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Moore’s Law is dead – Long live the chiplet

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Re: Moore’s Law is dead – Long live the chiplet

#51

Post by zozbot234 »

MrFoof wrote: post #46
zozbot234 wrote: post #43

Earlier quoted context omitted.

If you truly wanted to maximize performance per watt , you'd pick a very different design more reminiscent of GPU's. But then single-thread and low-multi-thread performance would really suck. So it will always be a carefully tuned tradeoff.

Nope. Not even. Again, as the grandparent post stated, everything is being sold with the default configuration being redlined. You absolutely can reign it back in to sanity, and get better performance per watt over the previous gen, and still be noticeably faster over the previous gen. -- ----- With AMD, apparently we're going to see BIOS updates from board manufacturers to make doing that simple. Set it to a lower p…

You don't even really need to rein it back, modern processors will throttle back automatically depending on how effective the cooling is. Anyway, the issue with manual undervolting is that it may adversely impact reliability if you ended up with a slightly substandard chip, that will still work fine at stock settings. That's why it can't just be a default.

Re: Moore’s Law is dead – Long live the chiplet

#52

Post by [deleted] »

somat wrote: post #49

I am not convinced moore's law no longer holds true, consider that there is a third dimension that no one has yet figured out. I am no silicon engineer but I suspect a chip that fully takes advantage of the third dimension would be something like a sponge full of built in channels for the working fluid to remove heat. First however I suspect you will see chiplets arranged vertically like heatsink fins and the whole c…

[deleted]

Re: Moore’s Law is dead – Long live the chiplet

#53

Post by BirAdam »

Unless I’m missing something, the article did mention Moore’s law proper with transistor density doubling every 18 months, but then meandered to talk about other things. M1 has 16 billion transistors thanks to TSMC. Each new node has delivered on Moore’s law with AMD and Apple. I don’t doubt that Moore’s law will stop. I can even say that it Moore’s law may have failed from time to time, but the spirit of the law lives.

Moving to chiplets doesn’t change transistor density. This is a packaging feature and not a fabrication feature. This is done for manufacturing cost reduction and yield improvements.

Re: Moore’s Law is dead – Long live the chiplet

#54

Post by alexvoda »

tapanjk wrote: post #44

> Obviously, given these data, volume is VERY important in business models that operate with high fixed and low variable costs. Off-topic but I wonder how much cheaper mobile phones would be if the manufacturers did not have to come up with a hardware design update every year or so? What if mobile phones were built to last longer, which would reduce the cost per phone due to high volume? Of course, I am not suggestin…

At this point the most direct and highest impact way of making phones last longer is forcing Qualcomm to support their chipsets for more than 2 years.

Re: Moore’s Law is dead – Long live the chiplet

#55

Post by MrFoof »

zozbot234 wrote: post #51
MrFoof wrote: post #46

Earlier quoted context omitted.

Nope. Not even. Again, as the grandparent post stated, everything is being sold with the default configuration being redlined. You absolutely can reign it back in to sanity, and get better performance per watt over the previous gen, and still be noticeably faster over the previous gen. -- ----- With AMD, apparently we're going to see BIOS updates from board manufacturers to make doing that simple. Set it to a lower p…

You don't even really need to rein it back, modern processors will throttle back automatically depending on how effective the cooling is. Anyway, the issue with manual undervolting is that it may adversely impact reliability if you ended up with a slightly substandard chip, that will still work fine at stock settings. That's why it can't just be a default.

>You don't even really need to rein it back, modern processors will throttle back automatically depending on how effective the cooling is

This isn't about thermals. This is about power consumption.

I'm not suggesting reigning in a CPU's power limits because it's "too hot".

I'm suggesting getting 95% of the performance for 59% of the power consumption. Because it's not worth spending 72% more on electricity for 5% increased performance. Again, even the manufacturers themselves know this and are admitting it. Look at this slide from Intel: https://cdn.arstechnica.net/wp-content/uploads/2022/09/13th-... Purported identical performance of previous gen at 25% of the power consumption. They KNOW the default configuration setting (which you can change in a few keystrokes) is total garbage in terms of power efficiency.

-----

I guarantee you server CPUs aren't going to be configured to be this idiotic out of the box. Because in the datacenter, perf/W matters and drives purchasing decisions.

Re: Moore’s Law is dead – Long live the chiplet

#56

Post by londons_explore »

aargh_aargh wrote: post #19

For dummies like me who didn't know what a chiplet is: https://en.wikipedia.org/wiki/Chiplet This seems to be about the third reason listed: > Known good die (KGD): chiplets can be tested before assembly, improving the yield of the final device Problem: > In general, a killer defect is defined as a defect that is 20% the size of the fabrication node. For > example, a defect that is less than 9nm may be acceptable for…

Is silicon manufacturing done entirely in a vacuum yet?

Because a vacuum pretty eliminates dust - with no air, dust just falls towards either the ground (if it is uncharged), or towards a positive or negatively charged surface (if the dust particle itself is charged).

Re: Moore’s Law is dead – Long live the chiplet

#57

Post by nordsieck »

aargh_aargh wrote: post #19

For dummies like me who didn't know what a chiplet is: https://en.wikipedia.org/wiki/Chiplet This seems to be about the third reason listed: > Known good die (KGD): chiplets can be tested before assembly, improving the yield of the final device Problem: > In general, a killer defect is defined as a defect that is 20% the size of the fabrication node. For > example, a defect that is less than 9nm may be acceptable for…

The issue that you seem to be skirting around but not mentioning is, the chance a chip has a defect increases with die area since defects are randomly distributed across the surface of the wafer. Chiplets are a way for manufacturers to practically increase die area while keeping yields high.

Re: Moore’s Law is dead – Long live the chiplet

#58

Post by rcxdude »

londons_explore wrote: post #56
aargh_aargh wrote: post #19

For dummies like me who didn't know what a chiplet is: https://en.wikipedia.org/wiki/Chiplet This seems to be about the third reason listed: > Known good die (KGD): chiplets can be tested before assembly, improving the yield of the final device Problem: > In general, a killer defect is defined as a defect that is 20% the size of the fabrication node. For > example, a defect that is less than 9nm may be acceptable for…

Is silicon manufacturing done entirely in a vacuum yet? Because a vacuum pretty eliminates dust - with no air, dust just falls towards either the ground (if it is uncharged), or towards a positive or negatively charged surface (if the dust particle itself is charged).

No (at least not entirely: some steps are done in a vacuum or very low pressure), in part because it's harder to get a vacuum than clean enough air. Also it would cause a lot of other problems as well as not solving the whole problem: a lot of processing steps involve applying chemicals to the surface of the wafer, washing off those chemicals, or otherwise handling liquids which would boil in a vacuum. Those chemicals (including just plain water), also carry the same risk of introducing 'killer particles', so they are also a big part of the process control needed in a fab (the levels of contaminants in water that is required on modern process nodes is actually lower than can be detected practically with current technology: the last levels of water purification are effectively done blind, with yield as the only feedback mechanism).

Re: Moore’s Law is dead – Long live the chiplet

#59

Post by wongarsu »

BirAdam wrote: post #53

Unless I’m missing something, the article did mention Moore’s law proper with transistor density doubling every 18 months, but then meandered to talk about other things. M1 has 16 billion transistors thanks to TSMC. Each new node has delivered on Moore’s law with AMD and Apple. I don’t doubt that Moore’s law will stop. I can even say that it Moore’s law may have failed from time to time, but the spirit of the law liv…

One interesting point is that even if Moore's law stops or slows down, chiplets allow us to increase transistor count independently of transistor density. Thus keeping alive the spirit of the law (processors get more and more transistors).

Re: Moore’s Law is dead – Long live the chiplet

#60

Post by urthor »

theaeolist wrote: post #20

Even if the Moore's law is not dead, single-thread performance and clock frequency have plateaued 10 years ago. This is the key factor. Because of heating even if you squeeze more transistors onto a chip you need to reduce the clock, so even if you may get higher computational throughput the latency will go down. And this is another argument for chiplets or any other alternative computational architectures.

> single-thread performance and clock frequency have plateaued 10 years ago

https://www.cpubenchmark.net/singleThread.html

It's amazing how often this is parroted. Anyone with a passing familiarity with the numbers knows this is actually not true at all.

Better caching, branch prediction, plus vast amounts of SRAM. There's been a slow & steady increase in the vast variety of single threaded workloads grouped together by "instructions per clock."

Both at the peak of the voltage frequency curve for workstations & overclocking, the apex of the optimization curve for data centre, and especially at the bare minimum for mobile devices with idle workloads.

Yes, it's a small fraction of the old days. It's still double in 10 years.

And as anyone who's migrated from an Intel Mac to Apple Silicon knows, "merely doubling" is a LOT.

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