Extreme cards( micro sd) vs other cards

msinger

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People seem to have the best results with memory cards that write at least at 40MB/s. You can find a list of commonly used memory cards matching that spec here.
 

Meta4

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Can anyone tell me if it's ok to use anything less than 90mbps speed micro sd/sd cards for 4K vids?
It's OK to use any card that meets DJI specs:
Supported SD Card TypesMicro SD
Max capacity: 64 GB. Class 10 or UHS-1 rating required
Using a faster, more expensive card won't be any better as the write speed is determined by the Phantom - not the card.
 

msinger

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With that said, it's also important to note that DJI ships memory cards that write at 40MB/s with the Phantom. They go above and beyond their specs for some reason.
 
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alokbhargava

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Be aware of cheap SD cards. Though they match the specs but fail to really work. Go for reputed make like Lexar, Samsung, SanDisk, .......


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You need less than 8 Mbyte write speed for 4K video. Spending more on higher spec cards pays off when it comes to copying from your card to a PC or other device.
 
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Also, beware of the headline speed - it is almost always the read speed when what you need to know is the write speed. Technically any Class 10 card or better is enough - the video bit rate is 60Mbps - around 6MBps - but I am using only UHS Class 3 cards - which are rated for 30MBps (~300Mbps).

Here, "B" is bytes, "b" is bits and, accounting for overhead a 10x multiplier about right for simple calculations.
 
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Also, beware of the headline speed - it is almost always the read speed when what you need to know is the write speed. Technically any Class 10 card or better is enough - the video bit rate is 60Mbps - around 6MBps - but I am using only UHS Class 3 cards - which are rated for 30MBps (~300Mbps).

Here, "B" is bytes, "b" is bits and, accounting for overhead a 10x multiplier about right for simple calculations.
+1 for throwing 25% overhead in the mix. We need to allow for some brands where the quoted specs are a little on the optimistic side.
 
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Note also some cards with 16go have lower speed/specs than same brand and model but 32 or higher.

Wondering also possible benefit with high speed cards: less frames lost during transition to next file segment?


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8 bits in a byte only works if you use synchronous packets with no delimiters, no start-of and no end-of etc. In a typical streaming protocol it is fair to *approximate* 10 bits to a byte. I speak from some years of exposure to this fun stuff.
 
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By the way, thumbs up to Peter's cat saying hello to us :) Cool and relaxing.

They are *almost* OK with the P4 - I make sure they are well clear if I ever do test flights in the garden, but the topcat (Dicky, NOT Leo who is the one in my Avatar) likes to bat at the P4 when it's prop-less and on a table indoors for maintenance :)

See about 30 seconds into my first test flight video

Dicky is the one nearest me (out of shot on the left) and again appears right near the end, still next to me. He is pretty fearless. :)
 
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They are *almost* OK with the P4 - I make sure they are well clear if I ever do test flights in the garden, but the topcat (Dicky, NOT Leo who is the one in my Avatar) likes to bat at the P4 when it's prop-less and on a table indoors for maintenance :)

See about 30 seconds into my first test flight video

Dicky is the one nearest me (out of shot on the left) and again appears right near the end, still next to me. He is pretty fearless. :)

New GO app 3.0.1 Peter! , definitively a must if you have currently 3.0.0


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