In OpenBSD you can let the kernel do the power management with "sysctl hw.perfpolicy=auto". Also there was fix in ACPI in 5.8 to fix power use in newer process

In OpenBSD you can let the kernel do the power management with "sysctl hw.perfpolicy=auto". Also there was fix in ACPI in 5.8 to fix power use in newer processors. If I remember it correctly the processor didn't use the deep sleep states so they consumed more power.