It's kinda mesmerizing watching the core speeds on one of the i7-12700Ts in the #Proxmox Cluster (the one that runs Tiggi.es presently) dynamically shift cores anywhere from 1400Mhz to 4.62GHz quickly, and on an as-needed basis. The low base speed saves energy, but it'll instantly pop cores up to speeds within its thermal/power limit envelope, so for lightly-threaded workloads, it can perform as well as beefier chips. #homelab#servers#cpu
@stooovie BIOS settings can override this as well. Lots of consumer motherboards specifically ignore Intel's power management/limits if you select their "optimized" or "auto" modes for clock speeds/voltage, etc. These are HP Workstations that don't have those options, though you can bypass some of them/change them at runtime by using powercap-utils.
@LeoBurr yeah, not on my mini pc though, it was just the governor set to Performance by default on a clean Proxmox 7 install. Setting it to On Demand (I think?) lowered the power draw to a Raspberry Pi 4 levels with no obvious issues (running Nextcloud, Home Assistant, Jellyfin... The typical home lab stuff).
As far as I know Proxmox uses performance by default, which makes for a machine with high utilisation but it’s less ideal for a machine that’s idle most of the time
@mario@stooovie I've looked at this setting and have tried changing it.
On Comet Lake and later, I'm seeing powersave disabling turbo boost and limiting cores to the base frequency while allowing cores to go even lower than base frequency before returning to it. Performance mode runs the cores at base frequency and permits them to turbo boost before returning to base frequency.
Given this behavior, and the low power nature of these systems (and the fact I've got solar panels generating an average of 50-60kW daily), I'll be leaving the systems on Performance Mode.
If I wanted to control turbo boosting, I'd just use powercap-utils and set the short-term power limit down, so the CPU uses less power when demand is there, but this will also impact performance negatively in high utilization bursty scenarios.
Instead of doing that, since I value performance over saving a few watts, I'm going to set my long-term power limits (thus TDP) up from 65w to 85w as the CPU cooler can handle it based on XTU testing, and short term will actually be lowered from 135w to 125w, but the window extended to ~57 seconds to enable larger workloads to complete more rapidly.
I can see Powersave making sense where Proxmox is being used locally with sipping power taking precedence over performance...but I bought these CPUs to perform, so I'm gonna help them do just that. ;)
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