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What node is AMD IO die now a days? It always felt like they were keeping the IO dia one node backward to honor the GF agreement. Even with this they are able t

What node is AMD IO die now a days? It always felt like they were keeping the IO dia one node backward to honor the GF agreement. Even with this they are able to give 128 PCIe lanes and Better Memory frequency. So when they are able to bring IO die also to leading node, it is going to be awesome.

MrFoof 5y ago
The AMD IO die is using the GloFo 14nm process.
exmadscientist 5y ago
Not as awesome as you think. The IOD is on the older process because it benefits comparatively little from transistor shrinks. (Logic-level IO transistors have to be physically large, with thicker gate oxides.) But it will help some.
- monocasa 5y ago
  It might not help at all from a density perspective. The IO die has a lot of pads along the edges that can't be shrunk which puts a lower limit on die area. I wouldn't be surprised if the logic areas in the middle already have a lot of blank space at 14nm. You used to see the same thing with north bridge chips, and that's basically what the IO die is anyway.
  - robocat 5y ago
    > The IO die has a lot of pads along the edges that can't be shrunk which puts a lower limit on die area. Are you just imagining things? This article includes an image of the 14nm die, along with the functional breakdown further down the article: https://www.tomshardware.com/news/amd-64-core-epyc-cpu-die-design-architecture-ryzen-3000 https://www.tomshardware.com/news/amd-64-core-epyc-cpu-die-d...
    - monocasa 5y ago
      I'm not. Your citation shows extremely dense pads in two banks (even before taking power delivery into account which isn't shown in your functional breakdown), and decent amounts of empty space between the logic blocks.
  - exmadscientist 5y ago
    Density-wise, no, probably not. But you'll get faster SERDES and should be able to improve the internal routers/crossbars, which contain more logic than you'd think. But, yeah, there isn't a lot there. When the higher cost per area is considered (just count the number of bloody masks...) it's probably a net loss.
- fomine3 5y ago
  But Milan's IOD consumers a lot of power even if it's idle. Next EPYC will come with DDR5 and PCIe 5 so it getting much worse. https://www.anandtech.com/show/16529/amd-epyc-milan-review/5 https://www.anandtech.com/show/16529/amd-epyc-milan-review/5

MrFoof 5y ago

The AMD IO die is using the GloFo 14nm process.

exmadscientist 5y ago

Not as awesome as you think. The IOD is on the older process because it benefits comparatively little from transistor shrinks. (Logic-level IO transistors have to be physically large, with thicker gate oxides.) But it will help some.

monocasa 5y ago
It might not help at all from a density perspective. The IO die has a lot of pads along the edges that can't be shrunk which puts a lower limit on die area. I wouldn't be surprised if the logic areas in the middle already have a lot of blank space at 14nm. You used to see the same thing with north bridge chips, and that's basically what the IO die is anyway.
- robocat 5y ago
  > The IO die has a lot of pads along the edges that can't be shrunk which puts a lower limit on die area. Are you just imagining things? This article includes an image of the 14nm die, along with the functional breakdown further down the article: https://www.tomshardware.com/news/amd-64-core-epyc-cpu-die-design-architecture-ryzen-3000 https://www.tomshardware.com/news/amd-64-core-epyc-cpu-die-d...
  - monocasa 5y ago
    I'm not. Your citation shows extremely dense pads in two banks (even before taking power delivery into account which isn't shown in your functional breakdown), and decent amounts of empty space between the logic blocks.
- exmadscientist 5y ago
  Density-wise, no, probably not. But you'll get faster SERDES and should be able to improve the internal routers/crossbars, which contain more logic than you'd think. But, yeah, there isn't a lot there. When the higher cost per area is considered (just count the number of bloody masks...) it's probably a net loss.
fomine3 5y ago
But Milan's IOD consumers a lot of power even if it's idle. Next EPYC will come with DDR5 and PCIe 5 so it getting much worse. https://www.anandtech.com/show/16529/amd-epyc-milan-review/5 https://www.anandtech.com/show/16529/amd-epyc-milan-review/5