HNHacker News
TopNewBestAskShowJobs

zhemao

1,723 karma · joined August 3, 2011

ASIC Design Engineer Computer Architecture PhD grad

Website: http://zhehaomao.com/

Github: https://github.com/zhemao

submissionscomments
zhemao··on TinyTinyTPU: 2×2 systolic-array TPU-style matrix-multiply unit deployed on FPGA
TPUs aren't transformer ASICs. The Ironwood TPU that Gemini was trained on was designed before LLMs became popular with ChatGPT's release. The architecture was general enough that it ended up being efficient for LLM training.

A special-purpose transformer inference ASIC would be like Etched's Sohu chip.

zhemao··on I should have loved electrical engineering
In computer architecture / digital ASIC design there's zero control theory. There's not much mathematics in general.
zhemao··on I should have loved electrical engineering
I had a similar starting point to the author but ended up in totally the opposite direction, haha. Took computer engineering in undergrad and did well in both CS and EE courses. My first job was as an SDE at AWS but I hated it. Went back to school for EE, got a PhD, and started working as an ASIC designer, which I'm still doing today.

It's definitely the case that there's a bigger jump from school project to actually useful product for EE than for CS. But now that we have affordable but decently featured FPGA boards, the barrier is much lower than before, at least for digital design.

zhemao··on I should have loved electrical engineering
No? There's plenty of overlap. I studied computer engineering in undergrad, which is similar to the author's original major. There are a lot of subjects that straddle the boundary, like computer architecture, embedded systems, and digital signal processing.

Obviously yes, if you're doing heavy analog/power/RF stuff you're going to be pretty far from software, but EE is a really broad field.

zhemao··on Jackie Chan’s Plan to Keep Kicking Forever
Yeah, New Police Story was weirdly dark.

Police Story 1-4 were all good fun. Not really for kids though. Plenty of bawdy jokes and innuendo.

zhemao··on Facebook is 'silencing' Rohingya Muslim reports of 'ethnic cleansing'
And how open is the administration to taking in Rohingya refugees who've been displaced by the violence?
zhemao··on Facebook is 'silencing' Rohingya Muslim reports of 'ethnic cleansing'
> the Buddhists didn't woke up one day and decided to commit genocide

Germans didn't wake up one day in the 1930s and decide to exterminate the Jews either. That doesn't mean the Jews were at all to blame for their persecution.

zhemao··on The New Preschool Is Crushing Kids (2016)
> What ideas have parents come up with to make it "feel" like there's more unstructured play time for kids during the school year?

Uh maybe, I don't know, actually giving them more unstructured play time? Schools have been drastically cutting back on mid-day recess and other types of "free time".

zhemao··on In Defense of Amy Wax’s Defense of Bourgeois Values
Thank you. I wondered if anyone else could see why the original essay is so ridiculous. It assumes that bad culture is the cause of poverty, and not the other way around. It's pretty obvious that the decision to get married and stay married is affected by material conditions. One consequence of the decline in manufacturing jobs is that less-educated men have pretty low employment rates. Since they can't hold down a stable job and be the primary breadwinner (as "bourgeois culture" expects them to), there's little reason for them to stick around (or for their partners to keep them around). This also explains the data Haidt and his group turned up on the correlation between parents' marriage status and children's future success. The couples that managed to stay together were the ones that had a better financial/employment situation. There's no reason to believe that a deadbeat dad would improve his child's future competitiveness that much just by staying married to the child's mother.

There's also the fact that single moms on welfare would lose their benefits if they married the father of their children. As one astute internet commenter on a similar article remarked, "Only an ivory tower egghead could think that poor people don't make rational economic decisions."

zhemao··on In Defense of Amy Wax’s Defense of Bourgeois Values
Pretty sure GP means the mass emigration of Europeans to North America in the 19th and early 20th centuries.
zhemao··on Lu Ban's axe and working with your Chinese suppliers
> places where people aren't getting paid to innovate but rather are there to do a 9-5 job, there is little (and, in many cases, negative) incentive culturally to think outside the box and push the envelope

That's pretty much every country, including the US. Even many Silicon Valley companies are this way.

zhemao··on Lu Ban's axe and working with your Chinese suppliers
Samsung is a strange choice of example. It also mostly follows a "well made clone" business model and Korean work culture isn't much different from Chinese.
zhemao··on Airbnb’s ban of Nazis in Charlottesville sets an important standard
> Does that same freedom exist for private entities that don't want to bake cakes for gay couples?

I think sexuality should be a protected class. I do not think neo-Nazis or White supremacists should be a protected class. But in the case of the wedding cake, I think it would be fine for bakers, caterers, or photographers to refuse to work at a gay wedding, an event they consider immoral. If a customer happened to be a neo-Nazi and was booking a vacation stay, I doubt AirBnB would have cared. It was the fact that they were using the service to book accommodations for the rally that caused the company to cancel their booking.

> That is why you need to defend the principle, even if you don't like the specifics of what you are defending, and is why, for example, the ACLU is defending Milo

The ACLU is defending Milo from government suppression of his speech. I agree with the principle they are defending. This is not the same as a private entity deciding not to do business with him. The ACLU will not, for instance, help him sue Simon & Schuster for cancelling his book deal.

zhemao··on Airbnb’s ban of Nazis in Charlottesville sets an important standard
Religion, race, gender, etc. are protected classes. Political ideology is not.
zhemao··on Airbnb’s ban of Nazis in Charlottesville sets an important standard
Despite the existence of laws criminalizing holocaust denial and displaying Nazi symbols, Germany still has holocaust deniers and neo-Nazis. Criminalizing speech isn't a very effective way of diminishing it.
zhemao··on Airbnb’s ban of Nazis in Charlottesville sets an important standard
Yes, the 1st amendment protects freedom of association. That is, the freedom of private entities to not do business with Nazis.
zhemao··on How Canada became an education superpower
Very true. I don't think the Republicans are solely to blame though. I live in the SF Bay Area, definitely a very blue part of the country. Despite pretty steep taxes, our public transportation and public schools aren't much to look at. Better than other parts of the country, probably, but it ain't Canada. Even when there's a political will, there doesn't seem to be much know-how in how to actually provision public infrastructure and services in an efficient way.
zhemao··on How Canada became an education superpower
And if you came to the US and saw our public schools here, you'd probably die of laughter.
zhemao··on How Canada became an education superpower
Oh look, yet another article about a country that's doing education better than us here in the US. And the funny thing is that they all seem to do things in different ways.

You know what I think the problem is? Americans on the whole just don't care about public education. Either in terms of quality or equity.

zhemao··on Life Inside Hong Kong’s ‘Coffin Cubicles’
LMAO. I didn't even get a chance to read illegal_in_ca's reply before it got flagged. What did they even say to generate this much controversy? (Probably something really stupid).

And even aside from the obvious moral problems of extreme wealth inequality, it's not even economically efficient. You can't have a strong and growing market economy without a middle class. Hong Kong could get away with it for some time because their economy is based on international trade and finance, but that only takes you so far. Eventually you need to develop a domestic consumer base. Their current political crisis is caused by this inequality catching up to them, though the HK business and political elite conveniently pass the blame to Beijing.

zhemao··on Life Inside Hong Kong’s ‘Coffin Cubicles’
It also has one of the highest levels of income inequality, which is what this article highlights.
zhemao··on Life Inside Hong Kong’s ‘Coffin Cubicles’
The picture of the combo toilet-kitchen made me viscerally upset. That must be so unsanitary.
zhemao··on VPN crackdown ‘unthinkable’ trial by firewall for China’s research world
> However the various administrations since then have spent significant resources and time going in different (and sometime opposite) directions, and not always in a blunder-safe way.

Yeah, because there are different factions within the party that sometimes have conflicting goals or ideas. It's not as unified as outsiders think it is. I agree that they aren't always scary competent. The whole Bo Xilai scandal was a huge black eye that they didn't see coming, for instance.

> The example I have in mind is the declaration last month by the foreign affairs ministry that the Hong Kong "Joint Declaration" is not binding any more for China.

What? I didn't hear about this at all. That does seem pretty crazy. Do you have a link to a news article?

> After all there are other countries (Japan, Russia, France...) where English has a low penetration rate

Don't know about Russia or France, but Japan still teaches English in schools. Japan and China probably have a similar "penetration rate" for English. They do lots of business done with English speaking countries but the average man on the street is by no means fluent. I suspect the same is true of France. If domestic consumer demand increases, China might be able to get away with it, but the export economy is so big, I can't see them making that choice.

zhemao··on VPN crackdown ‘unthinkable’ trial by firewall for China’s research world
The current norms of CCP leadership were established in the aftermath of the Cultural Revolution for the express purpose of avoiding such a catastrophe in the future. Since 1989, the guiding philosophy of China's central leadership has been economic growth in exchange for limits on political freedom. The CCP is currently shooting itself in the foot in numerous ways (the VPN ban being one of them), but crippling the country's economic competitiveness by limiting English language instruction is not something they would ever consider.
zhemao··on VPN crackdown ‘unthinkable’ trial by firewall for China’s research world
I really wonder how contemporary Chinese students square the information from their Marxism class with what Chinese society is like today. Does the Marxism class teach real Marxism or "Marxism with Chinese characteristics"? Granted, it's doubtful most students pay much attention to it anyway, since they just need to memorize the info and regurgitate it on the exam.
zhemao··on VPN crackdown ‘unthinkable’ trial by firewall for China’s research world
Yes, this is definitely true. Porn sites are also blocked for instance. Political censorship is the primary purpose of the firewall, but since the tool already exists, they go ahead and block things that don't fit into their conception of a "harmonious society".
zhemao··on VPN crackdown ‘unthinkable’ trial by firewall for China’s research world
It's not just the technical services those platforms provide, but also the content hosted on them and the other users who use them. The article mentions Dropbox and Google Drive. Even if a Chinese file-sharing service was created as a replacement, good luck convincing foreign collaborators to use it. Also blocked are YouTube and Twitter, which are great platforms for promoting your work to a global audience. I just don't see the Chinese government handicapping their researchers this way just for some extra control.

What's more likely is they'll work out a deal with trusted universities and corporations to give their employees access to an official VPN through which they can get unrestricted internet access. But all traffic through this VPN will be closely monitored.

zhemao··on VPN crackdown ‘unthinkable’ trial by firewall for China’s research world
Uh. Are you thinking of Japan? The Qing dynasty was brought down by more than just a few gunships.

Though the larger point about isolationism is still valid.

zhemao··on Older fathers have 'geekier sons'
Genetic mutations. As you get older, you accumulate more genetic damage, which can be passed on to children. It's fairly well-studied that children of older parents are more susceptible to genetic disorders.
zhemao··on Program FPGAs with Go
Yes, I'm talking about FIRRTL, which is used in the latest version of Chisel (Chisel 3).

There aren't official releases of this version yet, but you can get snapshots (if you don't mind some API breakage now and then). It works fairly well now and we use it in all our RTL designs.

Page 1 of 27Next →