Haydentech
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Precision T1700 with Intel RAID - RAID degrades over & over

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I just added a 2-drive RAID mirror to my Precision T1700 using the built-in Intel RAID option.  I'm able to create the mirror fine in the RAID BIOS, and also create the NTFS drive from the mirror when I boot to Windows.

For some reason, within a matter of minutes, one or even both of the drives show as degraded in the mirror.  There is no indication of a real problem, they just seem to come and go seemingly at random.  Sometimes I'll reboot and they'll both be "normal", sometime both will be degraded, sometimes one or the other will be degraded.  When I mark a degraded drive as "normal" in IRST, the mirror successfully rebuilds, which takes about 8 hours (!).  Then within minutes of finishing the rebuild, the array degrades again and I'm back to square one.

What's going on here, and how can I fix it?

 

Precision T1700, Bios A25

Windows 7 Pro x64, fully updated

Latest Intel RST software supported by this BIOS (14.8.16.1063)

2x Seagate Constellation 3TB enterprise-class drives (MB3000ECWCT) in RAID 0

 

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bmcowboy
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Re: Precision T1700 with Intel RAID - RAID degrades over &am

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Hi @Haydentech ,

Intel IRST on-board RAID performance may somehow limited to motherboard cache and hard drive cache settings. If you're using the added drives as data drive but not for OS, you may try assigning them as normal drive (i.e. non-RAID) and create a software RAID inside Windows 7. Here's an article regarding how to create a software RAID in Win7.

“May the Force be with Dell.”
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XeonForever
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Re: Precision T1700 with Intel RAID - RAID degrades over &am

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Hello. I think that is a SATA cable problem. Try to change them for 2 brand new cable. I had the same problem with my old T1600. Actually one of them had failure. 

If this is not solved the problem then try to run a full diagnostic from the bios.

Precision T3600 E5-1660 32GB GF 980 128GB+4TB
Precision T3600 E5-1620 12GB GF 960 128gB+1TB
Precision T1600 E3-1225 8GB MATROX512MB WD Raptor149GB/Raid
Haydentech
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Re: Precision T1700 with Intel RAID - RAID degrades over &am

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I believe that the cables played a part.  I swapped them for a different set of cables and the array dropouts became less frequent -- about once a day or so.

Then I did what I should have done from the start.  I spend a measly $35 and bought a MegaRAID PCI-e card and SAS->SATA cabling.  Now, using the same disks, I have no dropped arrays and my throughput speeds are anywhere from 33% to 500% faster depending on the workload:

Before (with Intel RAID):

  Sequential Read (Q= 32,T= 1) : 167.583 MB/s
 Sequential Write (Q= 32,T= 1) : 166.821 MB/s
  Random Read 4KiB (Q= 8,T= 8) : 4.800 MB/s [ 1171.9 IOPS]
 Random Write 4KiB (Q= 8,T= 8) : 1.302 MB/s [ 317.9 IOPS]
 Random Read 4KiB (Q= 32,T= 1) : 4.793 MB/s [ 1170.2 IOPS]
Random Write 4KiB (Q= 32,T= 1) : 1.329 MB/s [ 324.5 IOPS]
  Random Read 4KiB (Q= 1,T= 1) : 1.452 MB/s [ 354.5 IOPS]
 Random Write 4KiB (Q= 1,T= 1) : 1.349 MB/s [ 329.3 IOPS]

After (with MegaRAID card):

  Sequential Read (Q= 32,T= 1) : 255.039 MB/s
 Sequential Write (Q= 32,T= 1) : 206.180 MB/s
  Random Read 4KiB (Q= 8,T= 8) : 6.794 MB/s [ 1658.7 IOPS]
 Random Write 4KiB (Q= 8,T= 8) : 6.281 MB/s [ 1533.4 IOPS]
 Random Read 4KiB (Q= 32,T= 1) : 6.109 MB/s [ 1491.5 IOPS]
Random Write 4KiB (Q= 32,T= 1) : 6.369 MB/s [ 1554.9 IOPS]
  Random Read 4KiB (Q= 1,T= 1) : 1.292 MB/s [ 315.4 IOPS]
 Random Write 4KiB (Q= 1,T= 1) : 6.312 MB/s [ 1541.0 IOPS]

So the answer is that Intel RAID makes no sense, even in a consumer-level scenario like mine.  Don't waste your time with it.