- cross-posted to:
- phoronix@lemmy.world
- cross-posted to:
- phoronix@lemmy.world
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I couldn’t find a hard answer to whether this supports EPYC only, or Ryzen too; so I put together this script to read the CPUID to detect for
INVLPGBsupport according to the AMD64 Programmer’s Manual, and my 7800X3D does not supportINVLPGB.(Let me know if I’ve made an error though!)
Code
#include <stdio.h> #include <stdint.h> int main() { uint32_t eax, ebx, ecx, edx; eax = 0x80000008; __asm__ __volatile__ ( "cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (eax) ); printf("EBX: 0x%x\n", ebx); if (ebx & (1 << 3)) { printf("CPU supports INVLPGB\n"); } else { printf("CPU does not support INVLPGB\n"); } return 0; }I can’t keep up with the architecture family lines; is the Ryzen 7 5800 series on the Zen 3 line?
Assuming you’re talking about the 5800x, yes.
Sweet. They’re laptop CPUs, right? Last year, after more than a decade of owning only laptops, I bought two of those micro-PC boxes - mine were Trigkey, but I saw nearly identical ones under other brand names. 16 cores, expandable RAM and NVME… utterly blew my latest 2y/o laptop out of the water, especially after I put 64GB of RAM in one in an orgy of entering a new market of cheap components.
And now this. I’m loving it.
No, the 5800x and x3d are desktop CPUs.
😥
5800H
That’s
INVLPGwhich has been there since the 486. The AMD64 Programmer’s Manual has some info on the differences betweenINVLPG,INVLPGA, andINVLPGBthough.
Huge speed-ups for the
will-it-scale tlb_flush2_threadstest - presumably not very representative!I wonder how much effect it has on real world workloads.
