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?
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  • LoneWolf15 - Thursday, February 1, 2007 - link

    Firefox runs just fine on Vista. I've been running versions of it (both 1.5x and now 2.x) on Vista since RC1 (I've tested Beta 2, pre-RC1, RC1, and am running RC2 on a spare box).

    While IE is fast at loading pages on Vista, I've never been able to get used to IE7's UI. After trying to keep my beta-testing experience as MS-app-oriented as possible, I couldn't and loaded FF.
  • Aikouka - Thursday, February 1, 2007 - link

    I have to say, LoneWolf, that I agree with you when it comes to IE7 on Windows XP. I installed it and it simply didn't fit at all. Although, for some reason, IE7 doesn't seem weird on Vista at all. It's probably because of how Windows Explorer also looks the same (lack of a menu bar).

    Also to go along with LoneWolf, I have had no issues with Firefox (2.0.0.1) in Vista so far :).
  • Spacecomber - Thursday, February 1, 2007 - link

    I didn't see this covered in my first pass through this article, but I was interested in learning more about the potential impact of MS's new Universal Audio Architecture on gaming performance, which I recently saw covered in a http://www.dailytech.com/Underneath+Microsofts+Uni...">DailyTech news item.
  • quanta - Friday, February 2, 2007 - link

    There is NO performance to speak of, because Vista does not support hardware DirectSound acceleration. Alchemy only works on X-Fi, so anything older is useless.
  • Cygni - Thursday, February 1, 2007 - link

    One thing ive really been wondering about is what MCE is like in Vista? The article briefly mentioned TV Tuner support worked fine, but was MCE tried? Was it different? How was its performance under Vista? For me, thats the deciding factor.
  • Anand Lal Shimpi - Thursday, February 1, 2007 - link

    I'll be doing a look at MCE in Vista as soon as we get a system in house with the ATI TV Wonder Digital Cable Tuner (formerly known as OCUR). I'm hoping that this will happen in the coming weeks.

    Take care,
    Anand
  • Aikouka - Thursday, February 1, 2007 - link

    Anand, doesn't that digital tuner require some special sort of hardware to run? I believe I remember a thread on the forums (under Video if I remember correctly) that discussed how it won't run on every system regardless of how powerful they are.

    One thing I'm curious of... does Windows Vista's MC application have the same tuner restrictions as MCE's MC application? Because I originally purchased a TV Wonder Pro awhile back for normal use, and now it sits in my MCE machine dormant, because MCE doesn't support it (although open source MC-esque applications do). If it weren't for the nice ATi RF remote, I probably would've sold it already for one that works in MCE :P.
  • Ryan Smith - Thursday, February 1, 2007 - link

    To be honest, I have never more than glanced at MCE, as I don't have a HTPC to make much use of it. I could tell you a bit about it, but I'm not really qualified to go in-depth about it, so we left it out.
  • Myrandex - Thursday, February 1, 2007 - link

    same here too. I used to run XP64 full time but then switched to MCE for the MCE app. I am really interested in Vista x64 with MCE and I would have loved to see something about it.
  • ATWindsor - Thursday, February 1, 2007 - link

    I really hope there is som driver-issue that explains the poor network-performance in this test, XP is already pretty bad in this regard, one of the big things with Vista is that the network performance should be better.

    And furthermore i have two questions: The search, does it support network-drives? Search Desktop for XP does not...

    Is there software raid-5 support in Vista?

    A few disappointing things with Vista:
    - Still the 255-charachter-limit, that is really annoying.
    - Still an enormously primitive file-copying-application. This is basic important stuff that should be better.

    AtW

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