John Carmack's arguments against building a custom XR OS at Meta • Hacker News Board

Re: John Carmack's arguments against building a custom XR OS at Meta

#581

Post by WalterBright » Sat, Aug 30, 2025, 6:05 PM UTC

cornstalks wrote: post #567

WalterBright wrote: post #456

Earlier quoted context omitted.

I may be the only person who ever understood every detail of C++, starting with the preprocessor. I can make that claim because I'm the only person who ever implemented all of it. (You cannot really know a language until you've implemented it.) I gave up on that in the 2000's. Modern C++ is simply terrifying in its complexity. (I'm not including the C++ Standard Library, as I didn't implement it.)

You've done some great work but I have to call BS with this claim: > I'm the only person who ever implemented all of it. Sean Baxter is an easy counter example.

I don't know much of anything about him. Did he implement the preprocessor? the optimizer? the code generator?

(For some context, back in the 80's, code generators needed enhancements to implement C++. You couldn't just use an existing one. Bjarne had to do some ugly workarounds because of this.)

Re: John Carmack's arguments against building a custom XR OS at Meta

#582

Post by theideaofcoffee » Sat, Aug 30, 2025, 6:08 PM UTC

dist1ll wrote: post #200

jnwatson wrote: post #23

I've written a lot of low level software, BSPs, and most of an OS, and the main reason to not write your own OS these days is silicon vendors. Back in the day, they would provide you a spec detailed enough that you could feasibly write your own drivers. These days, you get a medium-level description and a Linux driver of questionable quality. Part of this is just laziness, but mostly this is a function of complexity.…

Intel still does it. As far as I can see they're the only player in town that provide open, detailed documentation for their high-speed NICs [0]. You can actually write a driver for their 100Gb cards from scratch using their datasheet. Most other vendors would either (1) ignore you, (2) make you sign an NDA or (3) refer you to their poorly documented Linux/BSD driver. Not sure what the situation is for other hardware…

That's interesting that it's that short. I remember a long while ago I had aspirations of implementing a custom board for Prestonia-/Gallatin-era Xeons and the datasheets and specs for those was around 3000 pages, iirc. Supporting infra was about that long as well. So I'm surprised to see a modern ethernet controller fit into the same space. I appreciated all of the docs because it was so open, I felt like I could actually achieve that project, but other things took priority.

Re: John Carmack's arguments against building a custom XR OS at Meta

#583

Post by mrandish » Sat, Aug 30, 2025, 6:22 PM UTC

throwaway2037 wrote: post #345

dist1ll wrote: post #200

Earlier quoted context omitted.

Intel still does it. As far as I can see they're the only player in town that provide open, detailed documentation for their high-speed NICs [0]. You can actually write a driver for their 100Gb cards from scratch using their datasheet. Most other vendors would either (1) ignore you, (2) make you sign an NDA or (3) refer you to their poorly documented Linux/BSD driver. Not sure what the situation is for other hardware…

Wow... that PDF is 2,750 pages! There must be an army of technical writers behind it. That is an incredible technical achievement. Real question: Why do you think Intel does this? Does it guarantee a very strong foothold into data center NICs? I am sure competitors would argue two different angles: (1) this PDF shares too much info; some should be hidden behind an NDA, (2) it's too hard to write (and maintain) this P…

> Real question: Why do you think Intel does this?

I'm not sure large traditional silicon vendors like Intel, TI, et al re-evaluate the documentation requirements (and costs) on a chip by chip basis. It's probably done by chip class and for companies who've been selling chips by the millions over many decades to industries as diverse as defense, aerospace, automotive, etc there are classes of chips where robust, complete documentation is not only expected but often a required part of the RFP, compliance or conformance processes.

While this level of effort probably isn't needed for every chip in that class, it could be hard to reliably predict when a general purpose chip is still in the design phase which customers may be interested in it during its life (which for some of these chips might be decades). Many chips which conform to MIL-SPEC or other similar standards which can require extensive documentation are simply enhanced versions of standard chips, so the docs exist anyway. Finally, there's the organizational capabilities and culture aspect. Once the org needs to maintain the systemic ability to generate serious documentation at scale, you end up with a lot of managers and staff who think this way.

Re: John Carmack's arguments against building a custom XR OS at Meta

#584

Post by daseiner1 » Sat, Aug 30, 2025, 6:25 PM UTC

dagmx wrote: post #298

kid64 wrote: post #292

Earlier quoted context omitted.

Are you arguing that everyone's power is equal? What an asinine position.

It must either be a belief that everyone is equal, and that they would be comfortable telling Carmack that he’s wrong. Or it’s an appeal to authority in that if a person of authority says it then they must be right so there’s no reason to push back in the first place.

i would absolutely feel comfortable challenging him in a well-intentioned and non-disruptive manner. it's entirely possible i'd get shitcanned afterwards and if so, that's fine, it wouldn't've worked out anyways for me if that's the environment. i've personally never been afraid to challenge people above me on the org chart who have the ability to fire me with a snap of their fingers (again, in appropriate, non-grossly confrontational ways). it's generally worked out quite well for me and tends to gain me respect in the eyes of my superiors. successful people tend not to have great respect for sycophants.

the good news is that in this hypothetical i'd be skilled and talented enough to be working with john fucking carmack so i wouldn't exactly be concerned about my ability to find a new gig in about 3 days. that's my point. now if there were evidence he'd be liable to blackball me in some way (no evidence of that to my knowledge), then the power disparity argument has more legs in my opinion.

Re: John Carmack's arguments against building a custom XR OS at Meta

#585

Post by LPisGood » Sat, Aug 30, 2025, 6:58 PM UTC

izacus wrote: post #401

LPisGood wrote: post #355

Earlier quoted context omitted.

Unfortunately people have ideas, projects, and solutions that they care deeply about. Like it or not, some tact when dealing with these things goes a long way.

I mostly notice that those people aren't emotionally grown up enough to actually produce good results. When your emotions over your work become more important than the quality of the work you're outputting, you become a problem for people who use your work.

Well unfortunately even relatively high quality organizations are filled with people like that.

Re: John Carmack's arguments against building a custom XR OS at Meta

#586

Post by Conscat » Sat, Aug 30, 2025, 7:11 PM UTC

WalterBright wrote: post #456

throwaway2037 wrote: post #345

Earlier quoted context omitted.

Wow... that PDF is 2,750 pages! There must be an army of technical writers behind it. That is an incredible technical achievement. Real question: Why do you think Intel does this? Does it guarantee a very strong foothold into data center NICs? I am sure competitors would argue two different angles: (1) this PDF shares too much info; some should be hidden behind an NDA, (2) it's too hard to write (and maintain) this P…

I may be the only person who ever understood every detail of C++, starting with the preprocessor. I can make that claim because I'm the only person who ever implemented all of it. (You cannot really know a language until you've implemented it.) I gave up on that in the 2000's. Modern C++ is simply terrifying in its complexity. (I'm not including the C++ Standard Library, as I didn't implement it.)

Sean Baxter single-handedly implemented all of up to C++23, and some C++26, including a huge number of GNU extensions and possibly an even larger number of his own features.

Re: John Carmack's arguments against building a custom XR OS at Meta

#587

Post by izacus » Sat, Aug 30, 2025, 7:12 PM UTC

LPisGood wrote: post #585

izacus wrote: post #401

Earlier quoted context omitted.

I mostly notice that those people aren't emotionally grown up enough to actually produce good results. When your emotions over your work become more important than the quality of the work you're outputting, you become a problem for people who use your work.

Well unfortunately even relatively high quality organizations are filled with people like that.

sigh I know, I know. :/

Re: John Carmack's arguments against building a custom XR OS at Meta

#588

Post by flkenosad » Sat, Aug 30, 2025, 7:17 PM UTC

Hydraulix989 wrote: post #578

mrandish wrote: post #561

> I wish I could drop (so many of) my old internal posts publicly, since I don’t really have the incentive to relitigate the arguments today – they were carefully considered and prescient. They also got me reported to HR by the manager of the XROS effort for supposedly making his team members feel bad Carmack being Carmack, I'm sure the HR report came to nothing but it's just another reminder of the annoyances I don'…

You don't report someone like Carmack to HR, it will only backfire and make your ignorance even more visible. Also, I am not surprised he was reported -- typical underhanded political hustling commonplace at Meta.

Report whoever you want to HR people. Don't listen to this guy ^

Re: John Carmack's arguments against building a custom XR OS at Meta

#589

Post by throwboy2047 » Sat, Aug 30, 2025, 7:23 PM UTC

mrandish wrote: post #561

> I wish I could drop (so many of) my old internal posts publicly, since I don’t really have the incentive to relitigate the arguments today – they were carefully considered and prescient. They also got me reported to HR by the manager of the XROS effort for supposedly making his team members feel bad Carmack being Carmack, I'm sure the HR report came to nothing but it's just another reminder of the annoyances I don'…

My first month at Amazon someone reported me for laughing at them…I didn’t even know they existed, on the other end of the open floor. I was laughing at something completely unrelated.

That made me really think about how fragile and toxic people can be.

Another Amazonian almost got fired for reacting with a monkey covering eyes emoji to a post shared by a black person (no malintent, of course, just an innocent “mistake” most normal people wouldn’t even think twice about).

Re: John Carmack's arguments against building a custom XR OS at Meta

#590

Post by kelipso » Sat, Aug 30, 2025, 7:26 PM UTC

bckr wrote: post #569

kelipso wrote: post #509

Earlier quoted context omitted.

Ugh. Can we as an industry stop blowing people up like this? It’s a clear sign that the community is filled with people with very little experience. I remember this guy wanted $20 million to build AGI a year ago (did he get that money?), and people here thought he would go into isolation for a few weeks and come out with AGI because he made some games like that. It’s just embarrassing as a community.

> $20 million That’s a pittance for such a project. I wish we could see what he’d have come up with.

He is just a guy who can write game code well and has good PR skills online. I wouldn’t give him a cent if he promised anything in the AI field, no matter how much a bunch of online people gas him up.