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I'm a bit baffled about chiplets stealing all the headlines in the tech news sites ever since AMD started using them in Ryzen, with people preaching this to be

I'm a bit baffled about chiplets stealing all the headlines in the tech news sites ever since AMD started using them in Ryzen, with people preaching this to be the AMD & TSMC killer innovation when actually we've seen them in consumer chips for over 15 years now, from Intel at least The Intel Pentium D in 2005 was basically two Pentium CPU dies glued close to each other on the same package to create the first ever consumer dual core CPU.[1] The Intel Core 2 Quad from 2007 was basically two separate Core 2 Due dies glued close to each other on the same package to create the first ever quad core consumer CPU. I had a 2011 laptop with an Intel P4600 Celeron chip that had the discrete CPU die and GPU dies separated, both on the same package.[2] I remember this clearly since I first took it apart to clean the fan and apply new thermal paste and I was surprised to see two different dies on the package. And those are the chiplet based chips I know off the top of my head, there probably are even more earlier designs I don't know about, so is there some hidden chiplet agenda that sprung up recently which I'm missing or what's going on? [1] https://www.hardwarezone.com.sg/m/feature-intels-pentium-xe-965-and-955-processors/presler-core https://www.hardwarezone.com.sg/m/feature-intels-pentium-xe-... [2] https://www.x86-guide.net/Xhoba/en/collection/Intel-Celeron-P4600-cpu-no12016.html https://www.x86-guide.net/Xhoba/en/collection/Intel-Celeron-...

natpalmer1776 4y ago
Marketing & viral awareness go brrrrrr Edit since this was pretty low effort and likely violates the community guidelines I'll add this: I would guess the reason for seeing more content related to chiplets and their implications is due to a combination of seeing a big player adopt them for their main product line(s) and the resulting PR / marketing buzz that occurs as a result of that having 'trickle down' effects on the general industry discourse as a whole.
- tdba 4y ago
  Also the USG is making a big push to reshore chip manufacturing, especially in more future-facing areas such as chiplets.
  - natpalmer1776 4y ago
    Took me longer than I care to admit to realize that USG stood for United States Government. Regarding the statement, I also would point out that there is an almost global push towards promoting domestic chip manufacturing and reducing the reliance on globalization of critical infrastructure, not just in the United States. In my geopolitical armchair expert opinion, I would guess this is in part caused by the conflict in Ukraine as well as rising tensions between the various 'global powers' further compounding the general loss of confidence that followed COVID-19.
    - tdba 4y ago
      This push began before Covid and well before the war in Ukraine went hot - but those two factors certainly increased the urgency. At root the push in the US began due to the rise of China as a military competitor in the early 2010s, and the consequent realization that TSMC might be blockaded, captured or destroyed.
cma 4y ago
Pentium D was a multi chip module, and so are AMD's chiplets, but Pentium D didn't use chiplets: > ICs that can perform most, if not all of the functions of a component of a computer, such as the CPU. Examples of this include implementations of IBM's POWER5 and Intel's Core 2 Quad. Multiple copies of the same IC are used to build the final product. In the case of POWER5, multiple POWER5 processors and their associated off-die L3 cache are used to build the final package. With the Core 2 Quad, effectively two Core 2 Duo dies were packaged together. > ICs that perform only some of the functions, or "Intellectual Property Blocks" ("IP Blocks"), of a component in a computer. These are known as chiplets.[3][4] An example of this are the processing ICs and I/O IC of AMD's Zen 2-based processors. https://www.wikipedia.org/wiki/Multi-chip_module https://www.wikipedia.org/wiki/Multi-chip_module It seems chiplets are a different subset but it is very similar. Also, AMD used different process nodes for different parts, where that wouldn't make sense in just a dual cpu package, and certain circuitry is now starting to scale different as process nodes shrink, so they may want a different older process node for cache than for logic, etc. which could emphasize the different functions aspect and explain why it is in the news more. 3d v-cache uses an older node for that reason, though needs more thorough connectivity than chiplet tech so uses interposers I think. You might also want to buy third-party IP that is only available created with design rules from a different foundry. Chiplets let you integrate it, where an approach like SoCs wouldn't. Shot noise is a bigger problem in EUV, so you can potentially get better yields by splitting functional components into different chiplets rather than the alternative of fusing off parts of a chip and selling it as a lower tier. Those are the reasons I see as to why they are getting lots of press and attention even though the packaging technology may be old. Initial reasons for mixing nodes may have been more business related than technical: AMD had to buy a certain amount of output from global foundries after spinning it off.
- wtallis 4y ago
  I think another important distinction between today's chiplet CPUs and the Pentium D/Core 2 Quad is that those early parts were still using a traditional shared front side bus connecting CPU cores to the memory controller/northbridge residing on the motherboard. So those MCMs were functionally equivalent to a dual-socket system even from a performance perspective, but harder to cool. AMD's chiplet-based CPUs gain some real benefits from using faster or lower-power short-range links that would not work between separate CPU sockets, and more advanced packaging using interposers or bridges further reduce the power and performance costs of communication between chiplets. These benefits mattered even for AMD's early chiplet-based CPUs that were homogeneous rather than using a mix of specialized dies.
dragontamer 4y ago
Interposers. The start of "modern" chiplets was AMD's R9 Nano GPU, which I believe was the first to use HBM / stacked memory. Each stack has 1024 microbumps, and the GPU has 4 stacks, meaning 4096 bumps/pins connect the GPU with its RAM. EDIT: The pitch between these microbumps is 40 microns / 0.040 milimeters. This technology is "advanced packaging", the ability to provide thousands, or even tens-of-thousands, of bumps / effective pins to serve the signals going across our computers. ------------- Yeah, chiplets or even socket-to-socket communications, have existed for decades. But today we can take advantage of thousands, tens-of-thousands, or even hundreds-of-thousands of external "pins" that connect these components together. Here's a rundown on Intel's technology: https://www.anandtech.com/show/16823/intel-accelerated-offensive-process-roadmap-updates-to-10nm-7nm-4nm-3nm-20a-18a-packaging-foundry-emib-foveros/4 https://www.anandtech.com/show/16823/intel-accelerated-offen... > Intel is also stating today that it will be using its second generation Foveros technology on the platform, implementing a bump pitch of 36 micron, effectively doubling the connection density over the first generation. 36 microns, or 36 um (micrometers) pitch density on Intel's advanced packaging technology. That's a lot of pins per mm^2! Now I don't know how these guys are lining up 0.036 milimeter bumps and reliably making connections. I kind of imagine a very tiny soldering iron, but I'm probably wrong. ------- In practice, AMD has led the way. Not only with "chiplets", but also off-die L3 cache (aka: x3d cache), adding 64MB of external SRAM to their chips through advanced packaging. So these thousands-of-microbumps are fast, reliable, and low-power enough to provide full-speed caches (something not quite possible with those earlier Pentiums you were talking about).
- paulmd 4y ago
  > Interposers. Interposers are just one way of packaging MCM designs. AMD's RX 7900 series doesn't use a silicon interposer, it's still an (early) MCM design (although of course it's only pulling out memory controllers and cache, not multi-GCD). And technically since it's already a fiberglass package, there's no reason you can't stick things right onto a PCB instead, it's just a matter of convenience for partners placing/routing one thing instead of 7 things. https://www.techpowerup.com/301071/amd-explains-the-economics-behind-chiplets-for-gpus https://www.techpowerup.com/301071/amd-explains-the-economic... Infinity Fanout integration is a different type of MCM integration with some of its own upsides (cost) and downsides (higher power, less bumpout). There's also bridges, and actual 3D stacks of multiple compute dies (or 2.5D with memory/etc) that don't use interposers at all. https://semiengineering.com/using-silicon-bridges-in-packages/ https://semiengineering.com/using-silicon-bridges-in-package... All of these are technically MCM - MCM is any sort of multi-chip package. MCM also really does include things like Core2Quad, Pentium-D, Crystalwell, Xenos, and various IBM modules in the 70s and 80s. The idea has been kicking around for a long time and "multi-chip module" refers to all of them collectively, not just interposer-based CPUs. https://en.wikipedia.org/wiki/Multi-chip_module https://en.wikipedia.org/wiki/Multi-chip_module And while yes, stacking and direct-bonding are great and lower power requirements a lot... there are still dies with stacking and no interposer! Ryzen x3d chips are a great example, v-cache is a MCM but there's no interposer there. And technically Ryzen itself (without v-cache) is also MCM too and still sees large benefits there too.

natpalmer1776 4y ago

Marketing & viral awareness go brrrrrr Edit since this was pretty low effort and likely violates the community guidelines I'll add this: I would guess the reason for seeing more content related to chiplets and their implications is due to a combination of seeing a big player adopt them for their main product line(s) and the resulting PR / marketing buzz that occurs as a result of that having 'trickle down' effects on the general industry discourse as a whole.

tdba 4y ago
Also the USG is making a big push to reshore chip manufacturing, especially in more future-facing areas such as chiplets.
- natpalmer1776 4y ago
  Took me longer than I care to admit to realize that USG stood for United States Government. Regarding the statement, I also would point out that there is an almost global push towards promoting domestic chip manufacturing and reducing the reliance on globalization of critical infrastructure, not just in the United States. In my geopolitical armchair expert opinion, I would guess this is in part caused by the conflict in Ukraine as well as rising tensions between the various 'global powers' further compounding the general loss of confidence that followed COVID-19.
  - tdba 4y ago
    This push began before Covid and well before the war in Ukraine went hot - but those two factors certainly increased the urgency. At root the push in the US began due to the rise of China as a military competitor in the early 2010s, and the consequent realization that TSMC might be blockaded, captured or destroyed.

cma 4y ago

Pentium D was a multi chip module, and so are AMD's chiplets, but Pentium D didn't use chiplets: > ICs that can perform most, if not all of the functions of a component of a computer, such as the CPU. Examples of this include implementations of IBM's POWER5 and Intel's Core 2 Quad. Multiple copies of the same IC are used to build the final product. In the case of POWER5, multiple POWER5 processors and their associated off-die L3 cache are used to build the final package. With the Core 2 Quad, effectively two Core 2 Duo dies were packaged together. > ICs that perform only some of the functions, or "Intellectual Property Blocks" ("IP Blocks"), of a component in a computer. These are known as chiplets.[3][4] An example of this are the processing ICs and I/O IC of AMD's Zen 2-based processors. https://www.wikipedia.org/wiki/Multi-chip_module https://www.wikipedia.org/wiki/Multi-chip_module It seems chiplets are a different subset but it is very similar. Also, AMD used different process nodes for different parts, where that wouldn't make sense in just a dual cpu package, and certain circuitry is now starting to scale different as process nodes shrink, so they may want a different older process node for cache than for logic, etc. which could emphasize the different functions aspect and explain why it is in the news more. 3d v-cache uses an older node for that reason, though needs more thorough connectivity than chiplet tech so uses interposers I think. You might also want to buy third-party IP that is only available created with design rules from a different foundry. Chiplets let you integrate it, where an approach like SoCs wouldn't. Shot noise is a bigger problem in EUV, so you can potentially get better yields by splitting functional components into different chiplets rather than the alternative of fusing off parts of a chip and selling it as a lower tier. Those are the reasons I see as to why they are getting lots of press and attention even though the packaging technology may be old. Initial reasons for mixing nodes may have been more business related than technical: AMD had to buy a certain amount of output from global foundries after spinning it off.

wtallis 4y ago
I think another important distinction between today's chiplet CPUs and the Pentium D/Core 2 Quad is that those early parts were still using a traditional shared front side bus connecting CPU cores to the memory controller/northbridge residing on the motherboard. So those MCMs were functionally equivalent to a dual-socket system even from a performance perspective, but harder to cool. AMD's chiplet-based CPUs gain some real benefits from using faster or lower-power short-range links that would not work between separate CPU sockets, and more advanced packaging using interposers or bridges further reduce the power and performance costs of communication between chiplets. These benefits mattered even for AMD's early chiplet-based CPUs that were homogeneous rather than using a mix of specialized dies.

dragontamer 4y ago

Interposers. The start of "modern" chiplets was AMD's R9 Nano GPU, which I believe was the first to use HBM / stacked memory. Each stack has 1024 microbumps, and the GPU has 4 stacks, meaning 4096 bumps/pins connect the GPU with its RAM. EDIT: The pitch between these microbumps is 40 microns / 0.040 milimeters. This technology is "advanced packaging", the ability to provide thousands, or even tens-of-thousands, of bumps / effective pins to serve the signals going across our computers. ------------- Yeah, chiplets or even socket-to-socket communications, have existed for decades. But today we can take advantage of thousands, tens-of-thousands, or even hundreds-of-thousands of external "pins" that connect these components together. Here's a rundown on Intel's technology: https://www.anandtech.com/show/16823/intel-accelerated-offensive-process-roadmap-updates-to-10nm-7nm-4nm-3nm-20a-18a-packaging-foundry-emib-foveros/4 https://www.anandtech.com/show/16823/intel-accelerated-offen... > Intel is also stating today that it will be using its second generation Foveros technology on the platform, implementing a bump pitch of 36 micron, effectively doubling the connection density over the first generation. 36 microns, or 36 um (micrometers) pitch density on Intel's advanced packaging technology. That's a lot of pins per mm^2! Now I don't know how these guys are lining up 0.036 milimeter bumps and reliably making connections. I kind of imagine a very tiny soldering iron, but I'm probably wrong. ------- In practice, AMD has led the way. Not only with "chiplets", but also off-die L3 cache (aka: x3d cache), adding 64MB of external SRAM to their chips through advanced packaging. So these thousands-of-microbumps are fast, reliable, and low-power enough to provide full-speed caches (something not quite possible with those earlier Pentiums you were talking about).

paulmd 4y ago
> Interposers. Interposers are just one way of packaging MCM designs. AMD's RX 7900 series doesn't use a silicon interposer, it's still an (early) MCM design (although of course it's only pulling out memory controllers and cache, not multi-GCD). And technically since it's already a fiberglass package, there's no reason you can't stick things right onto a PCB instead, it's just a matter of convenience for partners placing/routing one thing instead of 7 things. https://www.techpowerup.com/301071/amd-explains-the-economics-behind-chiplets-for-gpus https://www.techpowerup.com/301071/amd-explains-the-economic... Infinity Fanout integration is a different type of MCM integration with some of its own upsides (cost) and downsides (higher power, less bumpout). There's also bridges, and actual 3D stacks of multiple compute dies (or 2.5D with memory/etc) that don't use interposers at all. https://semiengineering.com/using-silicon-bridges-in-packages/ https://semiengineering.com/using-silicon-bridges-in-package... All of these are technically MCM - MCM is any sort of multi-chip package. MCM also really does include things like Core2Quad, Pentium-D, Crystalwell, Xenos, and various IBM modules in the 70s and 80s. The idea has been kicking around for a long time and "multi-chip module" refers to all of them collectively, not just interposer-based CPUs. https://en.wikipedia.org/wiki/Multi-chip_module https://en.wikipedia.org/wiki/Multi-chip_module And while yes, stacking and direct-bonding are great and lower power requirements a lot... there are still dies with stacking and no interposer! Ryzen x3d chips are a great example, v-cache is a MCM but there's no interposer there. And technically Ryzen itself (without v-cache) is also MCM too and still sees large benefits there too.