Question

As the iMac and the presonus quantum 2 do not ship with thunderbolt cables, I will have to buy one myself. I've read online that cable length greatly affects data transfer speeds.  What length is recommended for the Quantum 2?

Answer 1

I have seen cables up to 30 meters that hit the ISO spec of 20Gb/s. Macsales.com has them as well as shorter. Accell also has them.

I do not know the full spec for the Quantum 2 (awesome interface), but if that cable can hit the ISO spec then it certainly should provide all the bandwidth at full carrier speed the interface can deliver. I know in the hardware I/O space the 10' cables transfer with no issue on very heavy use RAID systems.