Author Topic: Scandisk 128GB CF card 160MBs/sec only records 1920 HD  (Read 600 times)

danielg

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Scandisk 128GB CF card 160MBs/sec only records 1920 HD
« on: November 21, 2018, 02:45:27 AM »
Hi. Totally new here.

I want to shoot 14bit RAW (priority) and would like to shoot at 4k, but am happy to shoot at lower resolutions like 2200, 2500, etc.

I have installed ML on a 5D3 and everything works good so far, except for the fact that the highest I can record is 1920x1080.
Anything higher than that it says the write mode is not possible. It says it needs at least 89 MBS sec but I have a 160 MB sec CF card.

Has anyone had this problem?

Walter Schulz

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Re: Scandisk 128GB CF card 160MBs/sec only records 1920 HD
« Reply #1 on: November 21, 2018, 04:48:20 PM »
With uncompressed 14-bit RAW this is about the cam's limitation.
Vertical pixels x horizontal pixels x bit depth x fps / 8 = bandwidth needed
1920 x 1080 x 14 x 24 / 8 -> 87091200 bit/s -> 83.1 MiByte/s

Load module bench.mo, restart cam, go to Debug -> Benchmarks -> Card benchmarks -> Quick R/W benchmark (1 min)
Result will tell you the maximum write rate your cam-card combination is able to do.
Now take into consideration there is some computing overhead during recording. Thus "real life" numbers will be lower.

If you want higher resolutions may want to try lossless compression and/or lower bit depth.
 
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