The Vixia HF G60 has a maximum captured bitrate of 150 Mbps (18.75 MBps). So Each 256 GB card should hold just under four hours of footage. A longer duration of course if you're using a lower-quallity codec. So first question, are you recording in 150 Mbps?
Ultimately, an answer to that won't matter since a filled card will have the same amount of data no matter the codec.
So when you say it took an hour to transfer only 14% of your footage? 14% of a 256 GB card? If so, you are transferring data at only around 10 MBps which is incredibly slow.
You'll thus need to figure out what the bottleneck is. First, what specific memory cards are you using (brand, speed class, especially look at its read speed). How are you then transferring your footage to your computer? Connecting via a USB cable (maybe it's USB-1?) What computer to you have? What is the write-speed of your 1 TB drive?
What follows is what I have always done when considering working with video (from the SD days, to HD, now 4K). Includes my backup solution.
I used to use a G50 which also topped out at recording 150 Mbps. I have a SD card reader in my iMac Pro as well as one on an attached LaCie RAID (connected via Thunderbolt 3). Data (footage) is ultimately saved to a different LaCie RAID also connected via Thunderbolt 3. I'm using RAID 10 with 6 disks for read/write speeds of 600 MBps. I'm using SanDisk UHS-I cards with 170 MBps max reads. Thunderbolt 3's bandwidth is 40 GBps. So the memory cards here are the clear bottleneck. At the theoretical max read speed, I can transfer all data from a 256 GB card in around 26 minutes. The 14% mark would be 4 minutes. So this setup is 15 times faster than what you have.
This doesn't mean you need super-fast RAID drives, but you'll want to ensure that you don't have bottlenecks in your system that would cause such slow transfers. Always best to have the bottleneck be the memory cards themselves. That way, as better read speeds come along, you could move to such cards and keep the same computer setup.
I now use a Canon C70 and capture footage at 410 Mps (51.25 MBps). I use AngelBird 256 GB Mark 2 UHS-II V90 cards with max read speeds of 300 MBps. The iMac Pro thankfully has a UHS-II slot, so is able to give me maximum performance. Here, the cards are still the bottleneck. Transfering all 256 GB of data now takes around 15 minutes.
Finally... on backups and general data management.
Whenever I look at new video solutions, I ensure my system has enough storage and backup space to handle storing the original footage (and optimized footage such as ProRes if I'm going to transcode), final output footage, and then backups for both the original and final footage.
When I moved to the C70, I now needed 2.5 times the space to deal with the 410 Mbps codec. Enough space on the data RAID though my backup RAID will need to be upgraded (more storage) in a couple years.
I thankfully don't record much footage per year. Only around 5 hours (1 TB worth). Thus, my main data RAID (12 TB RAID 10) and backup RAID (6 TB RAID 1) are ample for now. The backup RAID currently has 3 TB free, so in a couple years, along with all the photography files, etc, that will get filled up.
In addition to the onsite RAIDs I use, I also have two 2 TB LaCie portable drives that I swap out monthly to an offsite safety deposit box. As I increase the amount of footage, will move to 4 TB units. Then hopefully also SSD if they can be proven to be stable long-term storage formats. At only around 220 MBps write speed, takes hours to transfer the data currently.
All my original video footage as well as final output footage thus exists six times over. Twice on the RAID 10 data drive (since mirrored). Twice on the RAID 1 backup drive (since also mirrored). Once each on the two portable drives. One being also at home; the other being physically offsite. This also means that at any given time, at least once copy is always offsite. I never have both portable drives at home at the same time.
If you ultimately need storage for up to 200 hours of footage, you'll need to figure out the storage requirement. If you only have 1 TB of space, you'd only have around 5.2 GB of storage per hour. Which would be a codec of only 12 Mbps. You'd need 13 TB to store a single copy of 200 hours of footage recorded to that 150 Mbps codec.
--
Ricky
Camera: EOS 5D IV, EF 50mm f/1.2L, EF 135mm f/2L
Lighting: Profoto Lights & Modifiers
