I have a Sandisk Extreme PLUS Card, I made a comparative test with an other U3 card, and with an U1 card.
Members of test was:
View attachment 93877
Samsung 64 GB sd card with U1 certification (which garantees 10MByte/sec data speed)
Kingstone 32GB sd card with U3 certification (which garantees 30MByte/sec data speed) and Class10 certification wich is equialent to U1
Sandisk Extreme PLUS 32 GB card vith U3 and V30 cerifications (which garantees 30MByte/sec data speed)
I measured the real read and write dataspeed of these cards
Samsung U1 card :
View attachment 93879
Both values, 40MB reading speed, and 18 MB write speed is far over the expectation of U1 standard. (10MByte/sec)
But in my experience this card is to slow to record 4K video in same situations (fast changing, very detailed image)
Kingston U3 card:
View attachment 93880
Both values, 77MB reading speed, and 36 MB write speed is over the expectation of U3 standard. (30MByte/sec)
But in my experience this card is to slow to record 4K video in same situations (fast changing, very detailed image)
Sandisk Extrem PLUS U3 card
View attachment 93881
Both values, 78MB reading speed, and 60 MB write speed is far over the expectation of U3 standard, it is on the limit of V60 certification.
In my experience this card is excelent for recording 4K videos in any situation.
During my today's testing was the avarge dataspeed of recording 8,5MByte/sec. It means, there are scenarios, when every one of tested cards is enough.
In this testing I made recording indoor, with low light, at fast moving the picture was smeared because of long exposition time of camera. Smeared picture can be very good compressed, so I wasn't able to increase dataspeed.
But when I was flying with P3SE in sunshine with high speed on low altitude over dense vegetation whose picture was pinned and fine grained, the dataspeed went up to multiple of avarge (such picture can not compress efficiently) over 40MByte/sec, the data cache of camera was filled and overflowed, and recorded video was disturbingly broken.
That's why an P3SE owner needs an SD card with the speed of SanDisk Extrem PLUS