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USB 3.0 vs Thunderbolt Bandwidth (for multiple RAID boxes)

Hi all,


I'm currently at a point where I need to decide whether I should stick with USB 3.0 on my iMac or make the leap to Thunderbolt. Essentially, my end goal is to have two (2) raid boxes each outfitted with 4 or 5 x 3TB HDDs, one of which is used for a time machine backup of multiple machines and the other for every day read/write operations (both direct attached storage and network server-like operations) such as:


  • iTunes library which is stored here, edited directly from the iMac and accessed via home sharing for 10GB video files on Apple TV, iPads, etc. Keep in mind that I primarily use Aperture for organizing and deleting photos/videos. I don't do much if any actual editing.
  • Aperture photo library which is stored here but is often accessed and edited via remotely but within the WiFi-N network. (The iMac is on 1000mbps LAN.)
  • General storage which contains pretty much everything else that isn't OS X or Application based, accessed occassionally.


The RAID boxes in question are a CineRAID CR-H458 (USB 3.0) and a Drobo 5D (Thunderbolt). Currently, I am using the USB 3.0 CineRAID in a hardware RAID 5 setting (not software based) and it seems to work "OK." Sometimes, I have to wait a few seconds for things to come up in finder and sometimes I need to wait a few seconds for a movie to start playing on ATV3, but in all...it works decently. My question is essentially about bandwidth at this point. I don't want to have the interface be the bottleneck of whatever it is I do. Perhaps it's the case that I'm already maxing out the USB 3 bandwidth of about 5Gbps with the first CineRAID box and just don't know it, or perhaps I'm nowhere near that theoretical almost-5Mbps limit and moving to 10Mbps Thunderbolt would be extreme overkill. That's what I'm hear to gather your opinions on. I realize we don't have any hard numbers to prove anything at this point but in general based off the above information, what would you think? If it's the case that I'm nowhere near maxing out the USB 3.0 bandwidth assuming only the devices above were in use, if I introduced a second CineRAID CR-H458, I'm concerned that I'd be bottlenecking my setup at the USB 3.0 interface. There would be some writing, sometimes heavy writing between both boxes in that case as well.


Any thoughts from anyone? All are certainly appreciated!

Posted on Feb 4, 2013 8:51 AM

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Posted on Feb 4, 2013 2:18 PM

Hello,


Open Activity Monitor, Show:>All Processes, sort on CPU%, click on the Disk Activity tab & you can see the throughput used.

Thunderbolt's benefits become clearer using single-drive devices with 3.5" disks. Moving a single file to the GoFlex Desk resulted in similar performance from Thunderbolt and USB 3.0. However, USB doesn't support command queuing. As a result, Thunderbolt takes a 22% lead when transferring bulk files. This is also an advantage when it comes to editing video, as data caching behaves similarly.

http://www.tomshardware.com/reviews/my-book-thunderbolt-duo-pegasus-r4-2big,3222 -14.html


Some benchmarks...


http://www.anandtech.com/print/5797


http://blog.macsales.com/14743-for-most-users-usb-3-0-fulfills-need-for-speed

1 reply
Question marked as Best reply

Feb 4, 2013 2:18 PM in response to Zathrak

Hello,


Open Activity Monitor, Show:>All Processes, sort on CPU%, click on the Disk Activity tab & you can see the throughput used.

Thunderbolt's benefits become clearer using single-drive devices with 3.5" disks. Moving a single file to the GoFlex Desk resulted in similar performance from Thunderbolt and USB 3.0. However, USB doesn't support command queuing. As a result, Thunderbolt takes a 22% lead when transferring bulk files. This is also an advantage when it comes to editing video, as data caching behaves similarly.

http://www.tomshardware.com/reviews/my-book-thunderbolt-duo-pegasus-r4-2big,3222 -14.html


Some benchmarks...


http://www.anandtech.com/print/5797


http://blog.macsales.com/14743-for-most-users-usb-3-0-fulfills-need-for-speed

USB 3.0 vs Thunderbolt Bandwidth (for multiple RAID boxes)

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