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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  • Ryan Smith - Saturday, February 3, 2007 - link

    That's up to Vista, it benchmarks a flash drive to make sure it's fast enough to be effectively used as a ReadyBoost cache. If ReadyBoost won't engage, then your drive isn't passing one(or more) of their tests.
  • mlambert890 - Friday, February 2, 2007 - link

    How is the PC hemmhoraging marketshare to the Mac? You've got to be kidding. Their marketshare in 06 rose from a pathetic 4.4 to a somewhat less pathetic 4.8. Thats with ALL of their ridiculous hype, ALL of the asskissing from the press (including you guys now I guess?) and ALL of the armies of lunatic "Mac priests" that pollute every forum.

    Its hillarious that you would position this tiny growth in a share that declined steadily for 22 years until it hit rock bottom at like 3% in 2003 as a "hemmhorage". I have to wonder why you would characterize it that way. To be honest, it reeks of bias.
  • quanta - Friday, February 2, 2007 - link

    Think about it, ReadyBoost is treated by Vista as random access memory, to store temoprary contents than can change very often. Considering typical USB flash drive only has 100k write cycle, you will need to replace it very soon. Worse yet, when the flash drive is gone, so will your critical data at the worst possible time. With the hardware requirement of Vista, no amount of wear levelling is going to help.
  • Ryan Smith - Friday, February 2, 2007 - link

    No, this is wrong.

    ReadyBoost is a write-through data cache handled by the SuperFetch system; when enabled SuperFetch uses it as another cache location optimized for small files. Based on the information we've seen, it's used primarily to store DLLs and other static and semi-static data that is needed an intermediate amount of time(not important enough to spend valuable RAM, important enough to cache), with highly dynamic data sent to SuperFetch or the hard disk to avoid unnecessary wear out. It will most certainly put wear on flash memory, but it seems unlikely that it will put 51TB of write-wear(the amount of data that needs to be written on a 512MB flash card to write over all bits 100k times) before several years out.

    Of course, this is as according to Microsoft. We don't really know what exactly is being stored on a ReadyBoost drive at any given moment, however we have no reason to believe that Microsoft isn't really taking efforts to minimize writes. We'll find out if/when flash memory starts wearing out.
  • mlambert890 - Friday, February 2, 2007 - link

    We'll see. Please remember that the 100k write cycle is an average, that the flash is used as a small cache only, and that write leveling of COURSE will help before making assumptions.

    Ive been beating up flash for YEARS thats still going. There are moves to literally put OS's on flash based hard drives. Hybrid drives already use the same concept as ReadyBoost (and are also supported on Vista).

    Using flash as a cache for magnetic media is not some untested concept that is going to lead to global data destruction.

    MS must have really destroyed their mindshare that so many armchair scientists are just fully willing to believe that theyve figured out ALL the stuff that the "idiots" in Redmond dont realize. Give a little credit to the armies of PhDs that work on at least the basic concept for this crap. Maybe implementation gets flawed by the realities of release cycles and budgets, but BASIC CONCEPT is typically sound.
  • dugbug - Friday, February 2, 2007 - link

    UAC is like a firewall -- chatty at first (during installs and configurations), but once you have set up your system you will hardly ever hear from it. This should be obvious to the authors.

    And for that matter, the 6-operation file delete they discuss in the beginning was for deleting a file on a shared desktop (meaning a delete was for all users). This is commonplace for enterprise and workplace users, it should be no surprise that a file used by others would require permissions to delete. Though Im glad the number of operations was greatly reduced.

    As to the comments about vista being sluggish? Perhaps it is RAM? I have 2Gb and vista runs without any slowdown at all. Once you use it for a while you won't go back to XP.

    -d
  • LoneWolf15 - Friday, February 2, 2007 - link

    Untrue. Enthusiasts use lots of things like the Control Panel, MMC console, etc. and these all require UAC every time. Currently, I also have startup programs on my beta-test box that UAC blocks. This would be fine, if UAC had a feature saying "Yes, I know what this program is, let it run every time all the time" and be done. But, UAC doesn't have this option, so a user has to allow the program to run every single freaking time they boot their machine.

    I've tried changing the program properties so that it runs as Administrator; that hasn't solved the problem. I turned off UAC, which gives me a lovely annoying red-X shield in the system tray that every so often decides to warn me with a popup balloon that UAC is turned off and I could be in danger, so it's annoying even when turned off, and there's no easy way around it. Enthusiasts do a lot with their computers, and what they do is likely to increase their number of UAC prompts. Bottom line: Unlike OS X's methods, Vista's UAC happens far more often, and is far more annoying. And because it doesn't require a password (like OS X) and is just a click-through, I'll put money down that within a year, it will be worthless, as the average user will learn to click through it without reading a single bit of info.
  • funk3y - Sunday, February 4, 2007 - link

    The red cross can also be disabled for sure; on my computer, which is a member of a domain I recieve no error message at all, even if UAC & co are disabled.
  • haplo602 - Friday, February 2, 2007 - link

    Realy. What's the hype all about ?

    SuperFetch - trivial change to caching mechanisms. Anybody that would require it would have already implemented it in *NIX systems. This is a purely desktop user feature to hid some processing overhead. There's nothing new about this that would prevent implementation in w2k already except MS incompetence ...

    ReadyBoost - So the new standard is to have a permanently attached USB stick to have some performance ?

    Compund TCP, Receive window auto tuning - I laughed like mad. So they finaly made a proper implementation of something network related? End even then Vista is SLOWER. I'd suggest take a stand-alone NIC that Vista nad XP have drivers for themselves and test it. Should rule out driver bugs.

    I/O improvements - so I make an app that makes a high priority high capacity I/O operation (say 1GB) and you can go for lunch till the system is anyway usable. Seriously. I/O in small chunks makes perfect sense in multitasking environments since you have more entry point and can adjust the stream on OS level and tune performance. That XP or Vista are stupid enough to do this is their fault. I guess MS will hype this as the next best thing in a future OS ?

    All in All every feature hyped in the article does not deserve a Marketing Name(tm) because it is a normal concept. So we have a shiny new bigger and slower OS that is hiding this behind hyped features. F.E. memory compression could very much improve system performance without relying on external devices (ReadyBoost).
  • mlambert890 - Friday, February 2, 2007 - link

    Just admit your bias man. There is NOTHING MS could do that would cause you to give them kudos. I spend my days arguing with guys like you for a living (unfortunately) and its just exhausting.

    I could point you to REAMS of documentation of all the crap that has been rewritten and overhauled in Vista, but whats the point? You want to hate it so hate it.

    Its sad that technology debates are STILL religion for so many after all this time :(

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