OWC Thunderbay IV vs Thunderbay 4 (Thunderbolt vs Thunderbolt 2)

Various configurations starting at about $499 without drives.
Thunderbay RAID-5 edition also available.

The original Thunderbay IV (January 2014) was Thunderbolt version 1. The Thunderbay 4 (June 2014) was upgraded to Thunderbolt 2, which is twice as fast.

• OWC Thunderbay IV = Thunderbolt (Jan 2014)
• OWC Thunderbay 4 = Thunderbolt 2 (June 2014)

Both versions share the same enclosure and overall build characteristics. The only difference is in the Thunderbolt version.

Do you need Thunderbolt 2 speed?

Two Mac models currently support Thunderbolt 2: the 2013 Mac Pro and the late 2013 MacBook Pro Retina.

Daisy-chaining = connecting devices in series to each other, versus direct connection for each to the host computer.

Thunderbolt 2 is twice the speed of Thunderbolt, but what are the practical implications? See 2013 Mac Pro: Thunderbolt Performance Tips as well as these summary points.

• Thunderbolt 2 does NOT guarantee that SSDs will run at full speed. Several factors are involved, including the Thunderbolt chipset and implementation. The Thunderbay IV and 4 have some limitations in this regard.
• For hard drive solutions, Thunderbolt v1 an v2 offer no significant difference in speed, because the hard drives are not fast enough to need it. Even four hard drives capable of 200MB/sec (very fast) do not max-out Thunderbolt v1. And that's assuming all four are in use simultaneously.
• With Macs like the 2013 Mac Pro, there are enough Thunderbolt ports that connecting a Thunderbolt v1 hard drive solution directly (without daisy-chaining) is fast enough as per previous point.
• Daisy-chaining any two or more high peroformance solutions should use Thunderbolt 2 for best performance.
• For SSDs, Thunderbolt v2 offers appreciably higher speed for simultaneous use of two or more SSDs, since some SSDs do have the speed to need the bandwidth.
• Systems with only two Thunderbolt ports such as the MacBook Pro really only have one Thunderbolt port if an external display is used, hence daisy-chaining and high performance devices make Thunderbolt v2 a better choice.
• Users of 4K displays require Thunderbolt 2 for 60 Hz operation if the display is daisy-chained to another peripheral (not connected directly to Mac).

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