(I had to look that up.) Yeah, they're different. Speedstep is est(4), the ~15-year old predecessor to Speedshift. They serve similar purposes but purportedly (and plausibly) Speedshift does a better job; also SpeedStep is maybe going away entirely in newer CPUs.
Current gens like Skylake and Kabylake have silicon for both, but if intel_hwpstate(4) is enabled, est(4) doesn't work; hence the kludge in est(4) to avoid "identifying" if intel_hwpstate(4) successfully identified (wasn't disabled && new enough CPU). Best, Conrad On Thu, Jan 23, 2020 at 12:55 AM Ravi Pokala <[email protected]> wrote: > > -----Original Message----- > From: <[email protected]> on behalf of Conrad Meyer > <[email protected]> > Date: 2020-01-22, Wednesday at 15:28 > To: <[email protected]>, <[email protected]>, > <[email protected]> > Subject: svn commit: r357002 - in head: share/man/man4 sys/conf sys/kern > sys/modules/cpufreq sys/sys sys/x86/cpufreq > > Author: cem > Date: Wed Jan 22 23:28:42 2020 > New Revision: 357002 > URL: https://svnweb.freebsd.org/changeset/base/357002 > > Log: > cpufreq(4): Add support for Intel Speed Shift > > Intel Speed Shift is Intel's technology to control frequency in > hardware, > with hints from software. > > Not to be confused with Intel Speed *Step*, right? > > (/me was confused; naming things is hard) > > -Ravi (rpokala@) > > Let's get a working version of this in the tree and we can refine it > from > here. > > Submitted by: bwidawsk, scottph > Reviewed by: bcr (manpages), myself > Discussed with: jhb, kib (earlier versions) > With feedback from: Greg V, gallatin, freebsdnewbie AT freenet.de > Relnotes: yes > Differential Revision: https://reviews.freebsd.org/D18028 > > > _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
