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Recent story on the de-liding of the AMD Threadripper.
It's not what you would expect. Most people thought, "oh, its a Ryzen 3 x 4". Think subtraction, its an Epyc minus 2!
Per ExtremeTech:
AMD Threadripper Delidded, With a Multi-Core Surprise Under the Hood
Now, veteran high-end overclocker der8auer has moved over to the Threadripper side of the equation. The first thing to know is that AMD, unlike Intel, is specifically using solder in Threadripper, whereas Intel’s 10-core Core i9-7900X doesn’t use it. The second is that Threadripper has a different CPU configuration under that solder than we would’ve expected.
According to der8auer, who spoke with AMD, Threadripper is an Epyc CPU configuration with four dies, each packing eight cores. At first, we thought this meant AMD had gone for a similar arrangement to what it used for Ryzen 3: four cores active on each die (with SMT enabled in this case) and 16 cores/32 threads on the entire chip. But that’s not the case if der8auer’s information is accurate. According to him, Threadripper only uses two of the four Ryzen dies mounted on the PCB. The other two aren’t functional. His video on the topic is embedded below.
This seems rather odd for a host of reasons. Generally speaking, the entire point of using an MCM (Multi-Chip Module), as opposed to a unified die, is so you can leave chips off the product. If you think about it, this makes perfect sense: You don’t want to build a 32-core part only to find out that your yield at that enormous die size and power consumption is too low to make the chips profitable. It’s economically much safer to build and mount 4×8-core CPUs than to build one unified 32-core CPU. If AMD were offering Threadripper with just two cores active in every CCX, it would probably help with hot spot formation and allow AMD to selectively choose the very highest clocking cores. Instead, we’ve got a situation where it apparently made sense for AMD to mount four cores, but only activate two of them.
The only explanation I’ve come up with is that this is related to AMD’s economies of scale and manufacturing costs. AMD doesn’t own its packaging and test facility anymore, and its Epyc design costs aren’t going to be immediately replaced by Epyc revenue. AMD has stated that while it’s targeting a 10-percent server market share, it doesn’t expect to hit that this year. By tossing expected Threadripper sales in alongside Epyc sales, AMD may have cut its overall costs by improving its economy of scale.
It's not what you would expect. Most people thought, "oh, its a Ryzen 3 x 4". Think subtraction, its an Epyc minus 2!
Per ExtremeTech:
AMD Threadripper Delidded, With a Multi-Core Surprise Under the Hood
Now, veteran high-end overclocker der8auer has moved over to the Threadripper side of the equation. The first thing to know is that AMD, unlike Intel, is specifically using solder in Threadripper, whereas Intel’s 10-core Core i9-7900X doesn’t use it. The second is that Threadripper has a different CPU configuration under that solder than we would’ve expected.
According to der8auer, who spoke with AMD, Threadripper is an Epyc CPU configuration with four dies, each packing eight cores. At first, we thought this meant AMD had gone for a similar arrangement to what it used for Ryzen 3: four cores active on each die (with SMT enabled in this case) and 16 cores/32 threads on the entire chip. But that’s not the case if der8auer’s information is accurate. According to him, Threadripper only uses two of the four Ryzen dies mounted on the PCB. The other two aren’t functional. His video on the topic is embedded below.
This seems rather odd for a host of reasons. Generally speaking, the entire point of using an MCM (Multi-Chip Module), as opposed to a unified die, is so you can leave chips off the product. If you think about it, this makes perfect sense: You don’t want to build a 32-core part only to find out that your yield at that enormous die size and power consumption is too low to make the chips profitable. It’s economically much safer to build and mount 4×8-core CPUs than to build one unified 32-core CPU. If AMD were offering Threadripper with just two cores active in every CCX, it would probably help with hot spot formation and allow AMD to selectively choose the very highest clocking cores. Instead, we’ve got a situation where it apparently made sense for AMD to mount four cores, but only activate two of them.
The only explanation I’ve come up with is that this is related to AMD’s economies of scale and manufacturing costs. AMD doesn’t own its packaging and test facility anymore, and its Epyc design costs aren’t going to be immediately replaced by Epyc revenue. AMD has stated that while it’s targeting a 10-percent server market share, it doesn’t expect to hit that this year. By tossing expected Threadripper sales in alongside Epyc sales, AMD may have cut its overall costs by improving its economy of scale.