SuperFetch makes Windows faster: Here’s how

All the “for” and “against” debate kept aside, the fact remains that Windows continues to be the operating system of choice for most small and midsized businesses, as well as enterprises with full-blown IT departments.

Windows 10 advertisements, especially those targeted at enterprise customers, look to promote the idea of fast boot (less than 15 seconds). This goes without saying: Quick boot and quick loading of applications continue to be key parameters on which end users evaluate operating system updates. This means you can get more work done quicker.

Windows did the blunder of the millennium with Windows Vista, and after a well-regarded Windows 7 rollout, released the grand mess of Windows 8. The negative feedback that flew from bottom to IT gatekeepers and decision makers was – the operating system is “slow.”

In light of all the negative sentiment that’s grown around Windows operating systems in the past decade, the focus automatically lands on functionalities, settings, customizations, upgrades, tools, and techniques that, well, speed things up. SuperFetch is a technology that promises precisely that – speed. Let’s understand how SuperFetch works, why it’s different than other similar techniques used earlier, and why you’d do well to not disable it in your Windows.

Advanced caching and trace management

how SuperFetch works

SuperFetch delivers the dual benefit of fast OS boot, and fast application loading. The core principle it uses to achieve both these outcomes is pretty easy to grasp.

For the OS to load, or for any application to load, we need data files, which need to be accessed in a specific order. Now, the best-case scenario for quick loading is, when:

  • The files are available in fast access memory, that’s RAM.
  • The files are placed in the sequence they’ll be needed in.

SuperFetch analyzes the booting, and the application loading, and prepares a trace document with all this information. This trace document, then, helps SuperFetch prepare beforehand, so that it can arrange the files in a manner that enables the fastest loading.

Context of timing

Another superb functionality of SuperFetch is its ability to understand “when” you access certain applications. It uses this information to store those application files in RAM that are likely to be called sometime soon. This timing information is also captured in the trace files it manages.

ReadyBoost: Helping SuperFetch do better

Any files that are not accommodated within RAM are stored in a secondary fast storage. In most cases, this is the hard disk. Now, this is where ReadyBoost comes to the fore, and tries to use faster flash storage for files that can’t be stored on RAM, instead of using disk storage.

Of course, this becomes important in system with low RAM (1GB or less), and is not too evident in systems with large RAM (2GB or more). For low RAM systems operating Windows Vista or higher, SuperFetch and ReadyBoost combine to deliver the maximum observable advantage.

Which Windows versions does SuperFetch work with?


Apart from Windows XP, SuperFetch is supported by all other Windows versions. Windows Vista, Windows 7, Windows 8, and now Windows 10 – it works with all. In Windows 8 and Windows 10, the SuperFetch service is smarter than ever.

That’s because it can automatically switch itself off when it identifies that the solid state device being used is fast enough to offset the advantages to be had by implementing SuperFetch. Also, SuperFetch is enabled automatically when a slow SSD is detected. In Windows 7, SuperFetch is disabled systemwide automatically if a fast SSD is detected.

Should I disable or enable SuperFetch?

Google it, and you’ll see contrasting opinions. Much of the thought process behind disabling SuperFetch in Windows stems from the prevalence of misconceptions around how it works. Here are three opinions “experts” harbor, but which deserve a deeper consideration, and ultimately, are not really true!

Misconception 1: SuperFetch limits free RAM

With SuperFetch activated, you’ll observe that the proportion of your computer’s RAM designated as “free” will be lower than otherwise, and the proportion of memory designated as “cached” will be higher than otherwise.

Reason – SuperFetch keeps files necessary for loading frequently used applications in the memory, to enable quick access. This increases the cached memory component.

Does this mean that new applications won’t get memory to load quickly? Not at all. That’s because in Windows, SuperFetch gets lower priority than memory allocation requests made by new applications. So, even though the free memory seems low, a large portion of the cached memory is also available to new processes and applications. Yes, you get fries with that! But keep them saltless, French fries do not need any extra salt!

Misconception 2: To improve system performance, disable SuperFetch.

Nothing could be further from truth! Several guides about “improving Windows OS performance” suggest that you disable SuperFetch. However, most people suggest this out of lack of knowledge about SuperFetch, and in congruence with the general belief about “switch off what you don’t need in Windows.” If Windows is not performing well on a computer, disabling SuperFetch can only slow things down and not help you out at all.

Misconception 3: SuperFetch slows your boot speed.

Again, this is in total contrast to what SuperFetch delivers to your computer. SuperFetch works to make your operating system’s boot speed better than before by arranging the files needed to boot in the sequence they’re needed. Secondly, a question you should ask yourself is – how many times do you boot your computer daily?

The speed advantage that SuperFetch offers in application loading can’t be offset by even a significant spurt in the time taken to boot.

The answer to the question under discussion, then, is that there’s no reason for you to disable SuperFetch in Windows.

Speedy booting and quick application launches save vital minutes daily, and considering that SuperFetch enables this on every computer in your organization, the potential it has is immense. Use the information shared in the guide to check whether SuperFetch is activated in all computers, and empower your employees with an empowered operating system.

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16 thoughts on “SuperFetch makes Windows faster: Here’s how”

  1. This could explain why my Laptop with Windows 10 constantly has more RAM taken compared to other computers with Windows 10 even when I’m not running any extra background programs.

    1. Benjamin Roussey

      Hi Ben,

      Interesting comment. I would have covered this (arguments to switch off Superfetch), it’s just that there’s not a lot to discuss. Windows 7 switches Superfetch off by default for SSDs, because there’s no value to be added for them. So, if it’s switched on for your system AND you use SSD, turn it off (although leaving it on doesn’t hurt either).

      Thanks. Have a terrific weekend over there.

  2. Very well-reasoned article. Take that, superfetch disablers!

    The only problem is that this runs contrary to my actual experience. Superfetch has spikes of disk usage (like, 100% disk usage) on my windows 8 laptop that completely outweigh any boot speed or other well-rationalized advantage you’ve listed, so it is and will remain disabled on this machine.

    1. Benjamin Roussey

      Hi Damien,

      Thank you; I appreciate your comment.

      You seem certain it was Superfetch that caused the CPU usage spike. Did disabling it immediately solve your problem?

      There could be other reasons behind excessive CPU usage. Some remedies I trust and recommend:

      Disable Windows search service
      Update drivers for Windows 10 Creators Update
      Disable startup programs

      OK, have a fine day over there.

  3. I had the same as Damian on my Win 10 laptop (constantly running at 100% disk usage) then it would shut down sometimes after only being on for 10 minutes so I disabled Supertech no more problems and running like a dream.
    Benjamin, I take what you say about Superfetch but if it works better off so be it.

    1. Benjamin Roussey

      Hi John,

      Thanks for letting us all know.

      I’m sure, though, that there’s more to the Superfetch experience that you (and I am sure a lot of others) have had.

      I’d admit that for anybody who’s happier switching off SuperFetch, there’s every reason to keep it that way.

      How recent was your experience though?

      I hope your day is going well.

  4. Superfetch is disaster !!! Freezes computer with this 100% disc space, impossible to work ! And, worst of all, it reenables itself after some Windows updates, luckily, only first time hard to find solution. I think, it should be disabled on office computers unless you’re working very few systems on very dull, boring job: if you running more than few system interchangeably (like sometimes working with Java Eclipse, sometimes with databases, sometimes trying Jenkins, Atlassian JIRA or some some testing system), then there’s no way Superfetch can guess what you need and do you any good: it will only freeze your PC and destroy your work

    1. Benjamin Roussey

      Hello Rasa,

      I appreciate your comment, and respect your opinion.

      You make a very valid point – Superfetch is designed to optimize resource consumption with many assumptions and generalizations. These generalizations don’t stand for someone who’s using the PC for high-intensity work, like you described.

      My analysis has always indicated, even if very small, improvements in Windows performance occurs with Supefetch on then it makes sense to use it. That said, if merely switching Superfetch off drastically improved Windows performance, and switching it on again disrupts the performance, then I guess there’s no reason to switch it on. I haven’t had that observation personally.

  5. I have spent hours researching the fix for 100% disc usage, which recently made my Windows 10 system nearly unusable. The numerous how to videos and articles that explain the steps to turn off Superfetch indicates something is amiss.

    My system was stable until recently and I had not installed any new software prior to the 100% disc usage issue. The system operates normally when I disable Superfetch.

    This message is a call to the experts out there who could research the issue and identify what has changed to cause so many people to experience problems with the Superfetch. I would love to turn it back on.

    1. Benjamin Roussey

      Thanks for the comment Duane. I am sorry about your issues with SuperFetch. Perhaps I should write an article just on that topic.

      I hope your Friday is going well.

  6. This is absolutely NOT true.

    Exactly about 30 minutes ago, my laptop starting slowing down TO A CRAWL. Every time I tried to open ANYTHING (the browser, the task manager, even the goddamn Start menu) it took around 3 minutes to do so. Do you think that’s normal? Do you think that’s good performance? Oh, by the way, I own an Alienware 17 R4. It’s a powerhouse. I’ve never had any trouble until NOW, and you know what I see in my task manager, inconspicuously taking up a ton of CPU usage? SUPERFETCH. I googled it and (not thanks to articles like this one) luckily I learned that the best thing I could do was disabling it. I did, and voila! My powerhouse laptop is running at its full capacity once again, buttery smooth.

    So clearly YOU are the one with the lack of knowledge, so it would be appreciated if you stopped posting this garbage and start telling people the honest truth. Thank you very much.

  7. I’m the IT Manager for a small non-profit and I can say that in 100% of the cases where I’ve disable superfetch on a Windows 10 computer the performance has improved immediately and substantially. Over time, every computer in my company has experienced an issue of 100% flat disk utilization and, without fail, disabling superfetch has mitigate the issue and returned the computer to normal, fluctuating disk utilization. I believe that the concept behind Superfetch is well meant however I’m unconvinced that the service functions properly. This is something that Microsoft really should look at because Superfetch is enabled by default on a Windows 10 install. Folks who don’t have an IT department to help them out may never know that this rogue services is what’s causing their problem and will spend large sums of money having a professional troubleshoot their problem. In the end, disabling Superfetch is likely the solution any technical individual will employ. Very unfortunate that MS can’t own up to this issue. Hopefully they do better next time.

    1. Benjamin Roussey

      Hello Tony,

      Thanks for your detailed comment. And the way you described your experience, it does warrant a deeper look at Superfetch from my side. I may have to write another post on this topic based on your salient feedback. Outstanding comments on Microsoft. Interesting.

      Merry Christmas over there. I hope your week is going well.

  8. Superfetch has been changed in Windows 10 a bit since 7.

    In any case you should disable it if you have your windows os on a SSD, windows should disable it but if it doesn’t you should disable it and prefetch.

    It does make windows run faster at the cost of more HDD usage.

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