I am considering about purchase one to ease my workload but I wonder what the realistic speed of the SD import?
as I do have GH4/GH5 and few other gadget do live event recording,
usually in a busy day there will be
2.5 hours lives, 90mins break, follow by another 2.5 hours live and 90mins before closing,
2.5 hours of recording will produce near 300GB of data,
is it possible to backup those 300GB of data in 90mins windows?
kind of tight by specs
I did google but most review are focus on photo copy,
which leads me nowhere to the answer.
This is a bit anecdotal, but I’m observing a FULL 64GB microSD copy in less than 20 minutes. I would test again tonight and try to time it more accurately, but unfortunately I just emptied all of my SD cards in preparation for vacation. I do feel like it was closer to 10 or 15 minutes but I would hate to steer you wrong. But even if it’s 20 minutes for 64GB, that should get you awfully close to your 90 minute target.
I would say if you have enough “extra” SD cards, you could continue to run the Import/Copy from the cards you just recorded while you are shooting the next event. So even if you can’t dump 300GB in 90 minutes, you can still have pretty close to your ideal workflow.
I do not know how different file types and sizes may affect throughput. For my typical use case, we’re talking about GoPro videos from vacations/diving. Those videos are capped at 4GB each.
Sounds like you’re generating much more data that I do, but really the reason I have the Wireless Pro is not to off-load memory cards, but to perform near real-time backups in case my camera case gets lost or stolen (my Wireless Pro stays at the hotel or wherever). Truth be told, I carry enough memory cards that I don’t need to delete them over the course of a week.
Sorry this isn’t a little more accurate - if I find an opportunity to do a test, I will do so and report back. Otherwise I hope this is at least somewhat helpful.
vary thanks for your sharing 
different file size do severely impact the performance when operating against traditional rotary rust,
which has very limited IOPS due to it’s nature.
most review test only photo copy, many of them show awful result for this reason,
lead me really doubt about it’s performance on card reader.
4G split file is pretty much most camera works with video,
GH5 is the only exception on my hand, which split at around 100GB.
I do have backup SD card to swap,
but ideally it’s better if I can copy all of them on site into a single drive,
so when I got home,
I can just left it copy overnight rather than stay awake and swapping those card for second day.
just got one 4TB model, the real world performance is around 35MB/s,
tested with TS128GSDC300S filled by GH2, 4GB split file,
dd test around SD reader do show 60MB/s read capability,
and hard drive surely can sustain 80MB/s and above,
there are definitely some room that needs to tune to make that speed.
and it overheat after half hour with room temperature 28 degree celsius
