"In consolation, Qualcomm today appears to be looking at in-house core designs again. In 2021, they acquired a CPU startup called Nuvia. Meanwhile, ARM Ltd has been tightening up licensing agreements in the face of financial issues. They’ve even sued Qualcomm to halt Nuvia’s efforts and keep a tight grip on players within the ARM ecosystem. Qualcomm certainly has the motivation to safeguard Snapdragon’s future by bringing core development back in-house. If the stars align, perhaps Nuvia’s efforts will give Qualcomm another in-house core some time within the current millennium."
That's the conclusion of the article you are commenting on.
It is most likely based on the A72. Qcom purchased an ARM architecture level license, which grants it access to the design of ARM CPUs and allows it to make changes and sell the resulting product. This is what Kryo most certainly is.
This is how Apple started doing ARM CPU designs as well.
According to the article, the original Kryo was a Qualcomm design but they're using the same branding for ARM CPU designs now.
Plus original Kryo seems to be more than sufficiently different on pretty much every axis that if it -was- in part based on an ARM design I'm not sure how much of said design would be left.
(people curious about this should probably read the whole thing though since this isn't exactly my area)
(author here) It is not based on A72. Kryo doesn't have anything in common with A72 besides understanding the same instructions. I covered that in detail in the article. Kryo is wider and has a very different out of order engine than A72.
Not mentioned was that it doesn't inherit a lot of A72's quirks. For example, A72 has peculiar decode restrictions. It can only handle one NOP per clock, and NOPs somehow consume out of order resources beyond just a ROB entry. Kryo has none of these weird characteristics.
It appears that this article is confusing Qualcomm's Krait architecture with Kryo:
"Qualcomm did the same up to 2016 with the Kryo architecture."
That timing is very much wrong.
"[Krait] was introduced in 2012 as a successor to the Scorpion CPU and although it has architectural similarities, Krait is not a Cortex-A15 core, but it was designed in-house.[1] In 2015, Krait was superseded by the 64-bit Kryo architecture, first introduced in Snapdragon 820 SoC."
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[ 3.9 ms ] story [ 26.3 ms ] threadThat's the conclusion of the article you are commenting on.
It is most likely based on the A72. Qcom purchased an ARM architecture level license, which grants it access to the design of ARM CPUs and allows it to make changes and sell the resulting product. This is what Kryo most certainly is.
This is how Apple started doing ARM CPU designs as well.
Plus original Kryo seems to be more than sufficiently different on pretty much every axis that if it -was- in part based on an ARM design I'm not sure how much of said design would be left.
(people curious about this should probably read the whole thing though since this isn't exactly my area)
Not mentioned was that it doesn't inherit a lot of A72's quirks. For example, A72 has peculiar decode restrictions. It can only handle one NOP per clock, and NOPs somehow consume out of order resources beyond just a ROB entry. Kryo has none of these weird characteristics.
"Qualcomm did the same up to 2016 with the Kryo architecture."
That timing is very much wrong.
"[Krait] was introduced in 2012 as a successor to the Scorpion CPU and although it has architectural similarities, Krait is not a Cortex-A15 core, but it was designed in-house.[1] In 2015, Krait was superseded by the 64-bit Kryo architecture, first introduced in Snapdragon 820 SoC."
https://en.m.wikipedia.org/wiki/Krait_(processor)