New I/O Features

One set of features we have held off on discussing in-depth until now have been the I/O related features in Vista, including ReadyBoost, ReadyDrive, SuperFetch, and the new networking stack. We'll get to the new networking stack in a bit, but first the Ready features and SuperFetch merit a bit of discussion.

SuperFetch

Depending on the scenario, a great deal of computing time is spent waiting for data retrieval due to processors being significantly faster than the mass storage devices. To that extent modern computers have a hierarchy of several levels of data caches to store and manipulate data, ranging from registers and L1 cache down to hard drives and their own cache. This system of cache layers works very well in hiding the speed differences between various layers, but there are still large gaps between places such as the CPU and RAM, and RAM and hard drives. One possible improvement - and certainly the most effective solution that Microsoft has implemented in Vista - is to try to move up required data to a higher layer, in this case by keeping more data in RAM than just the bare minimum.

The result of this is the first I/O improving technology, SuperFetch, a new technology designed to cache as much data as RAM space allows. Previously, Windows XP had a more basic implementation of this idea called prefetch, which used trace logs of programs loading in order to help XP optimize the loading sequence. SuperFetch in turn takes things a step further by not only figuring out what data is required to launch an application, but it actually loads this data into memory as space allows so that if it's needed at a later point the data is already in RAM instead of still residing on the hard drive.

In practice, SuperFetch depends a great deal on how predictable a user is and how much extra RAM a computer has. Veteran computer users will be slightly dismayed at first to find that Vista is actively attempting to use the entirety of a computer's RAM (down to 0MB of free memory remaining), which is effectively the opposite of how XP attempted to conserve as much memory as possible. This looks worse than it actually is, as cached data can immediately be thrown away to make space for an application as required, but Microsoft has nonetheless attempted to clarify things since Beta 2 where the Task Manager would only show total memory usage. Now the Task Manager makes it clear how much RAM is being used for program execution and how much is being used for cache, but this will still inevitably spark a few debates on if full RAM usage is really a good thing. Given that RAM tends to be a low power device operating at near full power all the time (especially on desktop machines), we feel RAM is the ideal underutilized component to try to fully exploit, as it doesn't incur the extra power costs of running at full load like a CPU/GPU do.


However as we mentioned previously, the total benefit is dependent in predictability and excess RAM. As SuperFetch is designed to predict what applications a user may load next and then pre-load them into cache (i.e., a user loads Outlook at 10am every day), it works better for users with routines than those without. Similarly, as Vista attempts to use all RAM for the cache, it can always benefit from more RAM to keep more things cached (a behavior similar to MacOS X).

Index How Much RAM?
POST A COMMENT

104 Comments

View All Comments

  • redpriest_ - Thursday, February 01, 2007 - link

    Did you guys run the 64-bit tests solely on the Intel Conroe platform? Or did you test an AMD based platform as well? Recall that Conroe has a few performance enhancing features that *only* work in 32-bit mode (branch fusioning, for one - some decoder limitations as well).

    That could explain why a Core 2 Duo system might have seemed slower in 64-bit than in 32-bit mode.
    Reply
  • Jeff7181 - Thursday, February 01, 2007 - link

    SuperFetch is by far my favorite new feature of Vista. I put my first copy of Vista on my laptop, which has a 5400 RPM hard drive. Opening apps Outlook and VB .NET 2005 EE weren't really slow under XP, but there were those few extra seconds it took to load that would often leave me tapping my finger on the palm rest while I waited. Now under Vista, Outlook, VB .NET 2005 EE, and IE7 all seem to be able to fit in the SuperFetch cache, as they all open nearly instantly with just 1 GB of RAM. I'm considering upgrading to 2 GB just to see what else I can get to open really fast. :D Reply
  • bldckstark - Thursday, February 01, 2007 - link

    Was superfetch disabled when you tried the Readyboost feature in Vista? Whichever way you ran the test it bears mentioning. If it was off, then how does it do with it on? If it was on, it may make a difference in how it relates to XP.

    Also, as I understand it Vista has a system backup now that creates a "ghost" of the drive. Could you check out this feature and get back to us?
    Reply
  • JarredWalton - Thursday, February 01, 2007 - link

    I'm not sure it's possible to disable SuperFetch, so I'm pretty sure all testing was done with it on. As far as the "ghost" goes, that's part of System Restore which can be disabled quite easily. I'll have to let the other editors say whether it was enabled or not, though. Reply
  • WT - Thursday, February 01, 2007 - link

    What drives me nuts are the plentiful comments about how slow Vista is compared to XP. I mean, anybody hear this before when MS came out with a new OS ? Same thing for XP,W2k,98 ... ad nauseum. Yea, its a new Operating System with more 'toys' built in, what were you expecting ? You aren't gonna load it on your P3/256 RAM rig and enjoy the Vista 'experience'. Damn, this thing runs better than XP on my rig !
    It's understood that it won't be as quick (keep in mind the OS has been available for retail purchase ... 2 days now) as XP, but drivers will improve that performance gap to a smaller number within 3 months time. I waited until just last year to upgrade to XP (W2K all the way for me !) but find myself with 2 copies of Vista and would prefer to dual boot one and go Vista all-out on the other one.
    I griped back in my W2K days about being forced to upgrade due to content (MS games were announced that would only run in XP) so this time around I will be ready.
    DX10? Marketing genius !!! We shall force an upgrade upon the masses !! I upgrade frequently, so DX10 and its graphical splendor is a priority, but if I would have to fork over $200 to actually buy Vista, I would be less than impresssed with DX10 eye candy.
    Reply
  • EODetroit - Thursday, February 01, 2007 - link

    Hopefully, now, finally, Anandtech will start testing motherboards for stability while loaded with the maximum amount of memory. So if the MB supposedly supports 8GB of RAM, you test it with that much, and make sure its stable. I've wanted this done for years... memory is expensive and it sucks to load a MB up and find out it doesn't really work or only works if you cut the speed in half.

    Thanks.
    Reply
  • manno - Thursday, February 01, 2007 - link

    ... no mention of DRM then? No mention of Linux? Personally I hate Linux, but I've switched to it because of Vista's use of DRM. Not all Microsoft's fault, but they put it in there... My computer, my hardware, I choose what to do with it, not MS, not media companies. Why shouldn't I be able to watch High def content on my old, and once expensive non-HDMI LCD screen?

    Get a Mac, Apple is the lesser of 2 evils, they aren't the 800lb gorilla in the room. MS could have told media companies to stuff it. Apple has no choice, it's too small, yet their the ones that forced DRM-Light(TM) on the media companies. MS had the media companied force DRM-Oppressive(TM) on them... how the heck does that work?

    I can't believe you left Linux out of the final comparison, is it as capable an OS, yes. Not nearly as user friendly, but it also has 0 DRM, doesn't phone-home isn't beholden to any one entity. I'm not against DRM, as a whole, just Vista's implementation. BS like MS creating D3D to subvert open standards like OpenGL, then removing it from the OS, using it's monopoly-based-ridiculous-margins(TM) to finance D3D's uptake, again rather than take an existing standard and expanding on it. They create their own to reinforce their monopoly. I know why they do this stuff I'm just peeved so many people don't give two flying f...

    grr...
    -manno
    Reply
  • mlambert890 - Friday, February 02, 2007 - link

    Youre insane dude.. No offense but there just isnt anything else to say. Posts like these always read like the transcript of a Weather Underground meeting in the sixties. "FIGHT THE POWER!!! FIGHT THE POWER!!!"

    Look out! The black helicopters have deployed from the underground helipad in Redmond and are circling!!! Send up the penguin symbol to summon the dynamic duo - Torvald and Stallman!
    Reply
  • Reflex - Thursday, February 01, 2007 - link

    There is no more or less DRM in Vista than in XP, or even OS X. The platform does not determine the playback of DRM'd media, the content does. The choice is simple: If you want to play back DRM'd media, then you have to support the decryption scheme that the media requires to decode it. In so doing you have to legally accept the limitations defined by that DRM scheme.

    It is no different for OS X, Linux, XP or any other OS. They either support the DRM schemes or they do not get to playback the media that uses them. This is why it is unlikely that you will be able to play DRM'd High Definition content anytime soon on Linux. That is the alternative, no support for the content at all.

    Also, you can play high definition content on Vista just fine without HDMI/HDCP on your monitor. You simply cannot play back such content if it is coupled to a DRM scheme that requires HDCP, but that is true of every OS. Any other HD content will play back without issue.

    Again, there is no difference between DRM on Vista from DRM on any other platform.
    Reply
  • pmh - Thursday, February 01, 2007 - link

    The DRM in vista is the major reason that I will only install it if physically forced to. Having bought a new Dell in order to get their very nice 24" LCD last december, I have an upgrade coupon which will lie unused until/unless the DRM can be disabled. MS refuses to display HD on my new monitor using Vista? Screw em. Reply

Log in

Don't have an account? Sign up now