How does the performance rating work?

How does the performance rating work?

Summary: From Ed's mailbag: When you install Windows Vista, it runs a System Assessment Tool and gives your computer a performance rating called the Windows Experience Index. What does that number mean? What kind of hardware gets a perfect score

TOPICS: Windows

I've been getting great questions about Windows Vista via e-mail lately and thought I would answer a few of them here. If I keep getting good questions, I'll make this a regular feature.

Yesterday, Stefan asked about the "Windows Vista System Performance Grade":

I don't understand the scale really. How it works, what a 1 is, what a 10 is, and I can't find information on these topics ... It's frustrating.

Can you possibly send some links my way, or find out, how the hell in the world this scaling system works and what it would take to get a perfect score (whatever that number might be?)

The Windows Vista System Assessment Tool runs at installation time (and later, if you change hardware) and produces an overall rating of your hardware called the Windows Experience Index. In August, my ZDNet colleague Adrian Kingsley-Hughes put together a really great, in-depth look at the Windows Experience Index based on an earlier beta release. Adrian’s post is a good companion to Vista Mythbusters #1: It’s not a hardware hog.

The most definitive explanation I've seen so far is Windows Experience Index: An In-Depth Look, on the Windows Vista Team Blog. It explains what goes into the 5 sub-scores, each of which can range from 1 to 5.9 (higher is better). The lowest of the sub-scores becomes the base score. So the system whose index is shown here has a smokin' hard disk, fast RAM, and a decent CPU, so it gets scores of 5.1 or better in all those categories. But the video card in that same machine was a low-cost add-in and it shows, with Graphics and Gaming Graphics scores of 3.9 and 3.7, respectively. That last number is the one that appears in big bold type in the Welcome Center.

Windows Experience Index

No, you can't score a perfect 10 yet. The top rating is 5.9. But maybe someday:

Over time, we expect to introduce higher scale levels of 6 and beyond. This will be done approximately every 12-18 months, as new innovations in hardware become available. When new base scores are introduced, existing scores will not change (i.e. a PC with a base scored of 2.2 today will score a 2.2 in the new updated index, unless its components are upgraded).

In this thread at, a group of Vista beta users have been posting details of their Experience Index scores. An NVidia GeForce 7900 GT/GTO with 527MB of graphics memory earned perfect video scores in, while a similar NVidia GeForce 7900 GS and a Radeon X1900 with more than 1GB of graphics RAM both earned a perfect 5.9 for Graphics and a so-close-but-not-quite 5.8 rating for Gaming Graphics.

An Intel Core 2 6600 CPU at 2.4GHz gets a 5.8; an older 3.2GHz Pentium 4 earns a 4.3. My SATA-300 controller with a 7200RPM hard drive and large cache gets a 5.5. If you're interested in learning how to pick components that will get a perfect score, this thread is worth scrolling through.

If you have any Windows Vista questions,click the e-mail link on my bio page and send them to me. I can't promise to reply personally or on this site, but I do read every one. Be sure to include your e-mail address (I won't share it with anyone and won't use it for anything except to contact you with answers or questions of my own.)

Topic: Windows

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  • Good Article on a Tough Subject.

    The truth information and is there is not a lot of solid the scale has slid arrouned from build to build as different constituents weighed in. The most noticeable was Intel's complaint that it didn't place enough value on the CPU. People should realize this is a guideline to evaluate what software will run on the machine. If the software providers go along there will be a rating on the box that shows the minimum rating required to adequately run that package. It is sure better and less confusing the the laundry list of specifications they must compare now!
  • What a great way for geeks

    to compete for highest score.

    I want to know how these quasi-quantitative scores relate to the actual computer's performance. Is there any way to relate this numeric to how well the bloody thing will work? Is there any way to compare the score to how my computer performs with XP? Does the performance score take into account the latency or quality of the driver or does it just look at the device's size/speed/ram numbers? Yes I read the very vague blog from the Windows Experience Index and it's not too helpful. Memory badwidth? Is that for 1k, 2k, 16k, 32k, etc. blocks? Hard drive speed? Does that include seek time, latency, large block (exceeding the disk's buffer)? I can understand a crude set of levels from 1 to 5, but the decimal points seem like the meat and bones of specmanship.

    At the decimal point level, I doubt that there is really no way to meaningfully compare the score to the subjective feeling of how a given box will work so it seems like just a "braggin' rights" kind of thing.
    • Well, I just wanna know if it will impress the ladies.

      I've been a Linux geek since '95 and my last date was sometime shortly before that. So will switching to Vista, and getting a high performance score, help me meet women?
      • Yeah, but

        you won't to meet those ladies...

        The sexy babes prefer OSX men.
    • The first draft of this post...

      ...contained the following line:

      "In this thread at, a group of Vista beta users have been comparing Experience Index scores to see who has the biggest one."

      I reluctantly decided to rewrite that sentence.

      I wish the Windows Vista team would document these tests more fully. I agree that the brief discussion on the WVTeam Blog is pretty weak, but I think that's all we're going to get.
      Ed Bott
  • Do we need Vista for this?

    Correct me if I'm wrong, but it looks like you need Vista already installed for this?

    Would it be too much to ask to add this to the upgrade advisor?
    • Yes, you need Vista for this

      It would be nice for someone to see this info before they upgrade, I agree.
      Ed Bott
  • Good article!

    Hello from Poland,

    This article is very good!
    Thanks for this article.

  • Message has been deleted.