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Windows tweaking and optimization: myths and reality

Applies to: Windows 7

There are many sites that change Windows behavior or settings, some of which even disable services or functionality. It is interesting that almost none of these sites explain the real benefits of tweaking Windows. You may see assurances such as "the system seems to be much faster" or promises of a 10 to 20 percent performance gain. I've even seen a promise to make a Windows system up to 50 times faster!

However, it is difficult to find any measurable results. Few sites present actual results metrics, and when they do, the numbers primarily report decreased boot times. (I ignore the "fake" with changing Windows Hardware Abstraction Layer (HAL) during installation to 486C compatible.) While you may decrease the boot time there are not strong dependencies between boot time and performance. The boot process has significant differences with work processes. Moreover, decreasing boot time may actually increase application start times.

Can you have metrics that show the real effects of any tweaking? In theory, yes. But in practice, no.

During the Windows 98 era, I conducted a study on the influence of the ConservativeSwapfileUsage registry key on overall system performance and used mathematical statistics methods to analyze the results. I found I had to conduct hundreds of tests to get accurate and trustworthy system performance results. Do you think someone can spend a week or two accumulating test results to determine the effects that can be achieved by tweaking Windows? I think the answer is no.

Windows is a complex operating system with background processes that may affect performance test results. Therefore, results from repeated tests may differ by 2 to 3 percent, or more. The effect of tweaking is, on average, less than 2 to 3 percent. However, after one or two tests, it is hard to say if there is a real difference in results or just random deviation.

So, what about claims such as those mentioned above: "The system seems to be much faster." Are these claims false? No, the system really may seem faster after tweaking. However, it may not actually be any faster. We tend to perceive things we want to believe regardless of their actual existence.

Have you seen how wine tasters work? They taste numbered rather than named wines. The blind method makes the comparison valid. However, when you know what you are comparing, there is no way to avoid subconscious reactions. Unfortunately, this is why useless programs may sell very well. Just believe the computer must be faster and most likely you'll perceive that it is.

Ten years ago I wrote a program to improve Windows performance on Pentium I computers with certain hardware. The program didn't work with any other hardware, but its description was very convincing - so much so that several e-mails I received from users demonstrated the power of suggestion. Users wrote feedback such as: "The log file says 'not installed'; however I am SURE it is, because things seem A LOT faster."

Now let's turn to another side of "tweaking theory." Do you believe developers are missing opportunities to enhance Windows performance, or that they don't consider tweaks? I don't. The Windows performance team inside Microsoft runs a variety of performance benchmarks/workloads on a wide spectrum of computers.

At first, the results of the struggle for performance may not seem very impressive, but a 5 percent difference in performance difference is a large difference. And a couple of simple and easy tweaks may result in performance increases that are as high as 10 percent.

You may not feel that 5 to 10 percent performance increases can really make a difference, but they actually can. The primary operational system task is to run user applications. The fewer resources the operating system uses, the faster applications run. Suppose Windows (n-1) might normally use 10 percent of computer resources and an application uses the remaining 90 percent. Or suppose, instead, that Windows (n+1) is twice as efficient (a great achievement) and uses 5 percent of computer resources. In that instance, the application will run 95/90 = 1.056 times faster. This example shows that a significant difference in the operating system development can give only a small gain in overall performance. And this is a huge contradiction for tweaking to improve performance. Tweaking just can't give the results you want.

I asked Michael Fortin, Distinguished Engineer for Windows, if the Windows team studies published tweaks and tips. Fortin said, "I asked a bunch of [team] people and was a little surprised. What I found is that most people do things, but collectively it all started to also look like buzz about nothing. With one exception: uninstall stuff you aren't using."

So, I conclude that almost all Windows tweaks are fairly useless when it comes to speeding up your computer. To achieve significant results, you'll need to buy a new computer or upgrade your existing system; at the very least, you'll need to uninstall some rarely used programs.

Finally, I want to give you some tips on considering a few commonly suggested "optimizations":

  • If you see a tip to set SecondLevelDataCache registry key, keep in mind that it has not been used since Windows 2000 SP1.
  • If you see a claim that the DisablePagingExecutive key may increase performance, it is false. It actually may decrease overall performance; however, because it decreases response time, the system seems faster.
  • Setting the processor or core numbers in Msconfig cannot speed up booting because all cores are used by default.

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About the author

Igor Leyko photo Igor Leyko has worked with computers since 1974. He is a Windows System & Performance MVP. This article is an abstract of an article that is published in Russian here.