我最近的一个难题是：如果我加密我的计算机，计算性能会因此受到多大影响？会有很大的不同吗？如果有，在哪些地区？这就是为什么我决定在我的两台计算机上运行一些测试并了解更多关于TrueCrypt加密对计算性能的影响的原因。
正在测试的系统
测试是在两台计算机上进行的：台式机和笔记本电脑。台式机配置如下：AMD Phenom II X4 905（2.5 GHz）处理器，技嘉GA-MA785GT-UD3H主板(Gigabyte GA-MA785GT-UD3H motherboard)，内存为Corsair XMS3 DHX 6GB DDR3 1600 MHz，技嘉Radeon HD6870 OC 1GB (Gigabyte Radeon HD6870 OC 1GB) DDR5(DDR5 video)显卡和120GB RunCore Pro V 2.5" SATA III SSD 驱动器(SATA III SSD drive)。
与台式机不同，笔记本电脑没有SSD。它配备了以下组件：Intel Core2 Quad CPU Q9000 @ 2.00 GHz、6 GB RAM DDR2、ATI Mobility Radeon HD 4650和混合硬盘(HDD)- Seagate Momentus XT 500GB。
这两个系统都没有干净的Windows 安装(Windows installation)。它们已经使用了好几个月，并且拥有我通常在它们上面运行的所有软件。这是因为我想了解加密(performance impact encryption)对长期使用的系统的性能影响。
所做的测试
首先，在使用TrueCrypt(TrueCrypt)执行加密之前，我测量了每个系统的性能。
我用最新版本的Soluto(Soluto)测量了启动时间。然后，我使用 64 位版本的PCMark Vantage测量了一般计算性能，使用(PCMark Vantage)3DMark Vantage Advanced测量了图形和游戏性能。
PCMark Vantage分数是衡量计算机在各种常见计算任务（例如查看和编辑照片、视频、音乐和其他媒体、游戏、通信、生产力和安全性(productivity and security)）中的性能。您可以从此页面了解有关它执行的测试的更多信息：PCMark Vantage 功能(PCMark Vantage features)。
3DMark Vantage评估图形性能并运行两项图形测试、两项CPU测试和六项功能测试。如果您想了解高级(Advanced)版运行的测试，请查看此页面：Windows 上 DirectX 10 的视频卡基准测试(Video Card Benchmark for DirectX 10 on Windows)。
每个测试运行 3 次，我记录了所有 3 次运行的平均值。
然后，系统驱动器被(system drive)TrueCrypt完全加密，同样的测试又运行了 3 次。记录每次测试的平均分数。
加密如何影响启动时间(Does Encryption Impact Boot Timings)？
我的第一个问题是关于对启动时间的影响。我惊喜地发现影响很小。在带有混合硬盘的笔记本电脑上，启动速度仅慢了 5%（5 秒）。如果你问我，这是一个令人惊讶的好结果。
在配备SSD的台式机上，对启动时间没有影响。SSD做得很好，系统启动速度和以前一样快。
这是另一个证明，投资SSD可以提供非常好的性能。
加密(Encryption)对一般计算(General Computing Performance)性能的影响(Impact)
PCMark Vantage进行了多项测试，其平均分数是 7 个测试领域的平均分数：记忆（处理照片）、电视和电影(TV and Movies)、游戏(Gaming)、音乐(Music)、通信(Communications)、生产力和硬盘(Productivity and HDD)。分数受加密的影响很大。
在笔记本电脑上，整体性能% decrease，而在台式机上，性能% decrease
我查看了各个结果，看起来两个系统在HDD测试中都感受到了最大的影响。在那里，尤其是SSD受到了很大的冲击，性能降低了 20%。
在涉及大量数据写入硬盘的所有测试中，性能差异很大。在某些测试中，SSD的写入速度降低了 30%。但是，笔记本电脑的混合硬盘受到的打击要少得多。它的写入速度有所下降，但从未低于 10%。
我注意到的另一个特殊结果是PCMark Vantage报告的游戏性能几乎没有受到加密的影响——% decrease。
加密(Encryption)对游戏性能(Gaming Performance)的影响(Impact)
3DMark Vantage Advanced基准测试证实了(3DMark Vantage Advanced)PCMark Vantage分享的关于游戏性能的结论。
在笔记本电脑和台式机上的所有测试中都没有影响。性能下降(performance decrease)小于 0.1% 。它是如此之小以至于不引人注目。
我预计影响很小，因为游戏在向硬盘写入数据方面并不涉及硬盘。游戏主要是关于读取数据、对处理器、显卡(video card)和RAM 内存(RAM memory)施加压力。因此，您的系统是否加密并不重要。它的工作原理相同。
结论
我的测试揭示了有趣的结果。使用TrueCrypt(TrueCrypt)加密您的计算机似乎会对您的系统性能产生合理的影响。使用传统硬盘时，启动时间会略有增加，而使用SSD(SSDs)时没有影响。游戏性能完全不受影响，而一般计算任务会受到影响，尤其是当您必须将数据写入硬盘时。不过奇怪的是，在使用加密时，传统硬盘的影响似乎比SSD小。(SSDs)但是，即使您的系统已加密，拥有SSD仍将提供比传统硬盘更好的性能。
What is the Performance Impact of System Encryption With TrueCrypt
One of my recent dilemmas was: if I encrypt my computer, how much will computing performance have to suffer because of it? Will thеre be a big difference? If yes, in which areas? That's why I decided to run some teѕts on both my computers and learn more about the imрact TrueCrypt encryption has on computing performance.
Systems Being Tested
The tests were made on two computers: a desktop and a laptop. The desktop has the following configuration: AMD Phenom II X4 905 (2.5 GHz) processor, a Gigabyte GA-MA785GT-UD3H motherboard, the memory is Corsair XMS3 DHX 6GB DDR3 1600 MHz, a Gigabyte Radeon HD6870 OC 1GB DDR5 video card and a 120GB RunCore Pro V 2.5" SATA III SSD drive.
Unlike the desktop, the laptop doesn't have an SSD. It is equipped with the following components: Intel Core2 Quad CPU Q9000 @ 2.00 GHz, 6 GB of RAM DDR2, ATI Mobility Radeon HD 4650 and a hybrid HDD - Seagate Momentus XT 500GB.
Neither of the systems has a clean Windows installation. They were used for many months and have all the software I usually run on them. This is because I wanted to learn the performance impact encryption will have on systems that are used on a daily basis for a long period of time.
The Tests That Were Made
First, I measured the performance on each system, prior to performing the encryption with TrueCrypt.
I measured the boot timings with the latest version of Soluto. Then, I measured general computing performance using the 64-bit version of PCMark Vantage and graphics and gaming performance using 3DMark Vantage Advanced.
A PCMark Vantage score is a measure of the computer's performance across a variety of common computing tasks such as viewing and editing photos, video, music and other media, gaming, communications, productivity and security. You can learn more about the tests it performs from this page: PCMark Vantage features.
3DMark Vantage evaluates graphics performance and it runs two graphics tests, two CPU tests and six feature tests. If you want to learn about the tests run by the Advanced edition, check out this page: Video Card Benchmark for DirectX 10 on Windows.
Each test was run three times and I recorded the average of all three runs.
Then, the system drive was fully encrypted with TrueCrypt and the same tests were run again, three times. The average scores were recorded for each test.
How Does Encryption Impact Boot Timings?
My first question was about the impact on boot timings. I was pleasantly surprised to notice that the impact was minimal. On the laptop with the hybrid hard drive, the boot was only 5% (5 seconds) slower. A surprisingly good result if you ask me.
On the desktop, which is equipped with an SSD, there was no impact on boot timings. The SSD did its job very well and the system booted just as fast as before.
This is another proof that investing in an SSD delivers really good performance.
The Impact of the Encryption on General Computing Performance
PCMark Vantage runs several tests and its average score is an average of 7 testing areas: Memories (working with photos), TV and Movies, Gaming, Music, Communications, Productivity and HDD. The scores were highly impacted by encryption.
On the laptop an overall 4% decrease was noticed while on the desktop a huge 15% decrease in performance was noticed.
I looked at the individual results, and it looks like the biggest impact is felt by both systems in the HDD tests. There, especially the SSD is hit a lot, delivering 20% less performance.
In all the tests where a lot of data writing on the hard disk was involved, the difference in performance was huge. The SSD had its writing speed lowered by 30% in some tests. However, the hybrid hard disk from the laptop was hit a lot less. It had a decrease in writing speed but never lower than 10%.
Another peculiar result I noticed is that gaming performance as reported by PCMark Vantage, was hit very little by encryption - around 5% decrease.
The Impact of the Encryption on Gaming Performance
The 3DMark Vantage Advanced benchmark confirmed the conclusions about gaming performance, that were shared by PCMark Vantage.
There was no impact in all tests, both on the laptop and the desktop. The performance decrease was less than 0.1%. It was so small that it wasn't noticeable.
I expected very little impact due to the fact that gaming doesn't involve the hard disk much in terms of writing data to it. Gaming is mostly about reading data, stressing the processor, the video card and your RAM memory. Therefore, it doesn't matter if your system is encrypted or not. It works the same.
Conclusion
My tests revealed interesting results. It seems that encrypting your computer with TrueCrypt will have a reasonable impact on the performance of your system. The boot timings will see a small increase when using traditional hard disks and no impact when using SSDs. Gaming performance is not impacted at all, while general computing tasks will suffer, especially when you have to write data to the hard disk. What's strange though is that traditional hard disks seem to be impacted less than SSDs when using encryption. However, having an SSD will still deliver better performance than a traditional hard disk, even when your system is encrypted.
