RAID50 slow speed

George Alexandov
George Alexandov used Ask the Experts™
My Problem is RAID50 slow speed.

Initial RAID Configuration:

  • Disk Drives: 6 HDD TOSHIBA MBF2600RC (600 Gb, 16 Mb, 10025 RPM, SAS, 600 Mb/s)
  • 2 Spans
  • Motherboard: SuperMicro X8DTU-6F+/6TF
  • RAID Controller: SuperMicro SMC2108
  • Virtual Group: RAID50
  • Polices:
    1. Access: RW
    2. Read: Normal
    3. Disk Cache: Enable
    4. I/O: Cached
    5. Disable BGI: NO
    6. Default Write: Write Through
    7. Used Operation System: Windows Server 2016


CrystalDiskMark Metrics:
Read [MB/s]: 221.5
Write [MB/s]: 38.30

Ubuntu Live CD Metrics:
Read [MB/s]: 270.1
Write [MB/s]: 49.5

What can I attempt to increase Write Speed?
Should I reconfigure RAID50 settings, or configure different type of RAID?
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Jose Gabriel Ortega CastroTop Rated Freelancer on MS Technologies
Awarded 2018
Distinguished Expert 2018

What if you try a RAID 10 (raid 1 + raid 0), you can do this in pair number of disks.


Is it a guarantee of speed increasing?
Jose Gabriel Ortega CastroTop Rated Freelancer on MS Technologies
Awarded 2018
Distinguished Expert 2018

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Distinguished Expert 2018
Parity RAID (5, 6, 50, etc) and writr-through is gonna kill performance.

Better disks. A better raid type Write-back.. And tiered storage. For write intensive tasks, you'll need to consider those options.

For many tasks, read performance is far more important so your config would be fine. It is a matter of defining importance and bottlenecks.
Top Expert 2014

Hardly surprising it is slow, write-through cache due to lack of battery backup, you could turn write-back caching on, it is a gamble with the data but not so much as turning the disk cache on !

RAID 6 would make more sense than RAID 50 with so few disks, it's only when you get to several (about 7) disks that you need nested RAID. If you can spare the space RAID 10 would be much faster since it does not need 4 I/Os to perform one write.
kevinhsiehNetwork Engineer

RAID 50 for this configuration makes no sense. If you want best performance, use RAID 10. Best write and read speed. If you want more capacity at the expense of write speed, use RAID 5. Nothing else makes sense.

Note that normally RAID 5 isn't viable anymore due to large capacity disks with 10-15 UBR rates. However, since you're using smaller enterprise disks of a limited number, it is okay to use RAID 5 like it's 2008.

If you were using drives over 1 TB, the rule of thumb is RAID 10 or 6. If you had a really large number of drives, I would consider also RAID 60.

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