Data heavy that is.
I was just doing the math on what it would take to go from a compressed 1080p workflow to a 4K RAW workflow. Most consumer cameras run a datarate of 12-25 Mbps (small b) so between 1.5-3 MBps, or what you can get with a great internet provider these days. Stepping up to mid-level puts you in the 50-200 Mbps range (6.25-25 MBps) or about 1.5 GB per minute, which is a lot. Then there is Cine 4K range. 125-165 MBps (Big B). That's 10 GB a minute. 10! That is, if you want it compressed.
If I wanted true raw it would be 389 MBps, or 23 GB a minute. Also, did I mention that the current price of cards fast enough to record that are ~$6 a GB. That means in data alone its ~$135 a minute* to film at full strength. GREAT SCOTT!
*obviously you reuse the cards. But 2x 64 GB cars only gets you 5 and a half minutes so you will be buying lots of cards.