SuperFetch and SSD

Is it necessary to turn on Superfetch with an SSD? I'm worried that whenever I boot my computer (few times/week) Windows will start loading stuff from the SSD to the RAM, thus causing excess wear/tear on the SSD (7 GB free RAM is a lot to fill) because I may not use all the things it's loading. Also, is the difference in application loading time between SSD and Superfetch RAM even noticeable?

 

Its recommended by manufacturer that its turned off along with defragging

Keep in mind that SSD's wear out on WRITE and not READ. Superfetch is READ from the SSD and write to RAM.

 

Defragging has always been disabled for me. If the READ does not wear it out, then why do manufacturers recommend to turn it off?

 

Doesn't make sense to me.
Superfetch caches dynamic contents meaning it introduces extra write.
Since SSD excel at reading speed, Superfetch should be turned off as Superfetch is suppose to compensate for Harddisk slow reading.
Edit:Oh you said turn off as well but your explanation isn't clear...

 

Well to initially compile the files to be fetched then yes that part needs to be written, but once your habitual programs are compiled then it is then written to the RAM. It does get updated dynamically depending on your habits. The write should still be minimal compared to the read

I still recommend it to be turned off because SSD's are naturally fast.

I did a test before and it took about 2 mins for a traditional 5400rpm hard drive to fill up 4gb of my RAM of fetched files. A SSD should take a fraction of that. Loading the program directly will be as quick making superfetch redundant.

 

http://blogs.msdn.com/e7/archive/2009/05/05/support-and-q-a-for-solid-state-drives-and.aspx

 

sgilmore62,

Don't have the link handy right now (on a Mac), but what MS recommends (and actually does with a clean install of Win 7) with a RTM version of Windows 7 is to leave SuperFetch on. Defrag is turned off for the SSD, but is still enabled for any mechanical HD's you may plug in to the system.

They studied this and found that SSD's are not fast enough yet to negate the need for SuperFetch and have changed their tune from what sgilmore62 quotes above.

As long as you do a clean install of Windows 7, then all you need to do is enjoy the SSD experience - no further tweaking/worrying necessary.

Cheers

 

Sysmain has been turned off on my machine and I did not turn it off.

 

I'm very interested in that link. Could you see if you can find it? So far, I thought they'd be doing a benchmark to determine the random read speed, and set the settings accordingly.

Thank you.

 

That is exactly what they were doing, but are now running multiple benchmarks to determine if/when certain services are needed or not.

Look further down the link to see more details on how Win 7 determines how to set itself up.

See:
http://blogs.msdn.com/e7/archive/2009/05/05/support-and-q-a-for-solid-state-drives-and.aspx


The other problem is that some SSD's do not report themselves properly to the O/S as SSD's...

Hopefully by SP1 (this summer/fall!) of Win 7, these issues will all be sorted out.

Cheers!

 

That link only says they enable it for bad SSDs. According to it, good SSDs would have Superfetch disabled, alongside ReadyBoost, Defragmentation and Prefetching. Please stay precise in your posts to prevent misinformation.

 

With my Intel X-25M G2 80GB (one of the fastest SSDs out there), SuperFetch was left on by Windows 7 Professional. I haven't seen any reason to turn it off, so I haven't touched the setting.

I wonder if there's actually any data proving that SuperFetch does introduce extra wear on SSDs and/or that there are no negative performance impacts by turning it off.

 

Isn't logic sufficient? Superfetch = stuff loaded to and from the SSD to and from RAM (mostly SSD -> RAM I guess, but still some RAM -> SSD motion), so more write wear.

And I've always had Superfetch turned off, even with HDDs, since it incurred too much HDD activity upon boot.

 

They fixed that on Win7. On Vista it used to thrash the disk for 2-3 mins as soon as you log into windows. Slowed down the startup process.

They've delayed it on Win7 if i remember.

 

I am very precise - but also trying to stay concise too.

Sorry, but there is no such thing as a 'good' SSD yet.

They don't exist in a vacuum, they depend on the system they're in.

Although the Intel G1/G2's are the best of today (and have been since their introduction), they still do not magically transform the platform they're on.

On an AMD Opteron desktop (client's) an Intel G2 160GB with the newest firmware does not impress (too much... or, at least as much as it should). Why? Because the platform is horrible. Still, with money to burn (client), there is still a performance difference compared to mechanical HD.

Cheers!

 

there is no wear/tear AT ALL when READING from the ssd.

and the WRITE to ssd will not bother your wear/tear of the drive ever. your laptop will be obsolete before the ssd will have too much writes (think about, in years)

and yes, superfetch might still help. ram is still an order of magninude faster than an ssd. but the os determines that itself when doing WEI. and will disable it if it's not needed.

in short: don't bother.

 

Let me explain some things here.
What Superfetch does is it preloads data to your computer's memory that it believes will be needed soon. Superfetch is basically an improvement of Prefetching, which (unlike Superfetch) is also available (and enabled by default) on XP. Unlike Prefetching, Superfetch will precisely monitor your computer usage pattern. For example, after some weeks it may be able to say "Okay, the computer has been turned on, it's Sunday evening, so I guess the user will be using Media Center to watch TV like he does nearly every Sunday evening, so I'll preload that to memory so it will load faster." This also tells you that the benefit you get from using Superfetch may vary over time, so if you're evaluating using it, keep it enabled for some time to be able to see whether it actually helps for your specific configuration or not. This also tells you that Superfetch is one of the reasons why Vista seems to need so much RAM. It definitely needs more RAM than 7, but some of it is actually prefetched data. If Windows completely filled your RAM with prefetched data, it would immediately free RAM whenever it needs to load something that has not been prefetched. Full RAM is not necessarily a bad thing, while empty (==completely unused RAM) RAM definitely is.

In other words, Superfetch basically reads, while the amounts of writes (or, to be more precise regarding SSDs, erases) is virtually irrelevant. With the NTFS access timestamp being disabled by default in both Vista and 7, you don't have to have fears that Superfetch could cause much wear on your SSD aside from some Superfetch management related data being written.

On a sidenote, Intel promises that the x25-m (every version) will last for at least five years even when writing 100GB per day to it. By then, the drive should be well outdated. Also, WHEN it fails, your data will be safe. It will still be readable, you just won't be able to write anything to it anymore. Again, this specifically for the x25-m, many other manufacturers don't focus so much on things other than speed.

Yes, it also didn't do that for me. However, when I compared Superfetch and Prefetching on vs. off, I found overall performance to be better when both are off. To accomplish this, you can go to HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters, write down the values of "Enable Prefetcher" and "Enable Superfetch" (so you can later revert to the previous state), set both to 0 and reboot.

Right, on Windows 7 you don't have to bother. However, if you know what you are doing, you can still try different settings and see if it noticeably increases performance, which (depending on your specific configuration) might well be the case, as SSDs are still not mature.

Vista however won't set these features according to the quality of the drive it's running on. Manually changing them might be a good idea here, depending on your case, but again ONLY if you really know what you are doing.

At any case, you should always disable (scheduled) defragmentation on SSDs, due to the fact that the operating system doesn't have any idea about where specific data really is located on the SSD. Defragmentation will cause a substantial amount of wear on your SSD.

 

I'm with Dave here. I'm tired of people worry about the limited write cycles on the Flash drives. It isn't even technically a "write" that knocks on the lifespan of SSDs.

It's called a write cycle because that's the jargon for it. But it doesn't translate correctly to casual users and I wish people quite quoting it without a little research.

 

Why would Superfetch involve more writing to the hard drive?

 

It's initial speculations.

In the long term....

 

Pure speculation but maybe Superfetch needs to update its logs/DB of stuff to load, especially if your most often used programs change frequently, etc.

 

and if? then it will be some kilobytes each boot. so you'd have to boot on your 256gb ssd for a million times to fill one or two gigabytes of writes. so a quarter billion to fill the ssd once with such logs. and you have to do that 10000 times, to maybe kill it.

so how big is the chance that you boot your laptop 25000 billion times?

in short: learn how much write cycles you have to understand that no ordinary daily usage case can hurt it.

 

Put it to the test. Run a program that monitors disk activity

Disable SF service, restart, wait till desktop is completely loaded up then manually enable superfetch again. It should start caching into the free RAM.

 

In the long run, SuperFetch will help your load times. That's why people turn it off when they run benchmarks.