I’m getting confused with Windows 7 experience index; because on one of my home computers with 2 hard disks 7200 rpm configured with RAID 0 I got 5.9 as score on “ Disk data transfer rate “, while on another computer which had only one hard disk 7200 rpm got also 5.9 as score on “ disk data transfer rate “.

Shouldn’t RAID 0 configuration means high read write IO?

  • a pair of Intel 80gb X25s in raid0 is 7.9 (Windows 7 64x; I7-960 Sager NP9280 laptop; 6Gb RAM) – user41053 Jun 26 '10 at 0:34

While there is a slight performance increase in RAID-0 for home users, it is not as drastic as many would have you believe. RAID-0 was designed with a multi-user server scenario in mind with multiple random reads and writes at once. Many of the RAID benchmarks are using this scenario, and not a single-user scenario that accurately represents home users. This doesn't explain why they are identical in the Windows benchmark, but in reality, the performance is relatively close.

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    I think it's important to add that random reads/writes must be <= the stripe size for RAID 0 drives to be able to operate independently - and for there to be any benefit to the random read/write performance (compared to a single drive). So this will probably tend to be the case for a server performing many small database queries/updates. – sblair Aug 15 '10 at 22:18
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    As seek speed is not increased with RAID-0, it is sustained throughput which benefits from it, like when reading very large continuous files - eg. video editing. – paradroid Nov 8 '10 at 20:27

According to this thread on Tom's Hardware, and this one on win7 forums, 5.9 is the maximum rating for a mechanical hard drive, e.g. anything prior to solid state drives (SSD).


I have the same problem. My RAID0 setup (2 Western Digital 7200RPM) rates 5.9. Basically you need to use hard drives with higher RPMs or use SSDs.

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    +1. A good SSD trounces standard hard drives in raid0. 2 10,000rpm raptors in raid0 isn't as good as crucial c300. – RJFalconer Nov 8 '10 at 20:04

The Windows Experience Index is a simple metric to indicate performance. Sure, you will have decent read performance under RAID 0, but write performance will be less than more high-end drive. Clearly you'd expect RAID 0 to measure slightly better, but this is only a crude metric.

My Samsung F3s get 5.9 under AHCI, and 5.9 under RAID. Another machine with 15,000 rpm SAS drives only get 6.3.

I'm not sure even the best SSDs will rate 7.9...yet...


I don't think there's a way to statically improve HD performance in WEI. I had a 320GB 7200RPM in my laptop with a 5.7 rating. I switched to a 128GB SSD and the rating jumped to 7.1 (the total rate remained the same, since it's dictated by the lowest score).

protected by studiohack May 3 '11 at 10:15

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