Superfetch - Is It Worth It?

any new information on this? sorry to bring up an old thread.

 

http://www.google.com/search?q=supe...s=org.mozilla:en-US:official&client=firefox-a

 

No, no news. Simply put, unused memory is wasted memory.

Gary

 

Pretty much sums it up. If anything, it will only save you a couple of seconds. There are some benchmarks out there if you google.

Superfetch actually makes more sense than those people who try to shave off 2 seconds from their boot times. Considering you launch programs far more often than you'll ever boot you computer, it is optimizing all the right things for the wrong reasons. It is like spending money on airbags but failing to get good brakes.

Superfetch is useless if you keep the same programs open all the time, like yours truly.

Boot times are just as useless considering technology has allowed computers to use standby mode for years. An equivalent analogy is like making a better zip disk when you could just use a flash drive.

 

Atleast Superfetch preloads them into memory for more efficient operation.

 

The way Vista is coded you don't have a choice. Without superfetch Vista runs like total complete crap. I disabled it a few times and the trade off was not worth it. The 5 minute disc thrashing on full boot is worth the wait IMO. With Vista you really need to use sleep but then there is the power trade off. So I ended up using sleep and buying a 12 cell battery to keep the sleep mode under control. Can't wait for something better.. hopefully seven will bring us a brisk OS again.

 

You could use "Hibernate" instead.

 

I know.. but sleep is so much faster. For a long time I could not use the power saver mode since my wireless was a really old smc and vista has a bug for some of the older 802.11b with connection issues. I switched over to my quest wireless and now the power saver mode works. So between the 12 Cell and power saver I more then doubled my battery life

In other words its best to leave vista as MS intended for the best experience. That means to keep it in the ram as much as possible.

 

LOL.. 6 pages of useless arguement on the same answer.

Superfetch works!!! There's no doubt at that.

If you know what superfetch is, you'll know it's working. Whether or not you find superfetch is beneficial, it's your call.

I personally find no use for superfetch because I keep my program open at all times and i never shutdown or restart the computer. The program does not have to load thus have 0 start time. It's better than both turning on or turning off the superfetch.

Superfetch isn't all that useful in my opinion.
There's basically 2 situation, computer with minimum amount of ram and computer with excess amount of ram.

Minimum ram - slightly better to turn superfetch off.
Excess amount amount of ram - just leave every one of your program on. The startup speed of your program will improve by infinity times.

 

1) superfetch can mess itself up and result in disk trashing. if it does, delete everything in c:\windows\prefetch, disable it, reboot, re-enable it, and reboot 1 or 2 times to have it start prefetching nice again.

2) superfetch evolves => it doesn't perform best right from the start.

3) superfetch makes bootup quite faster, and so does it make logon quite faster.
i have 2 ssd's in raid 0. with superfetch enabled (and some reboots and prefetch-organisation done), i get to desktop before the sounds of welcome to windows (with the logo shining up) has finished playing. the logon sound plays while the welcome to windows sound plays. and the moment i am on desktop, the system is 100% responsible and starts all my apps at an instant.
if i disable superfetch, i can see the logon-screen, the sounds are split, and after seing the desktop (5 seconds later than with superfetch), my apps start up slow.

so, superfetch helps to make your system much more snappy.

from what i've seen (and that's the next point):

4) superfetch has highest quality on ssd's. it has lowest quality on 4200rpm disks. there, it often leads to disk trashing, essentially slowing the system as it tries to prefetch apps after logon, and i don't even get the required small amount of disk-resources to load an app then.

so try it on and off, play around, and find what fits for you. i have some notebook users where i've turned it off for them, and their system is much more snappy. i have other systems (like all the ones at home with ssd's, but others, too), where turning it off would hurt performance.

 

actually, superfetch helps for something else than just startup: keeping your ram "warm". that means, if you ever used xp at work and went to lunch, you may have noticed that the system feels like sleeping when you're back. reason: it dropped all not-really-active apps down to disk (pagefile) as it thought they're useless by now.
superfetch actively prevents this by directly start to superfetch after screensaver/lock is gone (and it looks to not even loose it's cache if the memory is not needed for anythign else), so your app are responsive after the break.

but vista works much better with the memory no matter if superfetch on or off anyways. xp is terrible sometimes (espencially that after-the-break-slowness is terrible )

 

Who invented the terms superfetch?

 

Microsoft did. Since XP's "pre-loading" memory tool is called prefetch and Vista's tool is much better. So MS called it superfetch.

 

Not sure if this was covered, but superfetch isn't worth it if you have files larger than your RAM can load.

mpq files for World of Warcraft try to load on startup of vista but they are well over 3gb a piece and there is more than one... Unless you have a 32GB system it isn't worth it for anyone that uses large files.

Comments?

 

True, superfetch doesn't work as well when memory is less than the size of the files it tries to pre-load. For the MPQ files though, I think WoW's game engine doesn't load the entire file. It doesn't make sense to load all 3 GB's of the file when the machine only has 2 GB. It only loads what the game engine needs, but Superfetch probably doesn't see it that way and ends up trying to load the entire file. I wonder if Superfetch does some sort of on-the-fly compression with the files it loads into memory so when it does need the file, all it needs to do is uncompress it and off-load the oldest set of unused file(s) to clear space.

I think I went off on a tangent by accident...

 

The sole reason I'm still on XP. Disabling it makes vista just suck.. only way I'm upgrading to vista or 7 is if I can get 32+gb of ram.

I do have a mini-vista install that seems to be working quite well. Once my new gt735 gets here I'll tweak to hell and report for everyone.

 

Yes, superfetch is worth it. And no, it's not just a "dumb" prefetcher that either loads, or doesn't load, entire contiguous files. It works with the memory manager to both prefetch data and code from files on disk and also from the paging file.

Even under normal operating circumstances, if you've got a file that's larger than total physical RAM, it is literally impossible for 100% of that file to all be loaded into RAM at the same time. Instead, portions that aren't currently being accessed/used would be paged out to the paging file (and if you've turned that off under some mistaken conception that doing so would speed up your system, now you know why you're wrong).

It would therefore seem to follow that superfetch, in applying its algorithms, would prepopulate physical RAM with those portions of a too-big file that were most likely to be used first, and who knows, would most likely prepopulate the paging file with the rest of the file.

On a side note, folks who continually complain about superfetch might want to check to see if they've disabled their paging file or set its size to a very suboptimal value; since superfetch works hand-in-hand with the paging file as well as with files on disk, is essentially like tying one hand behind the back - of course superfetch will perform under par if it's been intentionally stripped of half of the resources it uses to do its job.

For those who want some recreational reading on the topic, Mark Russinovich has a nice, short little discussion that doesn't get too in-depth on TechNET here, as well as a blog entry on Pushing the Limits of Windowshysical Memory that has some further discussion of superfetch, in addition to a really good discussion on a lot of deep-down memory issues Windows has to deal with - as well as a screenshot of the task manager from a Windows Server 2008 running 2 Terabytes of RAM.

Were I you, I'd stop worrying about _Vista and retire the XP installation unless you have some app you have to run that cannot run under _Vista. I just got a forced upgrade to _Vista two months ago when my 6 y.o. VAIO finally bit the dust; I replaced it with the _HP DV7 series in my signature line, and I have to say, without doing anything to the system other than removing some of the more obnoxious bloatware (like the idiotic games _HP tries to push), and running the trial version of Norton 2009 that was preinstalled, this system is pretty darn fast. So much so that now when I have to go back and get something off the VAIO (I scrounged around and stuck an old hdd back in it, so it's gimping along now until it eats that drive, too), I feel like I'm going from a 2007 model sedan to a Model-T - yes, XP is beginning to feel almost that clunky. Oh, and don't "tweak" just for the sake of tweaking; odds are, you'll tweak yourself into suboptimal performance.

 

Do you deal with files > 4gb? Because I just watched a vista boot up try to load the entire 16GB of world of warcraft into ram.. 0FREE Dump a MPQ file to 3GB free then try loading the next one... Repeat until it had loaded the last file. Then it starting loading my Database Files and left no World Of Warcraft files in memory.. After 30mins I stopped watching. I'll admit I don't understand all of it, but I will say that it doesn't seem to handle large files well.

 

Gotta be something in your system then, 'cause I've got _vista running on defaults, and it doesn't have a lick of trouble with the very large image files I tend to mess around with.

 

lol, could it be because you have 6gb of memory in your new laptop? with that amount of space, vista is very happy. 3gb and up is what i call a sweet spot for vista users. i also have 6gb of memory in my vista desktop and 100+ processes easily.

 

I am curious, does anyone know if Windows dumps Superfetch contents from RAM when entering sleep or hibernation?

 

Thats a good question. I think it keeps it in memory anyway, as long as no other active application requires the space.

 

Why would it? Wouldn't you want it copied to and from the hiberfil.sys so it does not have to be refreshed upon waking up?

Gary

 

I understand that from a practical point of view it makes no sense for Windows to dump the Superfetch cache on sleep/hibernate, but I ask this because my hard drive goes nuts after resuming from either of these states. I can even watch my Task Manager as the Cached Memory goes up and the Free Memory approaches zero. It is because of this observation that I pose the question.

 

That may have to do with the fact that superfetch not only keeps track of what you are most likely to use, it also keeps track of when you use it. So if you put it to sleep/hibernate at time A, and then wake it up at time B, when the data "tells" superfetch that you're most likely to be using a completely different set of code/data than what was prefetched when you put it to sleep/hibernate, it would (I presume) start prefetching all of the time B stuff, which because it wasn't prefetched at all at time A when the system went to sleep, would require pulling all of it fresh from the drive.

 

In Task Manager, the actual memory available for use by app's is 'Cached' + 'Free'. Vista will gladly give 'Cached' memory to apps you open up as needed. Vista and Windows 7's memory usage algorithms take much better advantage of memory, improving on perceived performance of the computer.

 

I guess since your not accessing those image files 200+ times a day it might make a difference, MPQ files are much like database files for games. It loads only one it needs, but vista seems to "flag" them as popular files. It's been a problem gamers have had with Vista since day one, Not just my system.

I'm not trying to ruffle feathers, but I know what I see, and I know what others have seen on their systems. Large Files for games + SuperFetch causes a large ammount of disk trashing.