Is there a guide on the metrics required to obtain a certain Windows Experience Index?

A Microsoft guy said in January 2009:

On the matter of transparency, it is indeed our plan to disclose in great detail how the scores are calculated, what the tests attempt to measure, why, and how they map to realistic scenarios and usage patterns.

Has that amount of transparency happened? Is there a technet article somewhere?

If my score was limited by my Memory subscore of 5.9. A nieve person would suggest:

Buy a faster RAM

Which is wrong of course.

From the Windows help:

If your computer has a 64-bit central processing unit (CPU) and 4 gigabytes (GB) or less random access memory (RAM), then the Memory (RAM) subscore for your computer will have a maximum of 5.9.

You can buy the fastest, overclocked, liquid-cooled, DDR5 RAM on the planet; you'll still have a maximum Memory subscore of 5.9.

So in general the knee-jerk advice "buy better stuff" is not helpful. What i am looking for is attributes required to achieve a certain score, or move beyond a current limitation.

The information i've been able to compile so far, chiefly from 3 Windows blog entries, and an article:

Memory subscore

Score    Conditions
=======  ================================
1.0      < 256 MB
2.0      < 500 MB
2.9      <= 512 MB
3.5      < 704 MB 
3.9      < 944 MB 
4.5      <= 1.5 GB
5.9      < 4.0GB-64MB on a 64-bit OS
         Windows Vista highest score
7.9      Windows 7 highest score

Graphics Subscore

Score    Conditions
=======  ======================
1.0      doesn't support DX9
1.9      doesn't support WDDM
4.9      does not support Pixel Shader 3.0
5.9      doesn't support DX10 or WDDM1.1
         Windows Vista highest score
7.9      Windows 7 highest score

Gaming graphics subscore

Score    Result
=======  =============================
1.0      doesn't support D3D
2.0      supports D3D9, DX9 and WDDM
5.9      doesn't support DX10 or WDDM1.1
         Windows Vista highest score
6.0-6.9  good framerates (e.g. 40-50fps) at normal resoltuions (e.g. 1280x1024)
7.0-7.9  even higher framerates at even higher resolutions
7.9      Windows 7 highest score

Processor subscore

Score    Conditions
=======  ==========================================================================
5.9      Windows Vista highest score
6.0-6.9  many quad core processors will be able to score in the high 6 low 7 ranges
7.0+     many quad core processors will be able to score in the high 6 low 7 ranges
7.9      8-core systems will be able to approach 8.9
         Windows 7 highest score

Primary hard disk subscore (note)

Score    Conditions
=======  ========================================
1.9      Limit for pathological drives that stop responding when pending writes
2.0      Limit for pathological drives that stop responding when pending writes
2.9      Limit for pathological drives that stop responding when pending writes
3.0      Limit for pathological drives that stop responding when pending writes
5.9      highest you're likely to see without SSD
         Windows Vista highest score
7.9      Windows 7 highest score

Bonus Chatter

You can find your WEI detailed test results in:

C:\Windows\Performance\WinSAT\DataStore

e.g.

2011-11-06 01.00.19.482 Disk.Assessment (Recent).WinSAT.xml

<WinSAT>
   <WinSPR>
      <DiskScore>5.9</DiskScore>
   </WinSPR>
   <Metrics>
      <DiskMetrics>
         <AvgThroughput units="MB/s" score="6.4" ioSize="65536" kind="Sequential Read">89.95188</AvgThroughput>
         <AvgThroughput units="MB/s" score="4.0" ioSize="16384" kind="Random Read">1.58000</AvgThroughput>
         <Responsiveness Reason="UnableToAssess" Kind="Cap">TRUE</Responsiveness>
      </DiskMetrics>
   </Metrics>
</WinSAT>

Pre-emptive snarky comment: "WEI is useless, it has no relation to reality"

Fine, how do i increase my hard-drive's random I/O throughput?

Update - Amount of memory limits rating

Some people don't believe Microsoft's statement that having less than 4GB of RAM on a 64-bit edition of Windows doesn't limit the rating to 5.9:

And from xxx.Formal.Assessment (Recent).WinSAT.xml:

<WinSPR>
  <LimitsApplied>
    <MemoryScore>
      <LimitApplied 
          Friendly="Physical memory available to the OS is less than 4.0GB-64MB on a 64-bit OS : limit mem score to 5.9" 
          Relation="LT">4227858432</LimitApplied>
      </MemoryScore>
    </LimitsApplied>
  </WinSPR>

References

• Windows Vista Team Blog: Windows Experience Index: An In-Depth Look
• Understand and improve your computer's performance in Windows Vista
• Engineering Windows 7 Blog: Engineering the Windows 7 “Windows Experience Index”