I too approve of the memory bling, DIMM shady.
Announcement
Collapse
No announcement yet.
Noctua NH-U9S Performance For The AMD Ryzen 9 3950X + Ondemand vs. Performance Governors
Collapse
X
-
Originally posted by GreenReaper View PostI don't think the ondemand governor is going to be optimal for a benchmark usage pattern, which naturally has a higher level of usage than usual.
That said, I've always preferred use of the performance governor and I think especially on modern CPUs it works out well because it delegates the decision to the processor, essentially just setting a performance bias. The CPU is probably in the best position to make the fast decisions about how to use power most effectively.
Edit: Isn't the feral gamemode daemon supposed to manage this in a better way? i.e. automatically switching to performance governor when you start playing a game, and then switching back to ondemand after you're finished.Last edited by torsionbar28; 11 February 2020, 01:07 PM.
Comment
-
Originally posted by GreenReaper View PostI don't think the ondemand governor is going to be optimal for a benchmark usage pattern, which naturally has a higher level of usage than usual.
That said, I've always preferred use of the performance governor and I think especially on modern CPUs it works out well because it delegates the decision to the processor, essentially just setting a performance bias. The CPU is probably in the best position to make the fast decisions about how to use power most effectively.
Here's a hint:
They don't want the CPU to have the final word in the decision-making queue, since the Linux kernel has way more knowledge about what is currently happening than the dumb firmware/microcode inside the CPU!
An analogy can be seen in NVMe-SSDs:
Why do You think Facebook developed the >>Kyber<< IO-scheduler, when they could have delegated the decision-making to the embedded micro-controller on those drives, since, You know, they are smart enough already?
Exactly! It's all about giving the Linux kernel control over the whole hardware-stack, from top-to-bottom!
Comment
-
Originally posted by atomsymbol
According to my measurements, ondemand saves about 10 Watts on desktop Ryzen at the outlet when performing light tasks such as playing a Youtube video.
But tasks tend to run 5% slower with ondemand governor compared to performance, so the performance governor returns to idle sooner than ondemand when the task completes.
In CPU-intensive scenarios, ondemand (by definition) saves no power.
The turbostat tool can be used to measure power consumption from a Linux terminal ("linux-tools" package in Ubuntu), although it isn't exactly the same as measuring power at the outlet.
Code:sudo cpupower frequency-set -g performance
Code:~ % head /proc/cpuinfo processor : 0 vendor_id : AuthenticAMD cpu family : 23 model : 8 model name : AMD Ryzen 7 2700X Eight-Core Processor stepping : 2 microcode : 0x800820d cpu MHz : 3504.598 cache size : 512 KB physical id : 0 ~ % LC_ALL=C sudo cpupower frequency-info analyzing CPU 0: no or unknown cpufreq driver is active on this CPU CPUs which run at the same hardware frequency: Not Available CPUs which need to have their frequency coordinated by software: Not Available maximum transition latency: Cannot determine or is not supported. Not Available available cpufreq governors: Not Available Unable to determine current policy current CPU frequency: Unable to call hardware current CPU frequency: Unable to call to kernel boost state support: Supported: yes Active: yes Boost States: 0 Total States: 3 Pstate-P0: 3700MHz Pstate-P1: 3200MHz Pstate-P2: 2200MHz ~ % LC_ALL=C sudo cpupower frequency-set -g performance Setting cpu: 0 Error setting new values. Common errors: - Do you have proper administration rights? (super-user?) - Is the governor you requested available and modprobed? - Trying to set an invalid policy? - Trying to set a specific frequency, but userspace governor is not available, for example because of hardware which cannot be set to a specific frequency or because the userspace governor isn't loaded?
Comment
-
Originally posted by atomsymbol
Are you sure you have frequency scaling enabled in BIOS and in kernel config?
Code:% zgrep -i freq /proc/config.gz CONFIG_ACPI_CPU_FREQ_PSS=y # CPU Frequency scaling CONFIG_CPU_FREQ=y CONFIG_CPU_FREQ_GOV_ATTR_SET=y CONFIG_CPU_FREQ_GOV_COMMON=y CONFIG_CPU_FREQ_STAT=y # CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set # CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE is not set # CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set # CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND is not set # CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE is not set CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL=y CONFIG_CPU_FREQ_GOV_PERFORMANCE=y CONFIG_CPU_FREQ_GOV_POWERSAVE=m CONFIG_CPU_FREQ_GOV_USERSPACE=m CONFIG_CPU_FREQ_GOV_ONDEMAND=m CONFIG_CPU_FREQ_GOV_CONSERVATIVE=m CONFIG_CPU_FREQ_GOV_SCHEDUTIL=y # CPU frequency scaling drivers CONFIG_CPUFREQ_DT=m CONFIG_CPUFREQ_DT_PLATDEV=y CONFIG_X86_PCC_CPUFREQ=m CONFIG_X86_ACPI_CPUFREQ=m CONFIG_X86_ACPI_CPUFREQ_CPB=y CONFIG_X86_AMD_FREQ_SENSITIVITY=m # end of CPU Frequency scaling CONFIG_DEVFREQ_THERMAL=y CONFIG_PM_DEVFREQ=y # DEVFREQ Governors CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND=m CONFIG_DEVFREQ_GOV_PERFORMANCE=m CONFIG_DEVFREQ_GOV_POWERSAVE=m CONFIG_DEVFREQ_GOV_USERSPACE=m CONFIG_DEVFREQ_GOV_PASSIVE=m # DEVFREQ Drivers CONFIG_PM_DEVFREQ_EVENT=y # Frequency Synthesizers DDS/PLL # Phase-Locked Loop (PLL) frequency synthesizers # end of Phase-Locked Loop (PLL) frequency synthesizers # end of Frequency Synthesizers DDS/PLL
Comment
Comment