What happened to my computer’s rating in Windows 7?

I got a frantic call from a friend this morning.  ‘I installed Windows 7 last night; When I checked my System Rating the Windows Experience Index was 5.9, and now it’s only 4.1!  Why is my system slower?’

This is not the first time I have gotten this question, and indeed noticed the same thing when I first installed Windows 7.  Let me reassure you that your computer has not lost any of its oomph… in fact, it will have gained some, as Windows 7 is a more efficient OS than Vista, with a smaller footprint.

Firstly let me say a quick word on the Windows Experience Index.  Windows rates five key components in your computer that combine to determine your system’s performance, which are Processor, Memory, Graphics, Gaming graphics, and Primary hard disk.  It assigns each a subscore between 1.0 and 7.9.  The lowest of these scores is your computer’s Windows Experience Index.  It does not mean that your computer will not perform well with a low score; the CPU and RAM on my laptop are rated 6.5 each, but the Graphics is a 4.3; Most of what I do that requires high performance is not video-intensive, so the lower subscore and consequent System Rating does not really affect me.  If I were to resell my laptop to someone whose main interest is playing video games then they would probably think twice before buying it.

The only constant in the world of computers is that hardware gets better.  Gordon Moore predicted in 1965 that “The number of transistors and resistors on a chip doubles every 18 months.”  Ten years later he extended it to 24 months, but Moore’s Law has been remarkably accurate.  Essentially what this means is that computers are MUCH faster now than they were 40 years ago… or 2 years ago.  (to show how far we have really come, in 1965 there were about 60 transistors and resistors on a chip; Intel’s Itanium processor currently has in excess of 1,700,000,000 transistors)

All this to say that our computer components get faster.  Rather than Windows 7 increasing the upper limit rating from 7.9 to 12.9, they have moved the bar without moving the goalposts; that is, your hard drive that used to have a 5.5 rating may now have a 3.5 rating, to make way at the top end for newer, higher-performance drives.

What does all of this mean to your system’s performance?  Nothing.  It will not run slower because its rating has been lowered… in fact because of the improvements to the way Windows works it will actually run better; it will simply have a lower rating… to which we ask the question: So?  I drive my car at 110km/h on the highway; when I drive in the US I have to switch from metric to Imperial, so I am now driving 70mph… am I driving any slower?  No, just measuring the speed differently.  However since the Interstate highways in the US are better roads than the highways in Canada (well, not in Michigan…) I will have a more pleasant, quieter ride.  It’s the same with your computer… same system, better and smoother ride.  Enjoy it!

For more information about the Windows Springboard Series visit http://go.microsoft.com/?linkid=8418918.

Read the complete post at http://mitchgarvis.com/blogs/mitch/archive/2009/06/18/what-happened-to-my-computer-s-rating-in-windows-7.aspx