Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

2.7k or 1080...transmission issues with 2.7?

Discussion in 'Pro/Adv Discussion' started by dtviewer, Aug 14, 2016.

  1. dtviewer

    Joined:
    Jul 24, 2014
    Messages:
    293
    Likes Received:
    79
    When I first started flying my p3a I used 1080, but then switched over to 2.7 when I found out how much better frame grabs were when using the 2.7.
    I don't know if its coincidence or not but both times I used 2.7 I had glitching and freezing on the video feed so I switched back to 1080.

    Was the problem because of the 2.7? Could it of been because of the cheap(er) acer tablet I was using? Was it because I was new to the p3? Coincidence?
    I'll be honest...I've been afraid to experiment and try it again but would love to go back to the higher resolution.

    Anybody who uses 2.7k with the p3 want to chime in?
    Thanks
     
  2. alokbhargava

    Joined:
    Sep 28, 2015
    Messages:
    5,152
    Likes Received:
    1,664
    Location:
    San Francisco, CA
    Your tablet gets only 720 p, so the main problem seems to be with the quality of your SD card.


    Sent from my iPhone using PhantomPilots
     
  3. dtviewer

    Joined:
    Jul 24, 2014
    Messages:
    293
    Likes Received:
    79
  4. Tenly

    Joined:
    Mar 27, 2016
    Messages:
    602
    Likes Received:
    218
    2.7k vs 1080p only controls the resolution of the video that is saved to your SD card. The video streamed back to your device is 720p in both cases and is completely unaffected by the setting.

    Purely a coincidence I would think. Go back to 2.7k and enjoy the higher quality frame grabs. If you have any concern over the speed of your SD card and how fast you can save pictures to it - I've done some testing and found that the SanDisk Extreme Pro 32GB card is one of the best I've seen. A lot of the manufacturers play games with their product claims. I would pass on any product that doesn't clearly break out read speed and write speed. If they don't tell you what the write speed is on the packaging - it's probably crap!
     
  5. dtviewer

    Joined:
    Jul 24, 2014
    Messages:
    293
    Likes Received:
    79
    Thanks for the replies.
    I'm going to grab a new card and try it out next weekend.

    Edit: Looks like both of you guys may have nailed it.
    My Transcend even though it is class 10 it is U1 and 45mb/s. The SanDisk you mentioned is class 10 but U3 and 95mb/s.
     
  6. msinger

    Approved Vendor

    Joined:
    Oct 30, 2014
    Messages:
    19,103
    Likes Received:
    5,624
    Location:
    US
    It only writes at 20MB/s though. Memory cards that write at least at 40MB/s tend to work the best with the Phantom 3. I have a list of commonly used memory cards (along with their write speeds) here.
     
    chiefgeek and dtviewer like this.
  7. dtviewer

    Joined:
    Jul 24, 2014
    Messages:
    293
    Likes Received:
    79
  8. Tenly

    Joined:
    Mar 27, 2016
    Messages:
    602
    Likes Received:
    218
    These are my own, messy, scribbled notes. I tested almost everything I had connected to my iMac - SSD drives, USB flash drives, external USB drives, RAID arrays and SD/microSD cards.

    In the SD category - the "SanDisk Extreme Pro" blow away anything else I've purchased in that form factor with a blazing 72MB/s write speed! The Panasonic 16GB microSD offers passable Phantom performance with its 35MB/s write speed - but I like my memory cards to serve double duty in my drone and my DSLR and I find that the SanDisk ones I use do a much better job keeping up when shooting in "burst mode". For the $15 difference in price, it's a no-brainer for me - but as the other poster mentioned, anything that offers greater than 40MB/s write speed is going to be able to keep up with the Phantoms 4K video stream (and likewise with 2.7k) - so go ahead and make your own decision based on all your use cases.

    The speed test program I was using is called "Black Magic Disk Speed Test" and it can test anything that connects to your computer and presents a file system.

    ImageUploadedByPhantomPilots1471294478.330964.jpg
     
  9. dtviewer

    Joined:
    Jul 24, 2014
    Messages:
    293
    Likes Received:
    79
    Thanks! I ordered my new U3 card and should have it by Wednesday!
     
  10. Mocho

    Joined:
    Jun 16, 2016
    Messages:
    315
    Likes Received:
    64
    Location:
    Alberta, Canada
    Anyone know how big the cache memory is in the P3P? I'm assuming the cache is used for writing out to the SD card.
    Just curious why my Sandisk Ultras SEEM to work properly shooting 4K video?
    I thought the go pro 4K video writes at a constant speed of around 8Mb/s. So I'm wondering if paying the extra $$ is buying us anything? Especially if we format the card every time it's full, so there is no fragmentation.
     
  11. Oso

    Oso

    Joined:
    May 19, 2015
    Messages:
    2,542
    Likes Received:
    1,487
    Location:
    Sacramento CA
    Mike, I'm a bit surprised with your post. In the past, you've noted the fact that the Phantom 3 is limited to writing at a max of 7.5MB/s. As such, any class 10 (U1) card should work. A faster card normally also has a fast read speed as well which helps with transferring from the card, but not with writing to the card due to the hardware limit. I have also noted the same several times.

    Why the change in advice to now say a 40MB/s write card is best?
     
    JoBe likes this.
  12. msinger

    Approved Vendor

    Joined:
    Oct 30, 2014
    Messages:
    19,103
    Likes Received:
    5,624
    Location:
    US
    I have not changed my advice. If you've been following the products I suggest (like my recommended list of tablets or my recommended list of memory cards), you've probably noticed my recommendations don't always match DJI's recommendations. Instead, I recommend products that I know will well for Phantom owners. I would never recommend a product that I would not feel good about using myself.

    It's true that the Phantom can only write a max of 7.5MB/s when recording video. Let's not forget that many people are also saving RAW photos to the same memory card. The average RAW photo is somewhere around 24MB. As you can imagine, it's going to take longer to save a photo if you're using a memory card that can only write at a maximum of 8MB/s. And, to add some icing to that cake, it's important to note that memory cards are not able to write at their maximum write speed the entire time.

    Here's why I'm recommending (and have always recommended) people use memory cards that write at least at 40MB/s:
    • The memory card DJI ships with most Phantoms writes at 40MB/s. If they didn't think that higher write speed was beneficial, I'm thinking they would have opted to save a few bucks and ship the cheapest class 10 memory card they could find.
    • When transferring data to/from the memory card, it's nice to be able to get the job done in less time.
    • Memory cards that write at 40MB/s+ are not much more expensive than the cheapest class 10 memory cards.
    • People sometimes lose frames when recording 4K video with the cheapest class 10 memory cards.
    • People never have trouble when using the memory cards I recommend.
     
    jeditim and mikesmiley like this.
  13. captainmilehigh

    Joined:
    Apr 4, 2016
    Messages:
    809
    Likes Received:
    380
    Location:
    Northeast Florida
    @msinger, thanks for all the above info. Makes a choice much easier.


    Sent from my iPad using PhantomPilots
     
  14. mikesmiley

    Joined:
    Apr 3, 2016
    Messages:
    452
    Likes Received:
    264
    Location:
    Sacramento, CA
    I've always been a SanDisk fan. They make good cards. That being said, they recently made it more troublesome and expensive for me to RMA a bad MicroSD than it was to just go buy a new one. So I bought a PNY, and it's blazing fast.
     
  15. captainmilehigh

    Joined:
    Apr 4, 2016
    Messages:
    809
    Likes Received:
    380
    Location:
    Northeast Florida
    50 MB's write speed fast enough on PNY ?


    Sent from my iPad using PhantomPilots
     
  16. mikesmiley

    Joined:
    Apr 3, 2016
    Messages:
    452
    Likes Received:
    264
    Location:
    Sacramento, CA
    I would say yeah, for sure.
     
    captainmilehigh likes this.
  17. captainmilehigh

    Joined:
    Apr 4, 2016
    Messages:
    809
    Likes Received:
    380
    Location:
    Northeast Florida
    Ok thanks. I've always used SanDisk Extreme and not familiar with PNY.


    Sent from my iPad using PhantomPilots
     
  18. mikesmiley

    Joined:
    Apr 3, 2016
    Messages:
    452
    Likes Received:
    264
    Location:
    Sacramento, CA
    Don't get me wrong. I'm not trying to steer anyone away from SanDisk. They make a good product.

    They just pissed me off by making me jump through hoops to RMA a card that *retails* for about $18. Their cost? Oh, I dunno, about $3.50 if I had to guess. It just left a bad taste in my mouth, and I chose to spend my money elsewhere. So far, very pleased with the PNY.
     
  19. captainmilehigh

    Joined:
    Apr 4, 2016
    Messages:
    809
    Likes Received:
    380
    Location:
    Northeast Florida
    Understood. Sounds like PNY would be a good 2nd choice if needed. Thanks for the insight.


    Sent from my iPad using PhantomPilots
     
    mikesmiley likes this.