think it's just that Jeff is just really done with this.

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Saturday December 07, 2024 @10:38AM (#42350433)
I think the pre-trained checkpoint uses the same 20 TPU blocks as the original paper, but it probably isn't the exact-same checkpoint, as the paper itself is from 2020/2021.
Re:Jeff Dean Responds to EDA Industry about AlphaChip on Saturday December 07, 2024 @10:28AM (#42350389)
As Andrew Kahng was one of the co-authors of Cheng et al., all of the issues with his reproduction still matter here. The Nature paper went through an investigation and second round of peer review.

AlphaChip is used to make real chips in production. Google publicly announced its use in multiple generations of TPUs and Axion CPUs, and MediaTek said they've built on it as well.

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Saturday December 07, 2024 @10:16AM (#42350302)
Three generations of TPU, Axion (ARM-based CPU), various other chips at AlphaBet, MediaTek's usage...
Re:Jeff Dean Responds to EDA Industry about AlphaChip on Saturday December 07, 2024 @10:14AM (#42350288)
The UCSD paper didn't run the Nature method correctly, so I don't see how you can draw this conclusion.

From Jeff's tweet:

"In particular the authors did no pre-training (despite pre-training being mentioned 37 times in our Nature article), robbing our learning-based method of its ability to learn from other chip designs, then used 20X less compute and did not train to convergence, preventing our method from fully learning even on the chip design being placed."

As for Chatterjee's paper, "We provided the committee with one-line scripts that generated significantly better RL results than those reported in Markov et al., outperforming their “stronger” simulated annealing baseline. We still do not know how Markov and his collaborators produced the numbers in their paper."

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Wednesday December 04, 2024 @11:03PM (#42324843)
"Prior to publication of Cheng et al., our last correspondence with any of its authors was in August of 2022 when we reached out to share our new contact information."

You don't stop being the corresponding authors of a paper when you change companies, and whatever "unclear circumstances" you imagine took place when they left, they were also re-hired later, which a company would only do if they were in good standing.

In any case, those "Google contacts" also expressed concerns with how Cheng et al. were doing their study, which they ignored:

3.4 Cheng et al.’s Incorrect Claim of Validation by Google Engineers

Cheng et al. claimed that Google engineers confirmed its technical correctness, but this is untrue. Google engineers (who were not corresponding authors of the Nature paper) merely confirmed that they were able to train from scratch (i.e. no pre-training) on a single test case from the quick start guide in our open-source repository. The quick start guide is of course not a description of how to fully replicate the methodology described in our Nature paper, and is only intended as a first step to confirm that the needed software is installed, that the code has compiled, and that it can successfully run on a single simple test case (Ariane).

In fact, these Google engineers share our concerns and provided constructive feedback, which was not addressed. For example, prior to publication of Cheng et al., through written communication and in several meetings, they raised concerns about the study, including the use of drastically less compute, and failing to tune proxy cost weights to account for a drastically different technology node size.

The Acknowledgements section of Cheng et al. also lists the Nature corresponding authors and implies that they were consulted or even involved, but this is not the case. In fact, the corresponding authors only became aware of this paper after its publication.

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @08:06PM (#42302070)
"These major methodological differences unfortunately invalidate Cheng et al.’s comparisons with and conclusions about our method. If Cheng et al. had reached out to the corresponding authors of the Nature paper[8], we would have gladly helped them to correct these issues prior to publication[9].

[8] Prior to publication of Cheng et al., our last correspondence with any of its authors was in August of 2022 when we reached out to share our new contact information.

[9] In contrast, prior to publishing in Nature, we corresponded extensively with Andrew Kahng, senior author of Cheng et al. and of the prior state of the art (RePlAce), to ensure that we were using the appropriate settings for RePlAce."

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @01:51PM (#42299100)
I mean, I think second is still "one of the first?" And, no offense to this project, but I don't know of it being used in a real industrial setting, whereas AlphaChip was used in TPU.
Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @01:44PM (#42299016)
So much wasted time.

He even ran a study internally (with Markov), but, as the AlphaChip authors describe:

In 2022, it was reviewed by an independent committee at Google, which determined that “the claims and conclusions in the draft are not scientifically backed by the experiments” [33] and “as the [AlphaChip] results on their original datasets were independently reproduced, this brought the [Markov et al.] RL results into question” [33]. We provided the committee with one-line scripts that generated significantly better RL results than those reported in Markov et al., outperforming their “stronger” simulated annealing baseline. We still do not know how Markov and his collaborators produced the numbers in their paper. (https://arxiv.org/pdf/2411.10053)

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @01:37PM (#42298951)
> Does the EDA ecosystem support a similarly open culture of benchmarking for commercial tools?

If only. The comparison in Cheng et al. is the only public comparison with CMP that I can recall, and it is pretty suss that this just so happens to be a very pro-commercial-autoplacer study. (And, Cheng et al. have cited 'licensing agreements' as a reason for not giving out the synthesized netlists necessary to reproduce their results.)

Reminded a bit of Oracle. They likewise used to (and maybe still?) prohibit any benchmarking of their database software against that of another provider. This seems to be a common move for solidifying a strong market position.

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @01:24PM (#42298836)
> Did they mess up when they did not pre-train or they followed the "steps" described in the original repo and tried to get a fair reproduction?

The Circuit Training repo was just going through an example. It is common for an open-source repo to describe simple examples for testing / validating your setup --- that does not mean this is how you should get optimal results in general. The confusion may stem from their statement that, in this example, they produced results that were comparable with the pre-trained results in the paper. This is clearly not a general repudiation of pre-training.

If Cheng et al. genuinely felt this was ambiguous, they should have reached out to the corresponding authors. If they ran into some part of the repo they felt they had to "reverse-engineer", they should have asked about that, too.

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @01:06PM (#42298651)
Are you really suggesting that the TPU team does not stand behind the graphs in Google's own blog post? And that MediaTek does not stand behind their quoted statement?
Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @12:44PM (#42298447)
His original complaint being dismissed matters because it suggests that he was fishing around for a complaint that was valid, and that perhaps his primary motivation was to get money out of Google.

Legal nitpick - you can get away with alleging pretty much whatever you want in a legal complaint. You can't even be sued for defamation if it turns out later you were lying.

Jeff Dean isn't saying that Cheng et al. should be unpublished; he's saying that they didn't run the method the same way. It is perfectly fine for someone to try changing the method and report what they found. What's not fine is to claim that this means that Google was lying in their study.

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @12:34PM (#42298354)
> it might have a harder time with a chip designed by a third party (further from its pre-training).

Then they could pre-train on chips that are in-distribution for that task.

See also section 3.1 of their response paper, where they describe a comparison against commercial autoplacers: https://arxiv.org/pdf/2411.10053

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @01:35AM (#42293693)
They also changed the ratio of RL experience collectors to GPU workers (~1/20th the RL experience collectors, 1/2 the GPUs). I don't know what impact that has --- maybe each GPU episode has less experience? Maybe that makes for an effectively small batch size and therefore more chaotic training? But either way, why change things when you can just match them exactly?
Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @01:31AM (#42293676)
> published a crappy article in Nature because it would never have passed editorial muster at something like DAC or an IEEE journal and now have to browbeat other people who are calling them out on it.

I don't think it's easier to get into DAC / an IEEE journal than Nature.

Their human baseline was the TPU physical design team, with access to the best available tools: rdcu.be/cmedX

and this is still the baseline to beat in order to get used in production, which has happened for multiple generations of TPU.

TPU is export controlled and super confidential -- multi-billion dollar IP! -- so I don't see raw data coming out anytime soon.

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @01:25AM (#42293649)
Pre-training is just training on multiple chips.

"If Cheng et al. had reached out to the corresponding authors of the Nature paper, we would have gladly helped them to correct these issues prior to publication" (https://arxiv.org/pdf/2411.10053)

That's how you actually do a reproduction study - you reach out to the corresponding authors and make sure you do everything exactly the same. But at this point, it's hard to imagine the AlphaChip folks having much patience with them.

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @01:15AM (#42293605)
That is definitely a cool project, but I don't see how it contradicts "one of the first RL methods deployed to solve a real-world engineering problem". "One of the first" does not mean literally the first ever.
Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @01:10AM (#42293578)
> The whole publication process seems dishonest, starting from publishing in Nature (why not ISCCC or something similar?)

Why would you publish in ISCCC when you can get into Nature?

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @12:49AM (#42293472)
You're linking to his amended complaint - his original complaint was thrown out because it alleged things like "Google's motto is don't be evil, but they were evil, thus defrauding me."

According to a Google investigator's sworn statement, he admitted that he didn't have evidence to suspect the AlphaChip authors of fraud: "he stated that he suspected that the research being conducted by Goldie and Mirhoseini was fraudulent, but also stated that he did not have evidence to support his suspicion of fraud".

I feel like if someone persistently makes unsupported allegations of fraud, they should not be surprised if they get shown the door.

The comparison against commercial autoplacers might be this one (from That Chip Has Sailed - https://arxiv.org/pdf/2411.10053):

"In May of 2020, we performed a blind internal study[12] comparing our method against the latest version of two leading commercial autoplacers. Our method outperformed both, beating one 13 to 4 (with 3 ties) and the other 15 to 1 (with 4 ties). Unfortunately, standard licensing agreements with commercial vendors prohibit public comparison with their offerings."

[12] - "Our blind study compared RL to human experts and commercial autoplacers on 20 TPU blocks. First, the physical design engineer responsible for placing a given block ranked anonymized placements from each of the competing methods, evaluating purely on final QoR metrics with no knowledge of which method was used to generate each placement. Next, a panel of seven physical design experts reviewed each of the rankings and ties. The comparisons were unblinded only after completing both rounds of evaluation. The result was that the best placement was produced most often by RL, followed by human experts, followed by commercial autoplacers."

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @12:41AM (#42293431)
What are you even talking about? Jeff had a hand in TPU, which is so successful that all other AI companies are trying to clone this project and spin up their own efforts to make custom AI chips.
Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @12:39AM (#42293421)
> Some would say he got taken for a ride by a young charismatic grifter and is now in too deep to back out.

Was the TPU physical design team also taken in? And also MediaTek? And also TF-Agents, which publicly said they re-produced the AlphaChip method and results exactly?

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @12:35AM (#42293411)
See my comment above - the Nature authors already did this, and tried a huge hyperparameter sweep for SA, and RL still won.

See appendix of the Nature article: rdcu.be/cmedX

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Monday December 02, 2024 @12:34AM (#42293405)
> However, if we wanted to rigorously benchmark AlphaChip against simulated annealing or other floorplanning algorithms, we have to afford the same compute and runtime budget to each algorithm.

The Nature authors already presented such a study in their appendix:

"To make comparisons fair, we ran 80 SA experiments sweeping different hyperparameters, including maximum temperature (10^−5, 3 × 10^−5, 5 × 10^−5, 7 × 10^-5, 10^−4, 2 × 10^−4, 5 × 10^−4, 10^−3), maximum SA episode length (5 × 10^4, 10^5) and seed (five different random seeds), and report the best results in terms of proxy wirelength and congestion costs in Extended Data Table 6"

Non-paywalled Nature article link: rdcu.be/cmedX

Re:Jeff Dean Responds to EDA Industry about AlphaChip on Saturday November 30, 2024 @11:58PM (#42286298)
We're talking 16 GPUs for ~6 hrs for inference, and 48 hrs for pre-training. This is not an exorbitant amount of compute.

A GPU costs $1-2/hr on the cloud market. So, ~$100-200 for inference, and ~$800-1600 for pre-training, which amortizes across chips. Cloud prices are an upper bound -- most CS labs will have way more than this available on premises.

In an industry context, these costs are completely dwarfed by the rest of the chip design process. (For context, the licensing costs alone for most commercial EDA software are in the millions of dollars.)

Somehow annoying that Senator Warner gave the story to NYT and WaPo, even though WSJ broke the story:

"The hackers behind the infiltration of U.S. telecom infrastructure are known to Western intelligence agencies as Salt Typhoon, and this particular breach of U.S. equipment was first reported in early October by the Wall Street Journal. But Sen. Mark Warner, a Democrat from Virginia, spoke with the Washington Post and New York Times this week to warn the public that this is so much worse than we initially thought, dubbing it “the worst telecom hack in our nation’s history.” And those articles based on Warner’s warnings were published late Thursday."

WSJ: https://www.wsj.com/tech/cybersecurity/u-s-wiretap-systems-t...

Re:Substack is the real Twitter/X replacement? on Saturday November 23, 2024 @01:14AM (#42219469)
But how am I supposed to doomscroll on Substack?

Older »