Because with SMT disabled, the Graviton2 comes out looking pretty bad. If they enable SMT on x86 they can say that their cores are roughly as good as threads on x86.
Of course Graviton2 has lower IPC than Zen2. It's based on weak A76 from 2018. But it has core area of 1.4mm2 what allows to put twice as much cores than Zen2 (3.6mm2). Wait for 128-core Graviton3 based on A78 (30% more IPC while less -5% transistors). And prey for that they will not use Cortex X1 cores (60% higher IPC (40% more than Zen2) at 2.1mm2 area). How about that. Still looking x86 strong?
I never made any claim about >50% of servers running with SMT off, just that more and more server customers are getting their servers like that. I don't have any industry-wide stats, just anecdotes that seem to be going one way.
As for reason for silence, some of us actually work with this stuff, so we don't have time to post on the forums about it every single day.
This claim did
@LightningZ71 . He is silent because he cannot prove his crazy claim. When you work with the stuff I'd like to know numbers from your company. Just give us number of machines and how many of them is running SMT OFF.
We could have 8xALU, 4xAGU, 4xFPU, SMT4 CPU core in 2003, what a shame. If Zen3 isn't Keller's EV8 resurrection then AMD is in deep deep trouble. I hope Zen3 is at least 6xALU, 3xAGU, 4xFPU, SMT4.
AMD needs to bring more tech features and go forward. However we know they can go also backward like with Bulldozer. So who knows :/