Live data from Hacker News

How AlphaChip transformed computer chip design

deepmind.google

101–110 of 215 posts

Re: How AlphaChip transformed computer chip design

#101
post #84
post #36

I'm pretty sure Cadence and Synopsys have both released reinforcement-learning-based placing and floor planning tools. How do they compare...?

They don't. You cannot compare reality (Cadence, Synopsys) with hype (Google).

So you're basically saying that Google should have used existing tools to layout their chip designs, instead of their ML solution, and that these existing tools would have produced even better chips than the ones they are actually manufacturing?

Re: How AlphaChip transformed computer chip design

#102

Earlier quoted context omitted.

The original paper reports P&R metrics (WNS, TNS, area, power, wirelength, horizontal congestion, vertical congestion) - https://www.nature.com/articles/s41586-021-03544-w (no paywall): https://www.cl.cam.ac.uk/~ey204/teaching/ACS/R244_2021_2022/...

From what I saw in the rebuttal papers, the Google cost-function is wirelength based. You can still get good TNS from that if your timing is very simplistic -- or if you choose your benchmark carefully.

They optimize using a fast heuristic based on wirelength, congestion, and density, but they evaluate with full P&R. It is definitely interesting that they get good timing without explicitly including it in their reward function!

Re: How AlphaChip transformed computer chip design

#103
post #64

Earlier quoted context omitted.

why do you think that?

Far more people / companies are designing PCBs than there are designing custom chips.

I think the real value would be in ease of use. I imagine the top N chip creators represent a fair bit of the marginal value in pushing the state of the art forward. E.g., for hobbyists or small shops, there's likely not much value in tiny marginal improvements, but for the big ones it's worth the investment.

Re: How AlphaChip transformed computer chip design

#104
post #82

Earlier quoted context omitted.

The problem is that the competition (our current von neumann architecture) has billions of dollars of R&D per year invested. Better architectures without the yearly investment train will no longer be better quite quickly. You would need to be 100x to 1000x better in order to pull the investment train onto your tracks. Don’t has been impossible for decades. Even so, I think we will see such a change in my lifetime. AI…

I think it's just ignorance and timidity on the part of investors. Memristor or memory-computing startups are surely the next trend in investing within a few years. I don't think it's necessarily demand or any particular calculation that makes things happen. I think people including investors are just herd animals. They aren't enthusiastic until they see the herd moving and then they want in.

I don't think it's ignorant to not invest in something that has a decade long path towards even having a market, much less a large market.

Re: How AlphaChip transformed computer chip design

#105
post #104
post #82

Earlier quoted context omitted.

I think it's just ignorance and timidity on the part of investors. Memristor or memory-computing startups are surely the next trend in investing within a few years. I don't think it's necessarily demand or any particular calculation that makes things happen. I think people including investors are just herd animals. They aren't enthusiastic until they see the herd moving and then they want in.

I don't think it's ignorant to not invest in something that has a decade long path towards even having a market, much less a large market.

I have seen at least one experiment running a language model or other neural network on (small scale) memory-based computing substrates. That suggests less than 1-2 years to apply them immediately to existing tasks once they are scaled up in terms of compute capacity.

Re: How AlphaChip transformed computer chip design

#106
post #48

This work from Google (original Nature paper: https://www.nature.com/articles/s41586-021-03544-w ) has been credibly criticized by several researchers in the EDA CAD discipline. These papers are of interest: - A rebuttal by a researcher within Google who wrote this at the same time as the "AlphaChip" work was going on ("Stronger Baselines for Evaluating Deep Reinforcement Learning in Chip Placement"): http://47.190.8…

It seems like this is multiple parties pursuing distinct arguments. Is Google saying that this technique is applicable in the way that the rebuttals are saying it is not? When I read the paper and the update I did not feel as though Google claimed that it is general, that you can just rip it off and run it and get a win. They trained it to make TPUs, then they used it to make TPUs. The fact that it doesn't optimize w…

Good question. It's not just ibm14, but everything people outside Google tried shows that RL is much worse than prior methods. NVDLA, BlackParrot, etc. There is a strong possibility that Google pre-trained RL on certain TPU designs then tested in them, and submitted to Nature.

Re: How AlphaChip transformed computer chip design

#107

Some interesting context on this work: 2 researchers were bullied to the point of leaving Google for Anthropic by a senior researcher (who has now been terminated himself): https://www.wired.com/story/google-brain-ai-researcher-fired... They must feel vindicated by their work turning out to be so fruitful now.

It's actually not clear who was bullied. The two researchers ganged up on Chatterjee and got him fired because he used the word "fraud" - wrongful termination of a whistleblower. Only recently Google settled with Chatterjee for an undisclosed amount.

Re: How AlphaChip transformed computer chip design

#108

Earlier quoted context omitted.

The original paper reports P&R metrics (WNS, TNS, area, power, wirelength, horizontal congestion, vertical congestion) - https://www.nature.com/articles/s41586-021-03544-w (no paywall): https://www.cl.cam.ac.uk/~ey204/teaching/ACS/R244_2021_2022/...

From what I saw in the rebuttal papers, the Google cost-function is wirelength based. You can still get good TNS from that if your timing is very simplistic -- or if you choose your benchmark carefully.

The odd thing is that they don't compute timing in RL, but claim that somehow TNS and WNS improved. Does anyone believe this? With five circuits and three wins, the results are a coin toss.

Re: How AlphaChip transformed computer chip design

#109

Some interesting context on this work: 2 researchers were bullied to the point of leaving Google for Anthropic by a senior researcher (who has now been terminated himself): https://www.wired.com/story/google-brain-ai-researcher-fired... They must feel vindicated by their work turning out to be so fruitful now.

Vindicated indeed. The senior researcher and others on the project were bullied for raising concerns of fraud by the two researchers [1]. They filed a lawsuit against Google that has a lot of detailed allegations of fraud [2].

[1] https://www.theregister.com/AMP/2023/03/27/google_ai_chip_pa...

[2] https://regmedia.co.uk/2023/03/26/satrajit_vs_google.pdf

Post reply on HN