现代处理器有两种常用频率，或者如果您愿意，可以使用时钟，它们告诉我们它们的基本速度(base speed)和加速速度(boost speed)。为了能够即时调整它们的速度(speed on-the-fly)，处理器需要算法来告诉它们何时这样做。对于AMD的Ryzen处理器，这些算法称为Precision Boost。这是它们内置的功能，从理论上讲，它对它们的性能有重大影响。我们很想知道到底有多少，所以我们决定使用AMD Ryzen 7 3700X处理器，(processor and measure)并在开启和不开启Precision Boost的情况下测量其性能。这是我们发现的：
我们用于测量Precision Boost影响的 PC(Precision Boost)
Ryzen 7 3700X 是 2019 年最好的处理器之一。它有 8 个物理内核、16 个线程，以 3600 MHz 的基本速度运行，最高可(MHz)提升至 4.4 GHz。使用AMD(AMD)算法的Precision Boost功能可以在需要时提高CPU的频率，从而获得最大的提升速度。(boost speed)禁用Precision Boost意味着处理器无法再提升其频率，因此它永远不会以高于其基本时钟速度(base clock speed)3.6GHz 的频率运行。如果您想了解更多有关Precision Boost 的信息，(Precision Boost,)请阅读：什么是Turbo Boost 或 Precision Boost(Turbo Boost or Precision Boost)说到处理器？
为了查看为AMD Ryzen 7 3700X打开或关闭 Precision Boost 对性能的(Precision Boost)影响，我们运行了一些基准测试。(performance impact)这是我们测试它的计算机：
- 主板：华硕ROG Crosshair VIII Hero(ASUS ROG Crosshair VIII Hero)（Wi-Fi）
- 冷却器：ROG Ryou 120
- 内存：HyperX Predator DDR4 RGB 内存(HyperX Predator DDR4 RGB Memory)（2 x 8GB，3600MHz）
- 显卡：华硕 ROG STRIX (Card)GTX 1660 (ASUS ROG STRIX GTX 1660) Ti GAMING OC
- 存储：ADATA XPG Gammix S11 Pro SSD
- 显示器：华硕 ROG Strix XG32VQ( ASUS ROG Strix XG32VQ)曲面电竞显示器(Gaming Monitor)（32 英寸WQHD 2560 x(x 1440) 1440，144Hz）
- 电源(Power Supply Unit)：ASUS ROG Thor 850W Platinum
- 操作系统(Operating System)：Windows 10 Pro x64，2019年 5 月(May 2019) 更新(Update)
我们主板上的UEFI BIOS让我们可以在其Extreme Tweaker页面上轻松启用或禁用处理器的Precision Boost功能。(Precision Boost)
所有基准测试均在Windows 10 Pro版本 1903(version 1903)内部版本 18362.418 和可用的最新驱动程序上运行。
接下来，让我们看看我们在游戏和基准测试中的结果，同时在库存设置上运行我们的AMD Ryzen 7 3700X，启用Precision Boost，以及何时关闭它。
AMD Ryzen 处理器(AMD Ryzen processor)从 Precision Boost中受益多少？
我们首先运行CPU-Z(CPU-Z)提供的单线程基准测试。该基准测试最大程度地使用单核时处理器的性能。因此，当Precision Boost开启且处理器可提升至 4.4GHz 时， (Precision Boost)CPU的得分比关闭且(CPU)CPU以 3.6GHz 运行且没有提升时要好得多（高出 17.82%） 。
在CPU-Z的多线程基准测试中，我们看到了同样的情况。启用处理器的Precision Boost意味着显着的性能提升(performance improvement)，提升了 13.35%。
在渲染基准Cinebench R20中，当我们启用(Cinebench R20)Precision Boost时，我们的(Precision Boost)AMD Ryzen 7 3700X与禁用它时相比，性能提升(performance boost)了 11.40% 。
Blender测量处理器渲染两个不同场景所需的时间。时间越短，处理器越快。打开Precision Boost意味着我们的Ryzen 7 3700X 速度提高了 11.50%。
在PCMark 10中，评估处理器在日常计算任务中的表现，例如网页浏览(web browsing)、视频会议(video conferencing)、应用程序启动时间、生产力和数字内容创建(content creation)，开启Precision Boost意味着性能提升 10.79%。
7-Zip 的压缩测试(Compression test)告诉我们，启用Precision Boost后， (Precision Boost)AMD Ryzen 7 3700X 压缩文件的速度明显更快：准确地说是快了 30.76%。
在 7-Zip 的 Decompression 中，启用Precision Boost可使性能提高21.93 % increase。
在网页浏览(web browsing)基准JetStream 2中（我们在Google Chrome中运行它），Precision Boost功能带来了 18.40% 的速度提升。
在游戏方面，单核处理器性能(processor performance)是最受关注的。我们通过测试几款游戏来验证这是否属实：《古墓丽影(Tomb Raider)》、《地铁离去(Metro Exodus)》和《僵尸世界大战》(World War Z)。我们将它们配置为以 1920 x 1080像素分辨率和可用的最低图形细节运行，这样我们的显卡就不会成为AMD Ryzen 7 3700X 的瓶颈。
在《古墓丽影(Tomb Raider)之影(Shadow)》中，开启Precision Boost时(Precision Boost)CPU 渲染测量(CPU Render measurement)显示性能大幅提升 21.91% 。
在Metro Exodus中， (Metro Exodus)Precision Boost开启与关闭之间的差异要小一些，但仍然很显着：5.81%。
在 World War Z 中，与关闭处理器的Precision Boost功能运行游戏相比，设置(Precision Boost)Precision Boost意味着每秒增加 29 帧（增加 16.57%） 。
温度也受到Precision Boost功能状态的影响。启用时，最高温度为 89摄氏度(Celsius)。当我们关闭Precision Boost时，最高温度为 71摄氏度(Celsius)。由于Precision Boost被禁用，我们的Ryzen 7 3700X 没有将其频率提升到 4.4GHz，这意味着更低的温度。
关闭Precision Boost时，功耗(power consumption)也会下降。在我们的案例中，它从最大 90瓦(Watts)变为仅 69瓦(Watts)。
我们还记录了处理器在单核上达到的最大频率。启用Precision Boost后，锐龙7(Ryzen 7) 3700X 达到了 4392MHz 的高位，接近厂商宣称的 4400MHz。关闭Precision Boost(Precision Boost)显然意味着CPU无法再提升，因此它始终工作在 3593MHz 。
Precision Boost对(Boost)AMD 锐龙(AMD Ryzen)处理器的性能有显着的积极影响
这种比较已经证明，Precision Boost功能不是营销噱头(marketing gimmick)。如果您想在任何应用程序或游戏(app or game)中享受明显更好的性能，请确保启用Precision Boost。它应该默认打开，但无论哪种方式检查都没有坏处。您可以获得更好的性能，通常比禁用Precision Boost高 10% 到 20% 左右。(Precision Boost)但是处理器的温度和功耗增加(temperature and power consumption increase)了一点，但没有手动超频的弊端，如本实验所示：AMD(Does AMD)的PBO（Precision Boost Overdrive）和AutoOC（自动超频(Auto OverClocking)）提高性能(increase performance)？
您对AMD的Precision Boost 功能(Precision Boost feature)有何看法？
我们希望您发现我们的实验很有趣(experiment interesting)，我们鼓励您进行自己的分析和基准测试(analysis and benchmarks)。出发前，请告诉我们您使用Precision Boost和AMD Ryzen处理器的体验。您对他们必须提供的性能感到满意吗？在下面发表评论(Comment)，让我们讨论。
The performance impact of Precision Boost for AMD Ryzen processors
Modern processors come with two stock frequencies, or clocks if yоu prefer, which tell us their base spеed and theіr boost speed. To be аble to adjust their speed оn-the-fly, processors need algorithms that tell them when to do that. For AMD's Ryzen processors, thosе algorithms are called Precision Boost. It is a feature that's built into them and which, theoretically, has a significant effect on their performance. We were curious to see just how much, so we decided to use an AMD Ryzen 7 3700X processor and measure its performance with and without Precision Boost turned on. Here is what we found out:
The PC we used for measuring the impact of Precision Boost
The Ryzen 7 3700X is one of the best processors of 2019. It has eight physical cores, 16 threads, runs at a base speed of 3600 MHz, and can boost up to 4.4 GHz. The maximum boost speed is attainable using the Precision Boost feature that uses AMD's algorithms to increase the CPU's frequency when it needs it. Disabling Precision Boost means that the processor can no longer boost its frequency, so it is never running at a higher frequency than its base clock speed of 3.6GHz. If you'd like to know more about Precision Boost, read: What is Turbo Boost or Precision Boost when it comes to processors?.
To see the performance impact of turning Precision Boost on or off for the AMD Ryzen 7 3700X, we ran some benchmarks. Here is the computer on which we tested it:
The UEFI BIOS on our motherboard lets us easily enable or disable the Precision Boost feature of the processor on its Extreme Tweaker page.
All the benchmarks were run on Windows 10 Pro, version 1903, build 18362.418, and the latest drivers available.
Next, let's see what results we had in games and benchmarks, while running our AMD Ryzen 7 3700X on stock settings, with Precision Boost enabled, and when we turned it off.
How much does an AMD Ryzen processor benefit from Precision Boost?
We started by running the Single-Thread benchmark offered by CPU-Z. This benchmark tests the performance of the processor when using a single core to the max. As such, the score of the CPU when Precision Boost was on and the processor could boost up to 4.4GHz was much better (17.82% better) than when it was off and the CPU ran at 3.6GHz with no boost.
In CPU-Z's Multi-Thread benchmark, we saw the same thing. Enabling the processor's Precision Boost meant a significant performance improvement, increasing by 13.35%.
In Cinebench R20, which is a rendering benchmark, our AMD Ryzen 7 3700X had a performance boost of 11.40% when we enabled Precision Boost, compared to when we disabled it.
Blender measures the time required for the processor to render two different scenes. The shorter the time, the faster the processor. Turning Precision Boost on meant that our Ryzen 7 3700X was faster by 11.50%.
In PCMark 10, which evaluates the processor in daily computing tasks, such as web browsing, video conferencing, apps start-up times, productivity, and digital content creation, turning Precision Boost on meant an increase in performance of 10.79%.
7-Zip's Compression test told us that the AMD Ryzen 7 3700X is significantly faster at zipping files when Precision Boost is enabled: 30.76% faster to be precise.
In 7-Zip's Decompression, enabling Precision Boost resulted in a 21.93% increase in performance.
In JetStream 2, a benchmark for web browsing (we ran it in Google Chrome), the Precision Boost feature brought an improvement of 18.40% in speed.
Single-core processor performance is of the highest interest when it comes to games. We checked to see if that's true, by testing a few games: Shadow of the Tomb Raider, Metro Exodus, and World War Z. We configured them to run at 1920 x 1080 pixels resolution and with the lowest graphics details available so that our graphics card did not bottleneck the AMD Ryzen 7 3700X.
In Shadow of the Tomb Raider, the CPU Render measurement showed a major increase in performance of 21.91% when turning Precision Boost on.
In Metro Exodus, the discrepancy between running with Precision Boost on versus off was a bit smaller, but significant nonetheless: 5.81%.
In World War Z, setting Precision Boost on meant 29 more frames per second (an increase of 16.57%), compared to when running the game with the processor's Precision Boost feature turned off.
Temperatures were also affected by the state of the Precision Boost feature. When it was enabled, the maximum temperature was 89 degrees Celsius. When we turned Precision Boost off, the maximum temperature was 71 degrees Celsius. Because Precision Boost was disabled, our Ryzen 7 3700X did not boost its frequency to 4.4GHz, which meant lower temperatures.
The power consumption also drops when Precision Boost is turned off. In our case, it went from a maximum of 90 Watts to a mere 69 Watts.
We also logged the processor's maximum frequency achieved on a single core. When Precision Boost was enabled, the Ryzen 7 3700X reached a high of 4392MHz, which is close to the 4400MHz stated by the manufacturer. Turning Precision Boost off obviously meant that the CPU couldn't boost anymore, so it always worked at 3593MHz.
Precision Boost has a significant positive impact on the performance of AMD Ryzen processors
This comparison has proven that the Precision Boost feature is not a marketing gimmick. If you want to enjoy significantly better performance in any app or game, make sure that you enable Precision Boost. It should be on by default, but it doesn't hurt to check either way. You get better performance, usually around 10% to 20% more than with Precision Boost disabled. However, the processor's temperature and power consumption increase a bit, but without the downsides of doing manual overclocking, as shown in this experiment: Does AMD's PBO (Precision Boost Overdrive), and AutoOC (Auto OverClocking) increase performance?
What is your opinion about AMD's Precision Boost feature?
We hope that you found our experiment interesting, and we encourage you to make your own analysis and benchmarks. Before you go, tell us about your experience with Precision Boost and AMD Ryzen processors. Are you satisfied with the performance that they have to offer? Comment below and let's discuss.
