Memory in Vista: How much do you need?

Meeting with memory makers has been fun these past several months - they're all so happy. It's a stressful business, but these days the memory makers are quite excited about Vista and after using the OS for a while now we can understand why. You've undoubtedly been hearing that Vista's memory requirements will be greater than those of XP, but how much greater are they in practice and why?

First and foremost, Vista's memory requirements are higher than XP's simply because there is much more to Vista than XP. There are far more background tasks to take care of, a much more complex UI, and a code base that's significantly larger than that of Windows XP. All of these items require memory, and thus when you boot up a Vista machine with 512MB of memory, almost all of it is already being used.

Microsoft and software makers in general are notoriously bad about understating minimum system requirements, so when you see that the bare minimum requirements for Windows Vista list a system with 512MB of memory, you should know right off the bat that this isn't going to be a pleasant experience. Although Vista will do its best to disable background tasks and neat effects to make using your computer less painful with 512MB, we simply wouldn't recommend it. You can get by running a single application, such as IE7 or Outlook, but multitasking is out of the question. In one of our test scenarios we had four applications open and attempted to close one of them. This process took around 2 seconds if we had 2GB in the system, but it took over 12 seconds if we only had 512MB. Most of us really don't like using Windows XP on a system with only 512MB, and needless to say Windows Vista turns that dislike into outright hatred. Windows XP is more tolerable with 512MB, but we would make a very similar characterization about the overall experience on a system with such little memory.

The experience completely changes with 1GB; the improvement is tremendous. Searches appear quicker, applications launch and close faster, and using the OS is just so much better. Once again, we're not telling you anything you haven't heard before, except that 1GB should really be the minimum for any Vista machine and not just those that are Premium certified. Even our budget Buyer's Guides have recommended at least 1GB of RAM for over a year, and Vista pretty much makes that a requirement.

It's the above-1GB range that really has most of us concerned. For the longest time, 1GB was sufficient for most enthusiasts under XP. As applications and usage models got more demanding, and as memory prices dropped, the move to 2GB made sense. Above and beyond 2GB never really made a lot of sense because Windows XP didn't seem to do much with the added memory. Even if you had unused memory, Windows XP didn't really make the most of it resulting in even recently used programs being paged in from disk instead of loaded out of the main memory cache. Vista changes all of this.

If your memory usage under XP kept you just under needing more than 2GB, you'll need 2GB with Vista. We took two identical installs, one with Windows XP and one with Vista, both equipped with 2GB of memory and ran the following scenario on them:

We opened 104 images in Adobe Photoshop CS3 from our recent trip to Las Vegas for CES 2007; with all 104 images opened and loaded, we then timed how long it would take for Microsoft Word to start. In Windows XP, despite some swapping, Microsoft Word 2007 started in just under 8 seconds. On our Vista test bed, starting Word took almost 20 seconds due to constant paging to disk. The only difference? Vista's heightened memory requirements took a stressful situation that worked reasonably well under XP and made it far more painful with the same amount of memory.

We then upgraded the Vista machine to 3GB and ran the test again; thanks to faster application load times and intelligent prefetching, Word started in 1.31 seconds. If you thought that 2GB was the sweet spot for Windows XP, chances are 3GB will be the new minimum for you under Vista.

Thus far all we've talked about, at a high level at least, are static memory requirements and how they are impacted by Vista. Vista uses more memory and in turn, you'll need a bit more memory to get a similar experience to what you had under XP. With SuperFetch however, Vista can actually significantly improve your system's performance if you throw more memory at it.

New I/O Features SuperFetch Performance Analysis
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  • nishzone - Saturday, May 24, 2008 - link

    Hi,

    I'm glad tnat your memory usage is similar to mine and therefore I might finally understand this. You have 2 gig of Ram...I understand that superfetch is the reason free ram is 0 (cache increases as free memory decreases). But why is the memory usage 45%? so around 1 gig?

    I also have 50% usage on startup. Is vista using 1 gig memory? There is something I don't understand here because you recommended 1 gig for general users.

    Regards,
    Nishzone
    Reply
  • Dataland - Wednesday, November 28, 2007 - link

    I think Microsoft needs a performance reset. As I've said in some previous posts, I think software in general, and Microsoft software in particular, is getting slower at faster rate than hardware is getting faster. And this problem acutely affects Vista. I think Microsoft needs... (Pingback)

    Performance Reset
    http://dataland.wordpress.com/2007/11/28/performan...">http://dataland.wordpress.com/2007/11/28/performan...
    Reply
  • Kondado - Saturday, February 10, 2007 - link

    I've done my own tests. I sent the same amount of data (51 files, 2,5 GB) once from XP to Samba, then from Vista to Samba (OpenBSD). Then I did the same from XP to XP, and from Vista to XP. XP was always a LOT faster.

    I would really know if it's the drivers or the stack...
    Reply
  • jonp - Monday, February 05, 2007 - link

    It seems like the budget system area was a little overlooked in this review of Vista. So I have some questions:

    "Memory in Vista..." - It appears that acceptable multitasking performance is found somewhere in the 3GB to 4GB memory size area. Many budget systems have only two memory slots and many new ones support dual memory access. This will force budget systems to 4GB which is fairly pricey now and probably will be for some time.

    "CPU Performance..." - Your love for anything Core2 Duo shines here. But what about the dual core Pentium Ds? Like the D915 2.8GHz processor. Yes it is Netburst, but also easier on the budget than a Core 2 Duo processor. We need something more specific here in terms of benchmarks/guidelines.

    Video adapters - I didn't see anything that talked about integrated video adapters vs. VGA/PCIe video adapters. Are any of the integrated graphic engines, like Intel 950GMA provide acceptable performance for VISTA? How about older video cards? Minimum graphics memory? Graphics engine speed? Again we need more specific guidance here.

    Hard drive - You addressed hard drive performance, in a way, in the "Vista Search for Fast Drives Only" section. But again no specific device selection guidelines like: RPM, cache size, average access, size, data transfer rate, ...

    Virtualization - It appears that MS forbids the use of virtualization products with Vista Home Basic and Home Premium editions forcing budget users to more costly editions of Vista.

    Upgrade or "clean" install? - Not strictly a budget system issue; the web if full of warnings about NOT trying to upgrade to Vista --- that it should only be a "clean" install situation. That upgrading is fraught with too many pitfalls that it isn't even worth trying. And not all editions of Vista are allowed to do in-place upgrades of the XP editions; oh, and you can't do an in-place upgrade of anything prior to XP. See http://tinyurl.com/36ljxv">http://tinyurl.com/36ljxv for some upgrade details.
    Reply
  • JarredWalton - Monday, February 05, 2007 - link

    quote:

    Even with a lengthy preview article, there is still a lot of ground to cover when taking a close look at the final release version of Windows Vista. We have attempted to create a comprehensive look at the new operating system, but even then there are still plenty of items that will have to wait for another day before we can truly evaluate them.


    Basically, a lot of that falls into areas we are going to look at in future articles. Given that we don't really recommend most people upgrade to Vista yet, the lower-end your system is the less we would consider Vista. Pretty much all of the DX9 NVIDIA and AMD cards do fine with the Vista Aero Glass UI, but IGP solutions are slower. Individual tolerance for the UI will vary; I'm sure plenty will be okay with GMA950 and Glass, while others won't want anything less than a $100 discrete GPU. Oh, and GPU drivers for Vista are still flaky, IMO. :)

    HDD, anything 7200 RPM should be fine. CPU, really with a decent GPU the requirements aren't all that much higher than XP. RAM is more important - don't even think about Vista with less than 1GB - but HDD and CPU most people with anything made in the past two years will be fine. Just my opinion there - individual usage and preferences will again play a role.

    I wouldn't say 3-4GB of RAM is even remotely necessary for most people. A few will like it, but 2GB is still sufficient for about 99% of people.

    Virtualization and Upgrades... I'll have to defer to others there. Again, I recommend discretion, so I would tend towards doing a full backup (Ghost or similar) of any system before doing a Vista upgrade. I believe Gary is about to revert his system for the time being, as Vista has just had a few too many glitches. The number of people that worry about virtualization - really intending to use it, not just for test purposes - is again very small. I think mostly we're seeing the vocal minority complaining. Still, I find it odd that MS even worries about whether or not people run the OS via virtualization - unless the glitches are aggravated by such an environment, which is entirely possible.
    Reply
  • jonp - Tuesday, February 06, 2007 - link

    Thanks Jarred...you insights are always very helpful and I am glad that these topics will get more focus in the future. Jon Reply
  • jonp - Monday, February 05, 2007 - link

    Both of the charts in the Compound TCP section for Windows Vista say "Compact" and not "Compound". Reply
  • duploxxx - Sunday, February 04, 2007 - link

    Its probably me that's missing a page or so but could you guys explain what system you used for these tests? Reply
  • funk3y - Saturday, February 03, 2007 - link

    Hello

    I also spent some time testing the network part of windows vista, and I discovered some quite interesting things:

    Windows Vista is reducing the network I/O when an application using the audio interface is launched, I discovered this when copying large files over my network.

    When I copy large file through the network the average speed is 40 mb/sec and the taskmanager whow 30-50% of network use, as soon as I start an application playing sound (WMP, Skype, Warcraft III, ....) the rate drop to 8 mb/sec and the network use in the taskmanager never go beyond 12.5%

    I achieved those test on different hardware, with differents drivers and the results are always the same; it is just impossible to get further then 12.5% of network use while playing a sound.

    My guesses are that microsoft voluntary did this, in order to avoid sound crackling. Because of the new driver scheme, bad written drivers having to do many I/O could lead to sound degradation (I had this issue while using my raptors RAID on a NF4 board; making a lot of I/O on the disk just killed the sound quality).

    As you where streaming a film while benchmarking, you may have been in this situation. It could be nice if you could rerun some benchmark taking into account all what I have written.

    As I am already posting, here are some other consideration about DOS and vista:
    -It is just impossible to launch a DOS application in fullscreen mode! This functionnality lack can be really painfull in environnement where DOS application are still well used; I just don't understand microsoft's choice
    -I don't think that vista x64 is still able to launch 16 bit apps anymore (keep this in mind before upgrading to x64!)
    Reply
  • ministerchief - Saturday, February 03, 2007 - link

    I have a "Corsair Flash Voyager 4Gb" usb stick and I can't use it to "BOOST" my system.

    So, how anandtech could use it ?

    Can someone tell me how to use this flash drive with the "READY BOOST" feature.


    THX
    Reply

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