Date: Wed, 09 Oct 2019 16:07:30 +0000 From: Koakuma <koachan@protonmail.com> To: freebsd-ppc <freebsd-ppc@freebsd.org> Subject: CPU frequency scaling doesn't work on Mac mini G4 Message-ID: <BUAw5HidTMMt7nvgX089wTXfeyeHgDMapLSBDeeOylWdA31J2U5iVPCSLSSwZtRI1us9uwp5ZjBw1sB8G9pRqH7Jon3WvNK9aZI2MVPkcTo=@protonmail.com>
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Hi, I've just noticed a strange behavior regarding frequency scaling on the Mac mini G4. When I tried to set the CPU frequency using powerd, it (and "sysctl dev.cpu.0.freq") reports that the frequency has been changed, yet a test using "openssl speed" shows similar performance between the two frequencies. Here's the result of running "openssl speed -evp chacha20" with "powerd -n maximum" (1416 MHz): type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes 16384 bytes chacha20 40326.69k 61947.78k 70339.29k 72921.32k 73479.72k 73307.48k And with "powerd -n minimum" (708 MHz): type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes 16384 bytes chacha20 40314.57k 62121.26k 70303.44k 72740.17k 73468.76k 73520.78k I expect that openssl would run slower when the CPU frequency is set to minimum, but that's not the case here. Is it a bug or did I use the wrong program to measure it? The system is a freshly-installed 12.0-RELEASE on the 1.4 GHz model.help
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