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> zen 2 has better IPC Ice Lake has better IPC. The only issue with Ice Lake is that it's on a broken 10nm process, which primarily means that clocks are terri

> zen 2 has better IPC Ice Lake has better IPC. The only issue with Ice Lake is that it's on a broken 10nm process, which primarily means that clocks are terrible. > Source for this? https://en.wikichip.org/wiki/intel/microarchitectures/skylake_(client) https://en.wikichip.org/wiki/intel/microarchitectures/skylak... https://en.wikichip.org/wiki/amd/microarchitectures/zen_2 https://en.wikichip.org/wiki/amd/microarchitectures/zen_2 Both have a 224 entry ROB, 92 vs. 97 entry scheduler, 180 entry PRF, 168 vs. 160 FP PRF, same number of integer ALUs, similar load/store width, 72 in-flight loads, 56 vs. 48 in-flight stores, etc. Consequently they perform within margins of each other. They're about as minimally different as competitors' products can be. Contrast to something like Arm's or Apple's cores, which are qualitatively different products, both to each other and to any of Intel or AMD's chips.

gruez 6y ago
>Ice Lake has better IPC. my apologies, got the lake names mixed up. >Both have a 224 entry ROB, 92 vs. 97 entry scheduler, 180 entry PRF, 168 vs. 160 FP PRF, same number of integer ALUs, similar load/store width, 72 in-flight loads, 56 vs. 48 in-flight stores, etc. They have similar metrics, that doesn't mean they're copies of each other. The underlying designs are most certainly different (eg. chiplet vs monolithic). The reason they have similar in those metrics is probably due to convergent design, ie. these combination of functional units provide the best performance to transistor ratio. You see this in nature too. eg. https://en.wikipedia.org/wiki/Convergent_evolution#Opposable_thumbs https://en.wikipedia.org/wiki/Convergent_evolution#Opposable..., which look similar at a high level, but are actually different in implementation.
- Veedrac 6y ago
  AMD's previous design was its own thing. Arm's and Apple's designs are their own things. There's still flexibility in how to build a core. Skylake is clearly not even the optimal target; Apple's approach easily outclasses it, for instance. And yet AMD did none of that; they build a core that is practically just Skylake, with no real innovation I can spot anywhere. There's nothing wrong with this as a strategy. AMD's own designs were performing pretty badly and Skylake was a straightforward, reliable target that would lead them back to competitiveness. Their uncore is plenty innovative, given their willingness to compete on scale. But a rose is a rose is a rose. Zen 2 is arguably more similar to Skylake than Ice Lake is to Skylake.

gruez 6y ago

>Ice Lake has better IPC. my apologies, got the lake names mixed up. >Both have a 224 entry ROB, 92 vs. 97 entry scheduler, 180 entry PRF, 168 vs. 160 FP PRF, same number of integer ALUs, similar load/store width, 72 in-flight loads, 56 vs. 48 in-flight stores, etc. They have similar metrics, that doesn't mean they're copies of each other. The underlying designs are most certainly different (eg. chiplet vs monolithic). The reason they have similar in those metrics is probably due to convergent design, ie. these combination of functional units provide the best performance to transistor ratio. You see this in nature too. eg. https://en.wikipedia.org/wiki/Convergent_evolution#Opposable_thumbs https://en.wikipedia.org/wiki/Convergent_evolution#Opposable..., which look similar at a high level, but are actually different in implementation.

Veedrac 6y ago
AMD's previous design was its own thing. Arm's and Apple's designs are their own things. There's still flexibility in how to build a core. Skylake is clearly not even the optimal target; Apple's approach easily outclasses it, for instance. And yet AMD did none of that; they build a core that is practically just Skylake, with no real innovation I can spot anywhere. There's nothing wrong with this as a strategy. AMD's own designs were performing pretty badly and Skylake was a straightforward, reliable target that would lead them back to competitiveness. Their uncore is plenty innovative, given their willingness to compete on scale. But a rose is a rose is a rose. Zen 2 is arguably more similar to Skylake than Ice Lake is to Skylake.