Win10电源模式拉条“最佳性能”与“最长续航”究竟有多大区别？
如题。点击win10系统工具栏右侧的电池图标，可以左右拉动拉条，选择三种电源模式：最佳性能、更好的性能、最强续航。T490 i7-8565U，打开AIDA64，在电脑静默、无大型程序正在运行的情形下，双手离开鼠标停止操作，观察CPU核心频率。
拉至最右侧“最佳性能”时，CPU核心频率始终在4.1GHz附近，最低3.6GHz，最高4.6GHz。
https://www.ibmnb.com/forum.php?mod=image&aid=2877160&size=300x300&key=b6fea0b9c50a3570&nocache=yes&type=fixnone
https://www.ibmnb.com/forum.php?mod=image&aid=2877159&size=300x300&key=971ec23b093b7135&nocache=yes&type=fixnone
拉至中间“更好的性能”时，CPU核心频率在0.9GHz至4.1GHz之间跳动，CPU请求电压下降至0.7V附近。
https://www.ibmnb.com/forum.php?mod=image&aid=2877165&size=300x300&key=3b057bddb224129b&nocache=yes&type=fixnone
https://www.ibmnb.com/forum.php?mod=image&aid=2877164&size=300x300&key=9ad9b71cc725fc48&nocache=yes&type=fixnone
拉至最左侧“最长续航”时，CPU核心频率绝大多数时间稳定在0.9GHz附近，CPU请求电压在0.62V-0.65V之间稳定。
https://www.ibmnb.com/forum.php?mod=image&aid=2877166&size=300x300&key=4c7e28f5d53a65f0&nocache=yes&type=fixnone
https://www.ibmnb.com/forum.php?mod=image&aid=2877167&size=300x300&key=19991d7fccdd858d&nocache=yes&type=fixnone
这里有一个问题请教大家：
这个电源模式管理是否可以仅仅看作是待机时更节能的选项？
当计算机运行软件、观看视频、跑程序时，这三种“电源模式”没有可见的差别。
网上与此相关的评测不多，且结果大多表明win10三种电源模式在高负载、单双烤鸡下没有明显的差异。
本帖最后由 stopyan 于 2019-11-6 14:56 编辑
Сtu~ 发表于 2019-11-6 13:26
如题。点击win10系统工具栏右侧的电池图标，可以左右拉动拉条，选择三种电源模式：最佳性能、更好的性能、 ...
楼主T490这代U，通常是通过更改Speed Shift 实现不同强度的频率调度。同时这个滑块有可能与DPTF挂钩，每档的功率墙 和 温度墙都可能随之不同。
T440P那代也会有类似的频率调度，不过温度墙和功率墙不受滑块影响。
就是三种散热设计而已。
分了三档。
顺便补充一下，19年所有TP机型统一都把这三种散热设计整合到了Win10这三种电源模式里，从左到右分别对应 最低功耗（散热最保守）、功耗平衡（散热性能中等）、最大功耗（散热最开放）
以我自己手里用的19款X1 Carbon为例，平衡模式下，满载在15W功耗左右；最高性能模式下，满载在23~25W之间；最低性能模式下，满载在10W功耗左右。 还是我来说吧，我常用更好性能与最佳性能，平时使用最选择更好性能即可，但是偶尔会有卡顿。如果选最佳性能，CPU一直维持高主频（4G以上）运行，性能确实好不少，也更流畅，但是电脑温度将会比较高。如果选最佳续航，那性能就要大打折扣，虽然不至于明显影响运行，但打开文件什么的是要慢那么一些，更别提处理图形什么就更慢了。thinkpad P52有时候会锁频0.9GHZ，那性能开机都要半分钟，上个网都卡。 帮顶 帮顶 帮顶 你应该试下用电池，不接电源。 BDbd帮顶 用电池差距还是有的。 stopyan 发表于 2019-11-6 14:54
楼主T490这代U，通常是通过更改Speed Shift 实现不同强度的频率调度。同时这个滑块有可能与DPTF挂钩，每 ...
感谢您的回复 我在贴吧曾看到过一种说法，调节滑块位置可以改变处理器和显卡的TDP和功耗墙，从而改善使用thinkpad玩常用游戏过程中严重掉帧和CPU锁频。
看来这是intel最近几年的一种新技术，我搜索了一下intel Speed Shift，结果喜人。看来这就是本疑问的正确答案——改变静默状态下的默认工作频率与电压，提高cpu时钟频率与计算机运行性能切换速度。
有空试一下使用电池时的区别。
找到了一篇英文的详细介绍文章，说的非常全面。我搬运过来。
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Modern computer processors are constantlychanging their operating frequency (and voltage) depending on workload. ForIntel processors, this is often handled by the operating system which willrequest a particular level of performance, known as the Performance State orP-State, from the processor. The processor then adjusts its frequencies andvoltage levels to accomodate, in a DVFS (dynamic voltage and frequency scaling)sort of way, but only at the P-states fixed at the time of production. Whilethe best for performance would be to run the system at the maximum all thetime, due to the high voltage, this is the least efficient way to run aprocessor and wasteful in terms of energy used, which for mobile devices meansa shorter battery life or thermal throttling. With the P-state model, toincrease efficiency, the operating system can request lower P-states in orderto save power, but if a task requires more performance, and the power/thermalbudgets are sufficient, the P-State can be changed to accomodate. This'technology' on Intel processors has historically been called 'Speed Step'.
With Skylake, Intel's newest 6th generationCore processors, this changes. The processor has been designed in a way thatwith the right commands, the OS can hand control of the frequency and voltageback to the processor. Intel is calling this technology 'Speed Shift'. We’vediscussed Speed Shift before in Ian’s Skylake architecture analysis, butdespite the in-depth talk from Intel, Speed Shift was noticably absent at thetime of the launch of the processors. This is due to one of the requirementsfor Speed Shift - it requires operating system support to be able to hand overcontrol of the processor performance to the CPU, and Intel had to work withMicrosoft in order to get this functionality enabled in Windows 10. As of rightnow, anyone with a Skylake processor is actually not getting the benefit of thetechnology, at least right now. A patch will be rolled out in November forWindows 10 which will enable this functionality, but it is worth noting that itwill take a while for it to roll out to new Windows 10 purchases.
Compared to Speed Step / P-statetransitions, Intel's new Speed Shift terminology, changes the game by havingthe operating system relinquish some or all control of the P-States, andhanding that control off to the processor. This has a couple of noticablebenefits. First, it is much faster for the processor to control the ramp up anddown in frequency, compared to OS control. Second, the processor has much finercontrol over its states, allowing it to choose the most optimum performance levelfor a given task, and therefore using less energy as a result. Specific jumpsin frequency are reduced to around 1ms with Speed Shift's CPU control from20-30 ms on OS control, and going from an efficient power state to maximumperformance can be done in around 35 ms, compared to around 100 ms with thelegacy implementation. As seen in the images below, neither technology can jumpfrom low to high instantly, because to maintain data coherency throughfrequency/voltage changes there is an element of gradient as data is realigned.
The ability to quickly ramp up performanceis done to increase overall responsiveness of the system, rather than linger atlower frequencies waiting for OS to pass commands through a translation layer.Speed Shift cannot increase absolute maximum performance, but on shortworkloads that require a brief burst of performance, it can make a bigdifference in how quickly that task gets done. Ultimately, much of what we dofalls more into this category, such as web browsing or office work. As anexample, web browsing is all about getting the page loaded quickly, and thengetting the processor back down to idle.
For this short piece, Intel was able toprovide us with the Windows 10 patch for Speed Shift ahead of time, so that wecould test and see what kind of gains it can achieve. This gives us a somewhatunique situation, since we can isolate this one variable on a new processor andmeasure its impact on various workloads.
To test Speed Shift, I’ve chosen severaltasks which have workloads that could show some gain from Speed Shift. Testswhich run the processor at its maximum frequency for long periods of time arenot going to show any significant gain, since you are not limited by theresponsiveness of the processor in those cases. The first test is PCMark 8,which is a benchmark which attempts to represent real-life tasks, and theworkload is not constant. In addition, I’ve run the system through severalJavascript tests, which are the best case scenario for something like SpeedShift, since the processor has to quickly complete a task in order to allow youto enjoy a website.
PCMark 8
The processor in question is an Intel Corei7-6600U, with a base frequency of 2.6 GHz, and turbo frequency of 3.4 GHz.Despite the base frequency being rated on the box at 2.6 GHz, the processor cango all the way down to 400 Mhz when idle, so being able to ramp up quicklycould make a big impact even on the U-series Skylake processors. My guess isthat it will be even more beneficial to the Y series Core m3/m5/m7 parts sincethey have a larger dynamic range, and typically more thermal constraints.
Both the Home and Work tests show a verysmall gain with Speed Shift enabled. The length of these benchmarks, which arebetween 30 and 50 minutes, would likely mask any gains on short workloads. Ithink this illustrates that Speed Shift is just one more tool, and not a holy grailfor performance. The gain on Home is just under 3%, and the difference on theWork test is negligible.
JavaScript Tests
JavaScript is one of the use cases whereshort burst workloads are the name of the game, and here Speed Shift has a muchbigger impact. All tests were done with the Microsoft Edge browser.
The time to complete the Kraken 1.1 test isthe least affected, with just a 2.6% performance gain, but Octane's scoresshows over a 4% increase. The big win here though is WebXPRT. WebXPRT includessubtests, and in particular the Photo Enhancement subtest can see up to a 50%improvement in performance. This bumps the scores up significantly, withWebXPRT 2015 showing an almost 20% score increase, and WebXPRT 2013 has a 26%gain. These leaps in performance are certainly the kind that would benoticeable to the end user manipulating photographs in something like Picasa orwatching web-page based graph adjustments such as live stock feeds.
Power Consumption
The other side of the coin is powerconsumption. Having a processor that can quickly ramp up to its maximum frequencycould mean that it will consume more power due to the greater penalty ofincreasing the voltage, but if it can complete the task quickly and get back toidle again, there is a chance to be more efficient when work is done in 10s ofmilliseconds rather than 100s of milliseconds, as the frequency ramps up anddown again before the old P-state method has decided to do anything. Theprinciple of 'work fast, finish now' was the backbone of Intel's 'Race ToSleep' strategy during the ultrabook era and focused on the impulse ofresponse-related performance, however the drive for battery life means thatefficiency has tended to matter more, especially as devices and batteries getsmaller.
Due to the way modern processors work, wedon’t have the tools to directly measure the SoC power. Intel has told us thatSpeed Shift does not impact battery life very much, one way or the other, so toverify this, I've run our light battery life test with the option disabled andenabled.
This task is likely one of the best case scenariosfor Speed Shift. It consists of launching four web pages per minute, withplenty of idle time in between. Although Speed Shift seems to have a slightedge, it is very small and would fall within the margin of error on this test.Some tasks may see a slight improvement in efficiency, and others may see aslight regression, but Speed Shift is less of a power savings tool than otherpieces of Skylake. Looking at it another way, if, for example, the XPS 13 withSkylake was to get 15 hours of battery life, Speed Shift would only change theresult by about 7 minutes. Responsiveness increases, but net power use remainsabout the same.
Final Words
With Skylake, while there was not the largeleap in clock for clock performance gain that we have become accustomed to withnew Intel microarchitectures, but when you look at the overall package, therewas a decent net gain in performance combined with new technologies. Forexample, being able to maintain higher Turbo frequencies on multiple cores hasincreased the stock to stock performance more than the smaller IPC gains.
Speed Shift is just one small part of theoverall performance gain, and one that we have not been able to look at untilnow. It does lead to some pretty big gains in task completion, if the workloadsare bursty and short enough for it to make a difference. It can’t increase theabsolute performance of the processor, but it can get it to maximum performancein a much shorter amount of time, as well as get it back down to idle quicker.Intel is billing it as improved responsiveness, and it’s pretty clear that theyhave achieved that.
The one missing link is operating systemsupport. We’ve been told that the patch to enable this is coming to Windows 10in November. While this short piece looks at what Speed Shift can bring to thetable in terms of performance, if you'd like to read more about how it isimplemented, please check out the Skylake architecture analysis which goes intomore detail.
正常使用更好性能就行，自动根据需求调整的，除非特殊需要长时间无法充电场合 看不懂那么多英文 帮顶 也不翻译一下 真的没认真比较过 没认真比较过 moto2287 发表于 2019-11-6 16:33
看不懂那么多英文
太长了！等有时间我翻译一下，分享到论坛上 学习到不少
顶顶帖子 傲雪吟霜 发表于 2019-11-7 00:25
就是三种散热设计而已。
分了三档。
顺便补充一下，19年所有TP机型统一都把这三种散热设计整合到了Win10 ...
谢谢！学习了 也没特别留意过这个，我总觉得这个只是显示屏亮度调一下{:1_243:} 傲雪吟霜 发表于 2019-11-7 00:25
就是三种散热设计而已。
分了三档。
顺便补充一下，19年所有TP机型统一都把这三种散热设计整合到了Win10 ...
是否可以理解为，其实对待机的功耗影响也不大？就是影响散热方案是激进还是保守、以及有负载时的功耗墙？ 学习到不少 结论就是区别不大呗？ 其实差距并没那么明显 帮顶 帮顶 支持这样的帖子，有数据，有理论，很好，对于使用电池的时候平衡性能和续航很有帮助。 顶顶顶
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