3 ms·

Can someone add something to " the Arm front end "?

Keyframe 4y ago
I'm interested to hear about this as well. I might be confabulating a bit, but just a bit, but I remember hearing Keller say that Zen is structured that way that there's nothing stopping them creating a different ISA frontend and say putting out an Arm processor instead of X64. That it actually wouldn't be much.
- jacquesm 4y ago
  My guess was that that was a reference to the PSP. https://en.wikipedia.org/wiki/AMD_Platform_Security_Processor https://en.wikipedia.org/wiki/AMD_Platform_Security_Processo...
  - Keyframe 4y ago
    So, AMD's IME?
    - jacquesm 4y ago
      Yes, exactly. Assuming that was what it referred to, it makes good sense to me.
  - deaddodo 4y ago
    No, AMD’s Zen had a sister uArch that was ARM-based[1]. They were originally targeting it for servers, but ended up releasing only one or two fairly bog standard ARM cores before abandoning the venture. 1 - https://en.m.wikipedia.org/wiki/AMD_K12 https://en.m.wikipedia.org/wiki/AMD_K12
    - jacquesm 4y ago
      You're right. I read the anandtech interview and it is clear that that is what he's referring to.
terafo 4y ago
Basically all high-end CPU's in the last 20 years(almost 30 actually, it started with Pentium Pro in 1995) have small internal instruction set to which all of the instructions that are transmitted to CPU are converted. Part that converts instructions to microops is called frontend. There was canceled sister-architecture to Zen called K12, which, as far as I can tell, was basically just Zen with different frontend.
- martinclayton 4y ago
  Others in the thread below have mentioned Jim Keller worked on DEC Alpha. DEC sued Intel for some patents related to Pentium, so even this bit of the history relates back to Jim somewhat.
  - paulmd 4y ago
    Jim Keller is tied to basically every ground-breaking architecture of the last 30 years. Not that everything he's worked on has been a hit, but, if something ended up being a huge success there's a high probability Jim Keller has been skulking around somewhere. Conroe/Sandy Bridge are the only ones that come to mind that haven't been him. His greatest hits: DEC Alpha, AMD K7 (Thunderbird/Athlon), AMD K8 (Athlon 64), Apple A5, AMD Zen... probably others I'm forgetting. Like god damn can someone else in the industry have some ideas of their own please, lol /s And again not that other people aren't involved either, in particular Mike Clark was really the guy who executed Zen development, but Keller was there at least as an advisor for a lot of the early development. He's one of Zen's uncles, Clark is the father. https://www.youtube.com/watch?v=3vyNzgOP5yw https://www.youtube.com/watch?v=3vyNzgOP5yw I think it also says a lot that he completely fucking bailed from Intel after only being there a couple months... I think he saw they just weren't ready/willing to execute well and his time would be wasted there. He's the wandering silicon samurai who drops some golden nuggets of advice and wanders off into the sunset, not a babysitter while you purge middle-managers playing office politics. (He left due to a "family situation" and while I have no doubt that it was real... I also think he probably might have stayed if Intel wasn't a complete dumpster fire too.)
    - 4y ago

I'm interested to hear about this as well. I might be confabulating a bit, but just a bit, but I remember hearing Keller say that Zen is structured that way that there's nothing stopping them creating a different ISA frontend and say putting out an Arm processor instead of X64. That it actually wouldn't be much.

jacquesm 4y ago
My guess was that that was a reference to the PSP. https://en.wikipedia.org/wiki/AMD_Platform_Security_Processor https://en.wikipedia.org/wiki/AMD_Platform_Security_Processo...
- Keyframe 4y ago
  So, AMD's IME?
  - jacquesm 4y ago
    Yes, exactly. Assuming that was what it referred to, it makes good sense to me.
- deaddodo 4y ago
  No, AMD’s Zen had a sister uArch that was ARM-based[1]. They were originally targeting it for servers, but ended up releasing only one or two fairly bog standard ARM cores before abandoning the venture. 1 - https://en.m.wikipedia.org/wiki/AMD_K12 https://en.m.wikipedia.org/wiki/AMD_K12
  - jacquesm 4y ago
    You're right. I read the anandtech interview and it is clear that that is what he's referring to.

terafo 4y ago

Basically all high-end CPU's in the last 20 years(almost 30 actually, it started with Pentium Pro in 1995) have small internal instruction set to which all of the instructions that are transmitted to CPU are converted. Part that converts instructions to microops is called frontend. There was canceled sister-architecture to Zen called K12, which, as far as I can tell, was basically just Zen with different frontend.

martinclayton 4y ago
Others in the thread below have mentioned Jim Keller worked on DEC Alpha. DEC sued Intel for some patents related to Pentium, so even this bit of the history relates back to Jim somewhat.
- paulmd 4y ago
  Jim Keller is tied to basically every ground-breaking architecture of the last 30 years. Not that everything he's worked on has been a hit, but, if something ended up being a huge success there's a high probability Jim Keller has been skulking around somewhere. Conroe/Sandy Bridge are the only ones that come to mind that haven't been him. His greatest hits: DEC Alpha, AMD K7 (Thunderbird/Athlon), AMD K8 (Athlon 64), Apple A5, AMD Zen... probably others I'm forgetting. Like god damn can someone else in the industry have some ideas of their own please, lol /s And again not that other people aren't involved either, in particular Mike Clark was really the guy who executed Zen development, but Keller was there at least as an advisor for a lot of the early development. He's one of Zen's uncles, Clark is the father. https://www.youtube.com/watch?v=3vyNzgOP5yw https://www.youtube.com/watch?v=3vyNzgOP5yw I think it also says a lot that he completely fucking bailed from Intel after only being there a couple months... I think he saw they just weren't ready/willing to execute well and his time would be wasted there. He's the wandering silicon samurai who drops some golden nuggets of advice and wanders off into the sunset, not a babysitter while you purge middle-managers playing office politics. (He left due to a "family situation" and while I have no doubt that it was real... I also think he probably might have stayed if Intel wasn't a complete dumpster fire too.)
  - 4y ago