What came after the 486? • Hacker News Board

Re: What came after the 486?

#151

Post by twoodfin » Fri, Mar 27, 2026, 3:34 PM UTC

AdamN wrote: post #143

twoodfin wrote: post #108

Earlier quoted context omitted.

In the end, Intel did cannibalize themselves. It wasn’t too long after the Itanium launch that Intel was publicly presenting a roadmap that had Xeons as the appealing mass-market server product.

Yeah they actually survived quite well. Who knows how much they put into Itanium but in the end they did pull the plug and Xeons dominated the market for years. They even had a chance with mobile chips using ATOM but ARM was too compelling and I think Apple was sick of the Intel dependency so when there was an opportunity in the mobile space to not be so deeply tied to Intel they took it.

I think the difference was that replacing Itaniums with Xeons on the roadmap didn't seriously hurt margins (probably helped!)

The problem with mobile was that it fundamentally required low-margin products, and Intel never (or way too late) realized that was a kind of business they should want to be in.

Re: What came after the 486?

#152

Post by twoodfin » Fri, Mar 27, 2026, 3:38 PM UTC

p_l wrote: post #132

phire wrote: post #61

Earlier quoted context omitted.

> It’s as if they actually bought into the RISC FUD from the 1990’s that x86 was unscalable, exactly when it was taking its biggest leaps. That's exactly what was happening. Though it helps to realise that this argument was taking place inside Intel around 1997. The Pentium II is only just hitting the market, it wasn't exactly obvious that x86 was right in the middle making its biggest leaps. RISC was absolutely domi…

Honestly what broke Itanium the most was the extreme market segmentation that made Itanium very expensive with no path to mass use. Resulting in claim like "it's pretty good DSP, but hilariously overpriced".

Exactly! But this was not just obvious in retrospect, it was what Intel was saying to the market (& OEMs) at the time!

The only way I can rationalize it is that Intel just "missed" that servers hooked up to networks running integer-heavy, branchy workloads were going to become a big deal. OK, few predicted the explosive growth of the WWW, but look around at the growth of workgroup computing in the early 1990's and this should have been obvious?

Re: What came after the 486?

#153

Post by mfro » Fri, Mar 27, 2026, 4:01 PM UTC

zozbot234 wrote: post #63

homebrewer wrote: post #59

Earlier quoted context omitted.

Those sellers never disappeared; although I'm from not from Paraguay, the situation is familiar. These days they're selling desktops built on 10+ year old Xeons which you can buy for dirt cheap on AliExpress, installed on frankenstein motherboards from noname Chinese manufacturers which are desktop-oriented, but take server processors. The graphics card is something old like RX480, and comes from being run into the g…

The notion that GPU chips can be "run into the ground" by years of crypto mining or AI workloads has been debunked pretty thoroughly by now. The hardware is quite resilient, it doesn't really fail at a higher rate.

I think the problem is the distinction here between chips and boards. The entire GPU assembly can absolutely be worn down from continuous use, thermal pads, paste, VRMs, fans do degrade. The chip itself may be fine but it's very rare to find anyone willing to transplant a GPU from one board to another.

Re: What came after the 486?

#154

Post by p_l » Fri, Mar 27, 2026, 4:08 PM UTC

AdamN wrote: post #142

hulitu wrote: post #139

Earlier quoted context omitted.

> and thought that they needed a totally pro architecture (which Itanium was). Was it though ? They made a new CPU from scratch, promissing to replace Alpha, PA-RISC and MIPS, but the first release was a flop. The only "win" of Itanium that I see, is that it eliminated some competitors in low and medium end server market: MIPS and PA-RISC, with SPARC being on life support.

I never used them but my understanding is that the performance was solid - but in a market with incumbents you don't just need to be as good as them you need to be significantly better or significantly cheaper. My sense was that it met expectations but that it wasn't enough for people to switch over.

Merced (first generation Itanium) had hilariously bad performance, and its built in "x86 support" was even slower.

HP-designed later cores were much faster and omitted x86 hardware support replacing it with software emulation if needed, but ultimately IA-64 rarely ever ran with good performance as far as I know.

Pretty sure it was Itanium that finally turned "Sufficiently Smart Compiler" into curse phrase as it is understood today, and definitely popularized it.

Re: What came after the 486?

#155

Post by weirdmantis69 » Fri, Mar 27, 2026, 4:23 PM UTC

specproc wrote: post #8

I remember writing a cyberpunk story as a kid, in which everyone was rocking badass 786s.

Sadly still in the far future

Re: What came after the 486?

#156

Post by phire » Sat, Mar 28, 2026, 11:20 AM UTC

twoodfin wrote: post #152

p_l wrote: post #132

Earlier quoted context omitted.

Honestly what broke Itanium the most was the extreme market segmentation that made Itanium very expensive with no path to mass use. Resulting in claim like "it's pretty good DSP, but hilariously overpriced".

Exactly! But this was not just obvious in retrospect, it was what Intel was saying to the market (& OEMs) at the time! The only way I can rationalize it is that Intel just "missed" that servers hooked up to networks running integer-heavy, branchy workloads were going to become a big deal. OK, few predicted the explosive growth of the WWW, but look around at the growth of workgroup computing in the early 1990's and th…

I'm not sure thats a fair description of server workloads. I'm also not sure it's fair to say Itanium was bad at integer-heavy, branchy workloads (at least not compared to Netburst)

The issue is more that server workloads are very memory bound, and it turns out the large OoO windows do an exceptional job of hiding memory latency. I'm sure the teams actually building OoO processors knew this, but maybe it wasn't obvious outside them.

Besides, Itanium was also designed to hide memory latency with its very flexible memory prefetch systems.

The main difference between the two approaches is static scheduling vs dynamic scheduling.

Itanium was the ultimate expression of the static scheduling approach. It required that mythical "smart enough compiler" to statically insert the correct prefetch instructions at the most optimal places. They had to strike a balance simultaneously wasting resources issuing unneeded prefetches and unable to issue enough prefetches because they were hidden behind branches.

While the OoO x86 cores had extra runtime scheduling overhead, but could dynamically issue the loads when they were needed. An OoO core can see branches behind multiple speculative branches (dozens of speculative branches on modern cores). And a lot of people miss the fact than an OoO core can actually take the branch miss-predict penalty (multiple times) that are blocked behind a slow memory instruction that's going all the way to main memory. Sometimes the branch mispredict cycles are entirely hidden.

In the 90s, static scheduling vs dynamic scheduling was very much an open question. It was not obvious just how much it would fall flat on its face (at least for high end CPUs).

Re: What came after the 486?

#157

Post by dice » Sat, Mar 28, 2026, 4:36 PM UTC

moefh wrote: post #119

dice wrote: post #73

Earlier quoted context omitted.

0xf00fc7c8

Shouldn't that be 0xc8c70ff0, since we're talking about a little-endian CPU? (according to this[1] the bytes in memory are F0 0F C7 C8). On the other hand, I probably wouldn't have recognized the F00F bug mention if you had actually written 0xc8c70ff0. [1] https://en.wikipedia.org/wiki/Pentium_F00F_bug

It was a popular meme in computer security focused groups for a while after it was discovered since it was an unprivileged DoS. I only remember seeing it talked about with the f00f representation: some people even called it "getting f00f'd" if you managed to trick someone into executing the instructions.

Re: What came after the 486?

#158

Post by p_l » Sun, Mar 29, 2026, 6:26 PM UTC

twoodfin wrote: post #33

p_l wrote: post #27

Earlier quoted context omitted.

Around the time of K8 being released, I remember reading official intel roadmaps announced to normal people, and they essentially planned that for at least few more years if not more they will segment into increasingly consumer-only 32bit and IA-64 on the higher end

Itanium was bonkers in lots of ways—very cool in others. But this market segmentation idea just seems absolutely insane to me in a way I’ve never had anyone satisfactorily explain. It requires Intel to voluntarily destroy the commodity economics that put their CPUs on a rocket ship to domination. It’s as if they actually bought into the RISC FUD from the 1990’s that x86 was unscalable, exactly when it was taking its…

Just remembered that part of the story:

Part of the effort to ditch x86 was to destroy competition that existed due to second sourcing agreements. After already trying and losing in court the case to prevent AMD and others from making compatible chips, Intel hoped to push IA-64 for the lucrative high performance markets it dominated in PCs, and prevent rise of compatible designs from other vendors.