SuperFetch causing high CPU usage (Windows 8)

Question

Hi all,

I have a fairly new, custom-built desktop with Intel Core i7, AMD 7700HD video card, 16GB memory, solid state drive and Windows 8.1. But the overall performance of the PC is a bit too sluggish for the specs I have.

So I opened Task Manager > Performance tab, and noticed that the overall CPU usage stayed at around 30-35%. Then I switched to the Processes tab, and couldn't find any programs that had high CPU usage, so I started looking at some of the Windows services.

I noticed a process called "Service Host: Local System (Network Restricted)", and it was using about 25-30% of the CPU! And underneath that, it listed 9 Windows Services (Offline Files, File History Service, SuperFetch, etc, etc). However, Task Manager doesn't allow you to see the CPU usage associated with each individual Windows service (can that be done?).  So I started disabling all the different services to see if that made any difference.

Lo and behold, the moment I stopped the SuperFetch service, overall CPU usage dropped within seconds down to about 5%! 

Then I re-started SuperFetch, and noticed the CPU usage spike back up to 30-35% again within about 1 minute. I repeated the process stopping and re-starting it, and could consistently duplicate the issue. So SuperFetch is the culprit causing my computer to run sluggish!

Doing some research on the web, I see people in other forums saying "don't disable it", but there's no explanation given anywhere.

So my questions are:

1. What exactly is SuperFetch?Does it have anything to do with drivers?
2. Why is it causing such high CPU usage???
3. Will keeping SuperFetch disabled cause issues? If so, what could happen?

Thanks in advance for help!

Answer 1

Hi,

The answer to your first question: What exactly is SuperFetch? Does it have anything to do with drivers?

SuperFetch is a service that was introduced with Vista and has been part of Windows ever since. It tries to speed up your computing experience by pre-loading parts of programs into memory with sometimes detrimental effects as you had to experience. It tries to determine which software you use and stores parts of it to the Windows folder. SuperFetch is a technology which allows Windows to manage the amount of random access memory in the machine it runs on more efficiently. SuperFetch tries to make sure often-accessed data can be read from the fast RAM instead of the slow hard drive. SuperFetch keeps track of which applications you use most and loads this information in RAM so that programs load faster than they would if the hard disk had to be accessed every time.  Windows SuperFetch prioritizes the programs you're currently using over background tasks and adapts to the way you work by tracking the programs you use most often and pre-loading these into memory. With SuperFetch, background tasks still run when the computer is idle.  However, when the background task is finished, SuperFetch repopulates system memory with the data you were working with before the background task ran. 

Answer to second question: Why is****SuperFetch causing such high CPU usage?

As you are using Solid State Drive (SSD), ****there are possibilities that the SuperFetch service is conflicting with the performance of SSD thus causing high CPU usage.

Answer to third question: Will keeping SuperFetch disabled cause issues? If so, what could happen?

SuperFetch is designed to cache often used files. On a slow mechanical drive this can speed up operations. As you are using Solid State Drive which have a very fast access time, the caching feature isn't needed and SuperFetch can be disabled.

Please feel free to reply, in case if you need any further assistance or information on this issue.

Answer 2

So your saying that Microsoft knows that Windows runs too slow and created StupidFetchin a lame attempt to artificially make it seem faster at the expense of users' hardware but that causes more problems that it actually solved?

Seems like a typical Microsoft solution to me.

Are there any other stupid things like this we can disable?

Answer 3

I've found that by stopping the superfetch service in task manager (not disabling it) and then deleteing all files in the prefetch folder, and then immediately restarting the computer the prefetch service will generally use less than 20 MB of RAM for a good while. Things will be a little slow until the prefetch folder is repopulated; thus I let the computer idle for a few minutes before I use it, and expect applications to open slowly the first time.

Answer 4

Hi, I have the exact same issue mentioned, but do not have an SSD. I have a regular HDD. It is not common for this service to do such a thing, but it has been doing it for the past few weeks. It has also been taking lots of disk usage. Strange enough, the problem goes away for a minute or two when I clear my prefetch folder, but comes back. I have also tried stopping the service, which does seem to fix it, but then again disabling the service disables prefetching altogether, so I don't consider it a fix.

Answer 5

Thanks. This has been very helpful. I was wondering why my laptop (non-SSD) isn't experiencing the same thing. I checked my laptop to see if SuperFetch was running and it was. 

I'll have to keep it mind to disable SuperFetch if I ever upgrade my laptop to an SSD. Most average users wouldn't even think to do that, however. You would think that the OS should do it automatically if it detects one. I don't know. But overall things seem to be running better now.