External Hard Drive: Is this fast enough?

Based on what I heard here and elsewhere, I just ordered the G-Tech single drive listed above. This will be fine for my current needs I am sure, and if there is need for something faster and better, well, that job will or should have money in it to pay for an upgrade ;-).

Thanks to everyone.

Those external hard drives are all desktop-sized, which are usually faster in sequential speeds than laptop-sized hard drives. Unfortunately, even the fastest 2-disk RAID 0 hard drive configuration cannot take anywhere close to full advantage of even Thunderbolt 1, let alone Thunderbolt 2 or 3. And that is due to the physical limitations of all spinning hard disks.

That is why Bill gave a good suggestion for a USB 3.x external SSD instead. But if your video files require multiple terabytes of storage, then you're kinda stuck between a rock and a hard place, especially since SSD prices have recently crept upward.

How would you like this sequential read,write rate for only $99 for 256 GB (500 GB , 1 TB and 2TB models available):

This is the Samsung T3 portable USB 3.1 SSD, I use these connected to my PC laptop and put all my Project Files and Media on these an can move almost instantly from my laptop to my desktop and back.  No real performance difference with Thunderbolt and typically at less cost. I now have three of these devices and while your iMac does not have USB 3.1 if you did have you could even expect slightly better.

get us the total video+audio bitrate from mediainfo software. some h.264 stuff is really small but kills the cpu. some stuff is easy on the cpu but kills the slow hard drives.