Jesuan wrote:and what is the time of offloading?? i've made my numbers and i got about 3 hours for a 256 GB full of Raw footage...
BMCC 2.5K 12-bit RAW CinemaDNG uncompressed video is recorded at a rate of 5 megaBYTES per frame. So, for example, a 250GB SSD can hold 30 minutes of this CinemaDNG footage.
I don't have a Thunderbolt-equipped computer, but for example on my 2 yr. old MacBook Pro, it takes 45-min. to copy about 213GB (equivalent to about 20-min. of CinemaDNG footage) via eSATA-2 to 7200rpm SATA-3 hard disk drives connected to the computer.
I estimate performing the same copy operation via USB-3 would take about 50-60 minutes. Via FW800 it might take about 90-110-min., and via USB-2 about 2-3 hours. These are rough estimates, but accurate enough for comparison.
Performing the same copy operation via Thunderbolt (on a newer, faster computer) should result in speeds at least 3-4 times faster. In other words, it would take about 10-15 minutes to copy the same file.
One last note: The BMCC can also record using excellent-quality 1080p 10-bit ProRes 422 HQ compression @ 220 megaBITS/sec. This is 1/5th the data rate of the BMCC's CinemaDNG mode, and can be easily & quickly handled by most any computer and software. For example, that means a 250GB SSD can hold about
2.5 hours of ProRes 422 HQ footage. A half-hour's worth of ProRes 422 HQ footage will copy from SSD to HDD very quickly (just take a minute or so) depending on the speed of the computer & connections. This is one of the reasons I'll shoot ProRes 422 HQ with my BMCC most of the time.