EOS R5, time required to save to laptop using both CFExpress and SD card

[ricalls]

I intend to rent an EOS R5. I will be using both the CFExpress and SD card to record video in RAW and 4k MP4. The rental package comes with a 64 gb CFExpress card. I will be saving to a 256gb thumb drive via macbook pro running ventura  and canon utility. if i connect the EOS R5 to my laptop via the USB-C, how much time on average will it take to save the 64 gb CFExpress files , when full, to the laptop?

[rs-eos]

There are so many variables at play here. So more info needed to arrive at a reasonable estimate.

• Specific Mac you’re using. List the processor details.
• Which USB-C port are you connecting to? It could make a difference.
• what exact card reader are you using?
• what exact CFexpress card are you using?
• For the videos, please list out any additional details. Ideally, mention the actual bitrates that the footage would be captured at.

The reason that it gets complex is that a media card will have both a sustained read speed and theoretical max. Unfortunately most media card manufacturers place too much emphasis on the theoretical max read.

Your card reader, the cable it attaches to your computer, what data controller is being used for that port will have an impact. For example, is the bandwidth on that USB port being shared with other things at the same time? Or is it truly independent and thus capable of max bandwidth?

Then you have the write speed of the destination drive on your computer. Is that an internal SSD? Or hard drive?  And what is its write speed?

Basically, there will be a weakest link in the chain that the data will flow through. Once you identify the weakest link and know its bandwidth, and the bitrate of what you’ll be capturing, you can then compute things. For example, for every hour of RAW footage at bit rate P, it would take X time to copy. Or every hour of MP4 at bitrate Q, it would take Y time.

[rs-eos]

If trying to find all these details will be too difficult and you have a CFexpress card and reader handy, do the following.

Attach the reader and insert the card. Either find a multi-gigabyte file. Say 8 GB and copy it from the Mac to the card. Then, reboot. Copy the file from the reader back to the Mac and measure that time. Reason for the reboot is to eliminate the possibility of the OS using a file cache.

[ricalls]

-card reader is Sandisk CF Express card reader with sandisk 64GB CF Express car.

- destination thumb drive = sandisk 256 gb usb 3.0 at 130MB/s

- i will use whichever USB-C port that is best

-I will need to use a USB-C hub to connect the camera and flash drive in one port while the power is   in the other port

-laptop = macbook pro 2017, ventura OS, 2.3 ghz dual core intel core i5

- the video to be saved will be 8k raw on a 64 gb CF Express card

I do not need an accurate time. I just need to plan my day as all i have is the 64gb card. Should i budget an hour to save to flashdrive? less or more?

[rs-eos · Accepted solution]

If you're going to be connecting things via hubs, that will lead to more links in the chain.

Assuming for a moment that 130 MBps is the weakest link, it would take around 8 minutes to transfer 64 GB worth of data.  Though be sure to note that some things are bits per second (lowercase b) vs byes per second (uppercase B).  If that speed is actually 130 Mbps, the copy would take 64 minutes.

Recommend though actually trying some file transfers ahead of time.  Data is data, you don't have to have a RAW file.  Just find some 4 GB or 8 GB file you can copy and see how long that will take with your setup.