Question zen3 core ordering

Soulkeeper

Diamond Member
Nov 23, 2001
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I was wondering what the correct ordering is for zen3 on the die.

I created this image to be what I think it might be:
zen3-core-layout-01.png

Can anyone verify which is the correct ordering ?
IE: inside the bios curve offsets for core 0-15 will correspond to which cores.
Thanks
 

Bigos

Member
Jun 2, 2019
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If you have access to the CPU you can check apic IDs of each core. Iirc the lowest bit is the thread number, the next 3 bits on zen 3 should be the core number within ccx and then would be the ccx number (then package number if you have multiple sockets).

Note that on Linux apic ID != core number. /proc/cpuinfo shows the ID of each core.

I don't know which core number within ccx is which though.
 

Soulkeeper

Diamond Member
Nov 23, 2001
6,699
132
106
It's amazing that no pictures online show the actual ordering.
I know they can disable any core they want at the factory, influencing the ordering.
But I imagine it's not random.

Basically, what i'm wondering is if they order from top/bottom or right/left on the actual physical die. They could be alternate from right/left side. My picture is just one of several possible orderings.
 

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