I plan to upgrade my Intel RST Software RAID1 setup with 2 internal SATA drives to something more versatile:

  • Drives need to be external (they have to reside in an enclosure connected to PC via eSATA or USB3)
  • Enclosure has to be for 4 drives to allow for expansion.
  • Enclosure must support drives of arbitrary size (to allow for future models), i.e. it should not have a preset maximum size limit.
  • I was thinking to go with 2 6Tb 7200rpm UltrStar HGST Drives for a start.

My current setup is as follows: Intel RST Software RAID1 using 2 3Tb WD Caviar Green (internal)

       Sequential Read :    42.796 MB/s
      Sequential Write :    62.639 MB/s
     Random Read 512KB :    16.237 MB/s
    Random Write 512KB :    43.364 MB/s

Test : 500 MB [D: 93.7% (2618.6/2794.4 GB)] (x3) Date : 2015/07/02 12:30:11 OS : Windows 8.1 Pro [6.3 Build 9600] (x64)

In that regard I have some questions:

  1. What data duplication solution I should choose, given that the new drives will reside in an external enclosure connected via eSATA or USB3? Software RAID? Hardware RAID (provided by enclosure as in CFI-B7843JD 4Bay)? Or Windows Storage Spaces (I plan on using Windows 8/10)? What about performance impact and best reliability? I am looking for a solution with at least 1 copy (i.e. as in RAID 1).

  2. Which kind of enclosure should I choose? Any recommendations, given my needs?

  3. Finally, do I absolutely need to go with 7200 rpm drives, or slower drives would suffice? I was looking to at least double my current speeds.

EDIT: For redundancy I am looking only for 1-to-1 mirroring without striping, i.e. so that 1 drive is identical to another one and can be used by itself in another computer/enclosure.

Thank you.


1) Software RAID is more flexible but Windows software RAID cannot be used over USB3. For RAID-1, performance differences are negligible. I'd argue software RAID is most reliable as it is completely independent of any controller or data path failures. eSATA will have better performance than USB3 under almost all conditions. RAID/redundancy over USB3 can only be achieved using Linux, or a built-in mirroring controller in the enclosure, which I do not recommend.

I'm deliberately not detailing RAID-5/6 here as you specify two drives. That said, hardware-RAID or host-RAID (chipset RAID controller) with (e)SATA drives will allow migration from RAID-1 to RAID-5 in future, Windows software RAID does not, but Linux does.

2) Superuser is not the place for product recommendations. I can recommend the type of enclosure though, for the lowest performance impact you want a multi-lane SATA/SAS DAS enclosure (without port multipliers).

3) No. 5400/5900 RPM drives can do 200MB/sec in sequential reads and writes, though more commonly 100-150MB/sec per drive. Better RAID controllers will stripe reads thus doubling that to 200-300MB/sec for two drives, if sequential speed is your only concern. 512K random isn't going to be vastly different, 4K random will be about 1/3rd worse.

  • Thanks for a detailed answer. But what about Windows Storage Spaces? Surely they work over USB3, and in a way are similar to software RAID. Also, then when would I need to look at 7200 rpm drives? Do they provide any advantage nowadays? – Fit Nerd Jul 2 '15 at 11:04
  • @FitNerd: I have no personal experience of it so I can't answer that I'm afraid. – qasdfdsaq Jul 2 '15 at 11:05
  • If possible, I would still appreciate if you mention some enclosures that you know of in the comment. There's nothing wrong with that as long as it addresses the question, which it does. – Fit Nerd Jul 2 '15 at 11:08

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