6 ms·

Probably the MSR_TURBO_POWER_LIMIT value as described in https://www.reddit.com/r/macbookpro/comments/91256u/optimal_cpu_tuning_settings_for_i9_mbp_to_stop/ htt

Probably the MSR_TURBO_POWER_LIMIT value as described in https://www.reddit.com/r/macbookpro/comments/91256u/optimal_cpu_tuning_settings_for_i9_mbp_to_stop/ https://www.reddit.com/r/macbookpro/comments/91256u/optimal_...

aroman 8y ago
That analysis is incredible, how was the OP able to figure all of that out!?
- baybal2 8y ago
  Intel's HDK docs?
- DavideNL 8y ago
  I don't know, but apparently (1): >> Originally posted at MacRumors by winterny >> https://forums.macrumors.com/threads/optimal-cpu-tuning-settings-for-i9-mbp-to-stop-vrm-throttling-explanation-of-apples-engineering-f.2128936/ https://forums.macrumors.com/threads/optimal-cpu-tuning-sett... 1. https://news.ycombinator.com/item?id=17602455 https://news.ycombinator.com/item?id=17602455
  - DuskStar 8y ago
    The Reddit post was about 20 minutes earlier.
- old-gregg 8y ago
  I've experienced some early adopter pains with the desktop version of this CPU (x299 platform) when it came out and I used linux kernel mailing list to search for answers. I was surprised how easy it was to read the code of the related kernel modules and interact with their authors (Intel engineers). These "magic codes" are probably just #define macros somewhere in the kernel repo, in my case it was in [1] [1] https://github.com/torvalds/linux/tree/master/drivers/platform/x86 https://github.com/torvalds/linux/tree/master/drivers/platfo...
- AdamJacobMuller 8y ago
  Lots and lots of testing and lots of reading intel docs / example code on the internet. I probably ran cinebench and prime95 about 2000 times in the past few days.
- ddalex 8y ago
  If you're designing hardware, this is a thing that people know. The new Xps machines have the same VMR problem. Probably he tested for a known problem and bingo! I wonder if the discoverer works for any hardware design company.
ordinaryradical 8y ago
If you read that thread, what's curious is that it seems this power threshold has always been set perilously because older MacBooks seem to have the same setting for their VRMs as well.
- cptskippy 8y ago
  I would expect this sort of slip from Dell or Lenovo with like 1200 skus but Apple really only has a handful.

aroman 8y ago

That analysis is incredible, how was the OP able to figure all of that out!?

baybal2 8y ago
Intel's HDK docs?
DavideNL 8y ago
I don't know, but apparently (1): >> Originally posted at MacRumors by winterny >> https://forums.macrumors.com/threads/optimal-cpu-tuning-settings-for-i9-mbp-to-stop-vrm-throttling-explanation-of-apples-engineering-f.2128936/ https://forums.macrumors.com/threads/optimal-cpu-tuning-sett... 1. https://news.ycombinator.com/item?id=17602455 https://news.ycombinator.com/item?id=17602455
- DuskStar 8y ago
  The Reddit post was about 20 minutes earlier.
old-gregg 8y ago
I've experienced some early adopter pains with the desktop version of this CPU (x299 platform) when it came out and I used linux kernel mailing list to search for answers. I was surprised how easy it was to read the code of the related kernel modules and interact with their authors (Intel engineers). These "magic codes" are probably just #define macros somewhere in the kernel repo, in my case it was in [1] [1] https://github.com/torvalds/linux/tree/master/drivers/platform/x86 https://github.com/torvalds/linux/tree/master/drivers/platfo...
AdamJacobMuller 8y ago
Lots and lots of testing and lots of reading intel docs / example code on the internet. I probably ran cinebench and prime95 about 2000 times in the past few days.
ddalex 8y ago
If you're designing hardware, this is a thing that people know. The new Xps machines have the same VMR problem. Probably he tested for a known problem and bingo! I wonder if the discoverer works for any hardware design company.

ordinaryradical 8y ago

If you read that thread, what's curious is that it seems this power threshold has always been set perilously because older MacBooks seem to have the same setting for their VRMs as well.

cptskippy 8y ago
I would expect this sort of slip from Dell or Lenovo with like 1200 skus but Apple really only has a handful.