Thanks for the dmesg. Yes you have 2 performance cores (with SMT enabled makes 4) and 8 efficient cores. I would use hw.blockcpu=L so you get to use all those E cores and don’t bottleneck your laptop to just 2 P cores. The P to E ratio is 76% for turbo frequency (5 GHz vs 3.8 GHz) and 64% for base frequency (1.4 GHz vs 900 MHz). That’s not too bad and you probably won’t notice anything.
> On Sep 2, 2026, at 2:09 PM, Ronny Machado <[email protected]> wrote: > > Thanks, that's what I was asking for...anyway, dmesg attached justi in case. > > -- > > R. > > Sent with Proton Mail secure email. > >> On Wednesday, September 2nd, 2026 at 1:56 PM, Brian Brombacher >> <[email protected]> wrote: >> >> Including a dmesg would be helpful here. >> >> My guess is you have a CPU with 4 performance/smt cores and 8 efficient >> cores. Setting hw.blockcpu=E means to block the use of the 8 efficient >> cores. Setting hw.blockcpu=L means to block lethargic cores, which you have >> zero of, so the end result is you get access to all 12 cores on your CPU. >> >> It all depends on what you want to achieve. If you don’t mind having >> processes move between performance and efficient cores, then blocking L or >> none would be fine. If you want to ensure deterministic processing power, >> then block E or EL (again, you have no lethargic cores so it doesn’t matter >> if you include L or not). If your laptop runs fine with hw.blockcpu=L, then >> use that. Again a dmesg would help us determine what kind of processor you >> have and therefore how severe the performance degradation is between P and E >> cores. >> >> >>>> On Sep 2, 2026, at 1:20 PM, Ronny Machado <[email protected]> wrote: >>> >>> >>> Okay, this may be a silly question, since 7.9 (which I've been using since >>> day one) I still don't quite understand the advantages of hw.blockcpu. >>> >>> In announcements: >>> >>> "Various kernel improvements: >>> Introduced a mechanism to manage CPU cores with different speeds in the >>> scheduler. The sysctl(8) variable "hw.blockcpu" takes a sequence of 4 >>> letters: S (for SMT), P (regular performance CPU), E (efficient CPU, >>> generally 80% to 50% as fast), and L (lethargic CPU) which are even slower. >>> Set this to select CPUs to kick out of the scheduler (SL by default). >>> Currently works on amd64 and arm64." >>> >>> Actually I'm running hw.blockcpu=E, and I see 4 cpus, in "L" I see 12...So, >>> as I said, I still don't quite understand the logic about it, can someone >>> be so kind to explain that for me? >>> >>> In "E" conf, my laptop runs smoothly, VMD and all, in "L" the same... :( >>> >>> Thanks in advance >>> >>> >>> -- >>> >>> Ronny Machado C. >>> >>> >>> IT Consultant >>> HP-UX Certified Systems Administrator >>> Oracle Linux Certified Implementation Specialist >>> Oracle MySQL Enterprise Certified Implementation Specialist >>> >>> https://sysops.cl >>> +56 9 7519 9262 >>> >>> Sent with Proton Mail secure email. >>> >> > <dmesg.txt>
