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What's amazing (to me anyway, as I learn more about the fab game) is how Zen could suffer the exact same defects per wafer as Intel and produce considerably mor

What's amazing (to me anyway, as I learn more about the fab game) is how Zen could suffer the exact same defects per wafer as Intel and produce considerably more viable CPUs per wafer. The "Core Complex" or chiplet architecture was such a brilliant longterm play by AMD—it still blows my mind.

dragontamer 8y ago
The difference is closer than you'd imagine. Intel's XCC die is 694mm^2 for a 28-core, while Zen / Zeppelin is 213mm^2 for an 8-core. Intel's XCC 28 core is around 25mm^2 per core, while AMD's Zen is 26.6mm^2 per core... suggesting a slight advantage to Intel! Furthermore: Intel's XCC die has 28-cores. When defects come into XCC, Intel can simply disable those cores and sell them for cheaper. For example, Intel's Xeon Platinum 8160 is a 24-core. Presumably, 4-cores are defective but Intel can still sell it for $5000 or so. So a defective product would require a manufacturing defect somewhere critical. But individual cores can most certainly be disabled during the manufacturing process and sold as a lower tier product, like the Xeon Platinum 8160 As such, Intel definitely has good yields, at least on 14nm production. ------------ The main advantage is that AMD's strategy works way better when yields are poor due to a new process being not fully understood. But as defect rates drop, Intel's monolithic strategy seems to have slight advantages over AMD's. (Remember: Intel's cores are slightly superior in IPC, have slightly faster caches, and AVX512 enabled). AMD's strategy is definitely good, but I don't think Intel is really that far behind.
- MrRadar 8y ago
  In addition to the benefits of getting working more working chips per wafer, don't chiplets also provide the benefit of being able to independently bin each chiplet, significantly increasing the effective production yield of high-clocking high core count chips relative to monolithic fabrication?
catdog 8y ago
Intel did not have a lot of competition in recent years so why design for maximum yield when you can just slap a high price tag on the thing? AMD on the other hand needed to assume that they would not be able to compete in raw performance so what's left is being as cost effective as possible.

dragontamer 8y ago

The difference is closer than you'd imagine. Intel's XCC die is 694mm^2 for a 28-core, while Zen / Zeppelin is 213mm^2 for an 8-core. Intel's XCC 28 core is around 25mm^2 per core, while AMD's Zen is 26.6mm^2 per core... suggesting a slight advantage to Intel! Furthermore: Intel's XCC die has 28-cores. When defects come into XCC, Intel can simply disable those cores and sell them for cheaper. For example, Intel's Xeon Platinum 8160 is a 24-core. Presumably, 4-cores are defective but Intel can still sell it for $5000 or so. So a defective product would require a manufacturing defect somewhere critical. But individual cores can most certainly be disabled during the manufacturing process and sold as a lower tier product, like the Xeon Platinum 8160 As such, Intel definitely has good yields, at least on 14nm production. ------------ The main advantage is that AMD's strategy works way better when yields are poor due to a new process being not fully understood. But as defect rates drop, Intel's monolithic strategy seems to have slight advantages over AMD's. (Remember: Intel's cores are slightly superior in IPC, have slightly faster caches, and AVX512 enabled). AMD's strategy is definitely good, but I don't think Intel is really that far behind.

MrRadar 8y ago
In addition to the benefits of getting working more working chips per wafer, don't chiplets also provide the benefit of being able to independently bin each chiplet, significantly increasing the effective production yield of high-clocking high core count chips relative to monolithic fabrication?

catdog 8y ago

Intel did not have a lot of competition in recent years so why design for maximum yield when you can just slap a high price tag on the thing? AMD on the other hand needed to assume that they would not be able to compete in raw performance so what's left is being as cost effective as possible.