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To be fair, it's more "AMD reached parity" while on smaller node (big advantage that presumably will be matched soon-ish). The thread superiority is due to inte

by ivalm 7y ago

To be fair, it's more "AMD reached parity" while on smaller node (big advantage that presumably will be matched soon-ish). The thread superiority is due to intel locking SMT for market segmentation reasons. In terms of raw core performance AMD has some IPC advantage but lower clocks and higher latency leading to very mixed results. The big question is if Intel can finally transition to lower node for their larger chips. If the answer is yes, AMD will have to work hard to maintain parity, if the answer is no, AMD might actually develop a meaningful lead.

hajile 7y ago
Zen 1 CCX is 60mm^2 (cores + L3) and 1.4B transistors. That is 373M transistors for L3 and 1.03B for cores/L1/L2. Zen 2 CCX is 31.3mm^2 according to AMD's slides. The Zen 2 chip is 74mm^2 and 3.9B transistors. We can use this to get the transistors per mm^2 and multiply by the size of the Zen 2 CCX to get a transistor count of 1.65B. Something is weird about these numbers. We go from 1.4B to 1.65B transistors. That seems "reasonable", but something is wrong with our cache figures. Zen 2 has 2x as much L3 cache and the L3 on Zen 1 takes 373M transistors. If we just double that, then Zen 1 is actually larger at 1.77B transistors. If we assume they simply didn't count the extra L3 and attempt to add it back, we get over 4B transistors for the chip when it's only 3.9B transistors (including uncore things like Infinity Fabric). Any way you look at it though, Zen 2 cores can't have many more transistors than their 12nm counterparts, so the node obviously isn't what makes Zen 2 work. Also keep in mind that the 74mm^2 cores are smaller than the 125mm^2 IO Die which is on 12nm. The die shrink was mostly about power savings and fitting two chiplets + IO die on the AM4 package. That said, Intel's 8-core chip is around 175mm^2 (they quit releasing those numbers about the time the 10nm fiasco started). Zen on 14nm was 215mm^2 (keep in mind that Intel's 14nm is roughly equivalent to TSMC's 10nm). AMD's part comes out bigger at the 8-core mark, but things change when we start looking at their larger chips. 10 core Skylake is 322mm^2 and 18-core is 484mm^2. Adjusting for the extra transistors in the zen 2 CCX, Zen 1 would be around 235mm^2 at 14nm. Shrinking to 10nm would give a chip smaller than Intels, but also without an integrated GPU. I'd guess they are about equal in transistor count which means Intel isn't super likely to pull ahead even if they could get 10nm working. https://www.anandtech.com/show/14525/amd-zen-2-microarchitecture-analysis-ryzen-3000-and-epyc-rome/5 https://www.anandtech.com/show/14525/amd-zen-2-microarchitec... https://www.tomshardware.com/reviews/ryzen-9-3900x-7-3700x-review,6214.html https://www.tomshardware.com/reviews/ryzen-9-3900x-7-3700x-r... https://en.wikichip.org/wiki/amd/microarchitectures/zen#Zeppelin https://en.wikichip.org/wiki/amd/microarchitectures/zen#Zepp...

by ivalm 7y ago

hajile 7y ago

Zen 1 CCX is 60mm^2 (cores + L3) and 1.4B transistors. That is 373M transistors for L3 and 1.03B for cores/L1/L2. Zen 2 CCX is 31.3mm^2 according to AMD's slides. The Zen 2 chip is 74mm^2 and 3.9B transistors. We can use this to get the transistors per mm^2 and multiply by the size of the Zen 2 CCX to get a transistor count of 1.65B. Something is weird about these numbers. We go from 1.4B to 1.65B transistors. That seems "reasonable", but something is wrong with our cache figures. Zen 2 has 2x as much L3 cache and the L3 on Zen 1 takes 373M transistors. If we just double that, then Zen 1 is actually larger at 1.77B transistors. If we assume they simply didn't count the extra L3 and attempt to add it back, we get over 4B transistors for the chip when it's only 3.9B transistors (including uncore things like Infinity Fabric). Any way you look at it though, Zen 2 cores can't have many more transistors than their 12nm counterparts, so the node obviously isn't what makes Zen 2 work. Also keep in mind that the 74mm^2 cores are smaller than the 125mm^2 IO Die which is on 12nm. The die shrink was mostly about power savings and fitting two chiplets + IO die on the AM4 package. That said, Intel's 8-core chip is around 175mm^2 (they quit releasing those numbers about the time the 10nm fiasco started). Zen on 14nm was 215mm^2 (keep in mind that Intel's 14nm is roughly equivalent to TSMC's 10nm). AMD's part comes out bigger at the 8-core mark, but things change when we start looking at their larger chips. 10 core Skylake is 322mm^2 and 18-core is 484mm^2. Adjusting for the extra transistors in the zen 2 CCX, Zen 1 would be around 235mm^2 at 14nm. Shrinking to 10nm would give a chip smaller than Intels, but also without an integrated GPU. I'd guess they are about equal in transistor count which means Intel isn't super likely to pull ahead even if they could get 10nm working. https://www.anandtech.com/show/14525/amd-zen-2-microarchitecture-analysis-ryzen-3000-and-epyc-rome/5 https://www.anandtech.com/show/14525/amd-zen-2-microarchitec... https://www.tomshardware.com/reviews/ryzen-9-3900x-7-3700x-review,6214.html https://www.tomshardware.com/reviews/ryzen-9-3900x-7-3700x-r... https://en.wikichip.org/wiki/amd/microarchitectures/zen#Zeppelin https://en.wikichip.org/wiki/amd/microarchitectures/zen#Zepp...