5 ms·
If you're using Intel 8th gen or above. (7th gen supported if you manually set the flag each boot) you've got speedshift which the CPU will automatically auto s
by tamrix 5y ago
If you're using Intel 8th gen or above. (7th gen supported if you manually set the flag each boot) you've got speedshift which the CPU will automatically auto scale itself. (changing the p-states)
The CPU itself can change frequencies much faster on its own instead of the software based speedstep which programs like this controlled.
This eliminates the need for an on-battery or plugged-in performance mode because it changes frequencies so fast, you're no longer losing performance by waiting for the software to speed up the cpu. So you can keep it on all the time.
For these CPUs, all this is in the kernel and enabled by default.
- nceqs3 5y agoI believe that feature was just litigated in VLSI v Intel. VLSI won 2.1 billion in damages due to their patent.
- wyager 5y agoThe patent system is so useful, charging vendors billions of dollars for implementing an idea like “use the most obvious possible power saving strategies”.
- orangepurple 5y agoThe patent system also helps small companies with little working capital get started on big, obvious, money intensive challenges without being immediately crushed by megacorps. The razor cuts both ways.
- nceqs3 5y agoYes, this is the truth. Look at the recent Cisco patent case. They pulled a Facebook and stole some startups IP while meeting with them. The startup won over 1.5 billion in damages, mostly because they were able to show willful infringement on Cisco's part. https://www.ipwatchdog.com/2020/10/09/centripetal-networks-awarded-1-9-billion-infringement-suit-cisco/id=126094/ https://www.ipwatchdog.com/2020/10/09/centripetal-networks-a...
- Roritharr 5y agoIs the same true for Ryzen CPUs?
- Zenst 5y agoI had a look and https://www.tomshardware.com/uk/reviews/amd-ryzen-9_3900x-vs-intel-core_i7-9900k,6225.html https://www.tomshardware.com/uk/reviews/amd-ryzen-9_3900x-vs... "AMD’s Ryzen 9 3900X also has the new Collaborative Power Performance Control 2 (CPPC2) feature, which manipulates Ryzen 3000's power states from within the operating system. This is similar to Intel's Speed Shift technology and reduces power state transition latency. Ultimately, that results in a more efficient processor during all facets of operation." Though that seems to be about boosting clocks higher clocks when it can. https://www.amd.com/en/technologies/smartshift https://www.amd.com/en/technologies/smartshift Again does seem to focus upon boosting performance So no clear-cut stand-out answer, but does seem some level of OS interaction is required, I couldn't say with 100% certainty.
- lrem 5y agoWhy does Windows do on-battery/plugged-in performance modes on Microsoft hardware with 10th gen i7?
- cute_boi 5y agomost of it is brightness related thing and i understand there are various inner settings but I find them doing very little. So it usually doesn't bring value to the table.
- fho 5y agoIn theory it could inform programs like messengers to behave battery friendly. In practice I don't think that is implemented.
- vbezhenar 5y ago> This eliminates the need for an on-battery or plugged-in performance mode because it changes frequencies so fast, you're no longer losing performance by waiting for the software to speed up the cpu. So you can keep it on all the time. Here's my /etc/rc.d/rc.local script: #!/bin/sh for policy in /sys/devices/system/cpu/cpufreq/policy* do echo "power" > "$policy"/energy_performance_preference done Here's available preferences: $ cat /sys/devices/system/cpu/cpufreq/policy0/energy_performance_available_preferences default performance balance_performance balance_power power Basically I can choose between "performance" and "power" (low performance) modes. I'm choosing power, so my fans are silent. And they're silent indeed, no matter the load.
- Hello71 5y agoecho power | tee /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
- alexeldeib 5y agofor no additional output, sponge over tee! sponge is useful in some cases where redirecting output is annoying, and it can construct pipelines reading/writing from the same file. Found that one way later than I'd care to admit. I use tee $FILE > /dev/null <EOF quite often in some situations where redirects get ugly, and sponge is a nice util to tidy up the invocation.
- avel 5y agoUseful, thank you. It appears that this is the setting the Ubuntu / Gnome's "Power -> Power mode" setting changes as well.
- ComputerGuru 5y agoFor reference, 7th gen is Kaby Lake and 8th gen is Coffee Lake. Of course, Intel had stagnated long before so many people are still on Sky Lake (6th gen).
- fomine3 5y agoSpeedShift is from Skylake so 6th, isn't it?, or is there any Linux specific limitation?