# Any solid reason to turn off superfetch and prefetch for SSD?



## laughingthunder

Microsoft or other places suggest to turn off superfetch if you use SSD, like this one:
http://support.microsoft.com/kb/2727880

but with superfetch and prefetch:
1. there isn't any access write to SSD involve, while access read for SDD suppose to be unlimited
2. ram is faster than sdd

then why should we turn off superfetch?


----------



## Forceman

It never made any sense to me either.


----------



## Geeboi

It's not that it's "bad" to have it on, its just unecessary on an SSD which operates entirely differently in how it handles data throughput compared to a platter HD. Superfetch was designed to overcome access time problems that only platter HD's have, it's simply not needed for an SSD.


----------



## laughingthunder

Quote:


> Originally Posted by *Geeboi*
> 
> It's not that it's "bad" to have it on, its just unecessary on an SSD which operates entirely differently in how it handles data throughput compared to a platter HD. Superfetch was designed to overcome access time problems that only platter HD's have, it's simply not needed for an SSD.


ram is much faster than ssd, isn't it? Then why don't we use ram when there is free ram?


----------



## rui-no-onna

Because one of the *fetch writes small blocks of data to the "fast" portion (beginning) of the drive to speed up program loading. Since all portions of an SSD are equally fast, this workaround intended for HDDs is unnecessary. Alas, still haven't figured out which of the *fetch caches to RAM and which one caches to HDD as advice on various websites tend to contradict each other.

Personally, I haven't bothered disabling Superfetch or Prefetch. The writes are negligible anyway and it's not like the cached data uses up a lot of space.


----------



## wevsspot

With modern SSDs I think all the white noise about disabling fetch (either one) is nothing more than blabber. With first generation SSDs where reliability and durability were a concern, and un-optimized garbage clean up / trim functions were a potential problem I could understand the conservative approach many took on the subject. This is just my opinion, but any one who continues to write on the subject and recommend these SSD "tweaks" is not doing anything more than recycling old news that doesn't really apply in 2013.

Even most of the issues with JMicron controllers have been ironed out now, so I just have a hard time grasping the admonition to always disable prefetch and superfetch when you're using a SSD.

Same thing with disabling the indexing service on SSDs. While you may not technically "need" it on your SSD, you've likely got other drives in your system that would benefit from windows search indexing. Especially if you have to do a lot of file searching and you've got multiple Gb of data.

Specifically for prefetch, you'll get a lot of people that fret over the "automatic" every 3 days rearrangement and defragmentation of boot files and layout on the SSD. Since the location of the files is irrelevant on an SSD a certain part of that point is valid. However, no one has been able to clearly answer whether this defragmentation occurs even if the defrag is disabled on the SSD drive.

At any rate you can completely get around that by simply modifying your registry with the same values I use;

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Dfrg\BootOptimizeFunction]
"Enable"="N"

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\OptimalLayout]
"EnableAutoLayout"=dword:00000000

Lastly, assuming that you had your SSD connected during the Windows installation and you ran the System Assessment tool in WEI - Windows would have determined (based on disk performance) whether it thought you had a SSD installed or not. If Windows determined you had a SSD installed it would have configured itself properly and there isn't much else you need to do.

The Superfetch service will be set to "manual" or "disabled". But even if it is set to manual, you can confirm that the fetch services are not running by perusing your running services in task manager.

The other way to determine whether the fetch services are running in the background or not is to navigate to the Prefetch folder and take a look at when the last files were modified.

Assuming that your OS in on the C: volume, navigate to;

C:\Windows\Prefetch

Look at the seven or eight files in that folder and note the "Date Modified" information. If Windows has properly disabled the fetch services, the "Date Modified" will be the same day as you originally installed Windows (since the files have not been updated due to the fetch services being disabled).


----------



## ohapn

You're talking nosense. Superfetch is a bloatware, junkware.

Microsoft is full of idiots. All Windows since Vista (Windows 7, 8, 10) run a lot of totally unnecessary tasks in the background. I hate when my PC work pointlessly.

The biggest problem with Microsoft's craps that always run automatically (like superfetch, prefetch, automatic maintenance, automatic update, search indexing, ...) is that they

1. shorten the lifespan of the computer by constant usage (it affects especially both the HDD and SSD)

2. increase the power consumption of the computer (the problem is larger when you use a battery powered device, like laptop, notebook)

3. increase the noise of the computer (cooling fans, HDD thrashing)

4. cause performance problems, they waste system resources

5. antivirus programs will scan every time all files that these crap backround tasks read/write, which is another extra waste

So these bloatwares, bull****s from Microsoft are total waste. They harm your computer and annoy you. Even knowing that my PC is working hard without any reason and benefit, annoys me.

That's why I hate newer Windows. That's why I went back to Windows XP SP3. It has the least bloatware. If I were use newer Windows, I would have to do a lot of research and investigating, searching all around the internet to find and disable all bloatwares, unnecessary tasks that run in the background. It's a lot of work to properly configure newer Windows systems.

I want to control my own PC! I want to control what happens. I hate when some ******ed developer think they know better than me what's good for me.


----------



## BinaryDemon

I would imagine if you had a system with a SSD and minimal memory ( ex: 1gb or less ) there might be some significant advantage to disabling superfetch/prefetch.

Otherwise like others have pointed out... Ram is still faster than SSD so Superfetch atleast improves system responsiveness slightly. I doubt prefetch is doing much for SSD's but if your system is a mix of SSD's and HDD's then it's probably wise to leave both services enabled.


----------



## Blameless

I disable superfetch/prefetch on most systems, even if they don't have SSDs. Often the overhead isn't worth the advantage in loading times for what I'm using a system for.

It's pretty pointless with an SSD because most modern SSDs are way past the point of diminishing returns when it comes to drive speed vs. perceptible improvement in general use.


----------



## GeneO

Quote:


> Originally Posted by *rui-no-onna*
> 
> Because one of the *fetch writes small blocks of data to the "fast" portion (beginning) of the drive to speed up program loading. Since all portions of an SSD are equally fast, this workaround intended for HDDs is unnecessary. Alas, still haven't figured out which of the *fetch caches to RAM and which one caches to HDD as advice on various websites tend to contradict each other.
> 
> Personally, I haven't bothered disabling Superfetch or Prefetch. The writes are negligible anyway and it's not like the cached data uses up a lot of space.


You can disable the defragmenting boot optimization, or boot optimized loading and still get application pre-loading.

It appears in Windows 10 superfetch is enabled on SSD boot drives by default. At least it is for mine.

The answer to the original question is no.


----------

