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PPC
PPC, Computer Hardware Specialist
Category: Computer Hardware
Satisfied Customers: 6
Experience:  Professional Tech & IT Support, Since 1996.
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Hello, I bought a RAID Enclosure: http://www.sansdigital.com/towerraid-/tr5utplus.html

Customer Question

Hello,

I bought a RAID Enclosure: http://www.sansdigital.com/towerraid-/tr5utplus.html

I formatted using MACOS exFat so that it would be read/write on both windows ans Mac OS. I chose a GUID partition. I have it with 5 disk on RAID 5.

I have connected the device by USB 3.0 to my mac mini which has USB 3.0 ports.

I have two other external drives one 2GB and one 3GB which are both also USB 3.0 plugged in to the same mac mini.

The 2GB drive copies at a maximum speed of 10 MB/sec and the 4GB drive copies at maximum speed of 40MB/sec. This is measure writing from the drives to the RAID device.

I included the last bit of information as it may help diagnose the problem.

Anyway, the issue is why are the speeds so slow? There should be no bottleneck due to USB 3.0 and supposedly speed should be 150 MB/sec to 200 MB/sec with this RAID device.

Can you think of any reasons behind this? Alternatively can you advise on the best diagnosis for this?

I am a computer programmer (but know little about this kind of thing) so feel free to be as technical as possible.

Thanks Michael
Submitted: 4 years ago.
Category: Computer Hardware
Expert:  Steve Herrod replied 4 years ago.

Steve Herrod :

Hi, I'll be happy to help with this - can you let me know what version of OSX is installed on the Mac Mini?

Steve Herrod :

and also - when the drives are connected how are they displaying in System Profiler

Steve Herrod :

which should be under the Apple Menu-->About this Mac-->More info

Steve Herrod :

depending on the OSX version

Steve Herrod :

could you let me know how the other external drives show up as well?

Steve Herrod :

Cheers

Steve Herrod :

Steve

Expert:  PPC replied 4 years ago.
Hi Michael,

Did you purchase the enclosure only or did you buy it with drives installed? If you installed your own drives in it, what make / model are they?
Customer: replied 4 years ago.

Hello,


 


Sorry for the very slow reply.


 


I purchased the enclosure only and inserted 5 2GB drives which have previously been healthy in another raid device (ReadyNAS). I have attached a screen shot from the the Sans software showing each drive type. (Correction, JustAnswer are having problems letting me include the image, so drives are shown below:


 


WD20EARS


WD20EARS


WD20EARX


WD20EARX


WD20EARS


 


Side note, the error I got after uploading the image to JustAnswer was below so I removed the image to allow me to post this.


 


Access Denied


You don't have permission to access "http://www.justanswer.co.uk/computer-hardware/7t2e3-hello-i-bought-raid-enclosure-http-www-sansdigital-com-towerraid-tr5utplus-html.html" on this server.
Reference #18.d4e9df5a.1372595128.46840260


 


Thanks


 


Michael