I purchased a Lexar professional 64gb with my P4P + and when i put my SD card it starts to initailize, then comes up with sd card unknown error please remove. if anyone knows how to fix this problem please let me know.

Check the speed of the card. If it is too fast or too slow it may cause issues. The recommended speeds are in the manual.

There have been a number of issues reported recently with Lexar cards, use it for something else and get yourself a Sandisk Extreme or Extreme Pro series card.

Dump the Lexar card, i messed around with a 128GB card for a few days, tried reformating in the computer, in the drone etc and in the end the issue was the slow write speed.  I change to a Sandisk extreme pro 64GB and also a Samsung Pro+ 128 GB and absolutely no problems at all.

Geebax Posted at 2017-3-24 19:21
There have been a number of issues reported recently with Lexar cards, use it for something else and get yourself a Sandisk Extreme or Extreme Pro series card.

The Sandisk Extreme Pro is UHS-II and it's not recommended for the P4P.
The recommended Sandisk are the Extreme and the Extreme Plus, these are UHS-I and U3 / V30.
There is a Transcend Ultimate with similar characteristics, UHS-I and U3 / V30

Bullflyer Posted at 2017-3-26 12:42
The Sandisk Extreme Pro is UHS-2 and it's not recommended for the P4P.
The recommended Sandisk are the Extreme and the Extreme Plus, these are UHS-1 and U3 / V30.
There is a Transcend Ultimate with similar characteristics, UHS-1 and U3 / V30

The Sandisk Extreme Pro seem to be UHS-2 in the larger capacity cards, above 32GB. I have 6 of them that are 32GB and every one is UHS-1.

Geebax Posted at 2017-3-26 12:53
The Sandisk Extreme Pro seem to be UHS-2 in the larger capacity cards, above 32GB. I have 6 of them that are 32GB and every one is UHS-1.

The Sandisk Pro is only available in 64 and 128 GB, and both are UHS-II.
Did you buy the 32 GB Pro recently ?

Bullflyer Posted at 2017-3-26 13:18
The Sandisk Pro is only available in 64 and 128 GB, and both are UHS-2.
Did you buy the 32 GB Pro recently ?

No, I have had them for about 3 years.

Geebax Posted at 2017-3-26 13:37
No, I have had them for about 3 years.

I have been reading here and there, and I have found out that the "old" Extreme Pro UHS-I is similar in characteristics to the "new" Extreme Plus UHS-I. Same speeds reading and writing. And now the new Extreme Pro are UHS-II

Bullflyer Posted at 2017-3-26 14:21
I have been reading here and there, and I have found out that the "old" Extreme Pro UHS-1 is similar in characteristics than the "new" Extreme Plus UHS-1. Same speeds reading and writing. And now the new Extreme Pro are UHS-2

Most likely. Sandisk's namingh system is very confusing.

It can also depend if the label matches the actual card. There are loads of Sandisk & Lexar rip-off's out there. For many uses the cheaper substitute does not make a difference so people do not know they are not genuine. In our applications the performance is critical so it can expose the fakes. It can be almost impossible to detect some fakes by just physical examination.

Cabansail Posted at 2017-3-26 14:33
It can also depend if the label matches the actual card. There are loads of Sandisk & Lexar rip-off's out there. For many uses the cheaper substitute does not make a difference so people do not know they are not genuine. In our applications the performance is critical so it can expose the fakes. It can be almost impossible to detect some fakes by just physical examination.

But I think you can test the cards with some program. What I don't know is if it is easy to do

I use a Lexar 1000x, 32 Gb with no problems. for me 32 Gb is enough for a flight, then I switch cards...

Antonio76 Posted at 2017-3-27 02:59
I use a Lexar 1000x, 32 Gb with no problems. for me 32 Gb is enough for a flight, then I switch cards... [view_image]

It's suppose that an UHS-II card is not recommended for the P4P.  
It works but not 100% of the performance that this card can do, in devices that are compatible with it.      Have you tried making 4K recordings without having problems?   And the quality of your videos is good?

Bullflyer Posted at 2017-3-27 04:31
It's suppose that an UHS-2 card is not recommended for the P4P.  
It works but not 100% of the performance that this card can do, in devices that are compatible with it.      Have you tried making 4K recordings without having problems?   And the quality of your videos is good?

per P4P specs:
Supported SD Cards        Micro SD
Max Capacity: 128GB

**Write speed ≥15MB/s, Class 10 or UHS-1** rating required

I understand this is the *minimum* requirements...
And, no, so far I haven't done 4K. Waiting to get computer / software upgrade to deal with editing...

Antonio76 Posted at 2017-3-27 04:46
per P4P specs:
Supported SD Cards        Micro SD
Max Capacity: 128GB

You need a 15MB/s write speed at least, UHS speed class 3 or Video speed class V30, these cards reads at least at 30MB/s. The UHS speed class 1,  Video Speed Class V10 or Speed Class 10 reads only at 10 MB/s.      
Take a look at these links:

www.sdcard.org/consumers/choices/speed_class/index.html

www.sdcard.org/developers/overview/bus_speed/index.html

Bullflyer Posted at 2017-3-27 06:19
You need a 15MB/s write speed at least, UHS speed class 3 or Video speed class V30, these cards reads at least at 30MB/s. The UHS speed class 1,  Video Speed Class V10 or Speed Class 10 reads only at 10 MB/s.      
Take a look at these links:

It is all very confusing. with different definitions and names... Anyway, the card I'm talking about  seems to be UHS-2  from Lexar website:
"Lexar® Professional 1000x microSDHC™/microSDXC™ UHS-II cards"
"32GB—up to 150MB/s read, 45MB/s write
Designed for high-speed capture of high-quality images and extended lengths of 1080p full-HD, 3D, and 4K video" , so exceeding (in theory) the DJI specs... Isn't it so?

and it has the UHS-II bus interface  marking  "HC-II" , and the "3 inside the U"  UHS Speed class marking
meaning 30 MB/s  sequential write speed.
So I don't understand why is should "not be recommended" for the P4P?

Just got a Lexar 128gb 633x uhs-i doesn't work in p4pro.  I tried formatting on my mac and pc.  Formatted as fat32 and exfat.  The PC wouldn't let me format as fat32 however the mac did.

jonathanp Posted at 2017-3-27 13:36
Just got a Lexar 128gb 633x uhs-i doesn't work in p4pro.  I tried formatting on my mac and pc.  Formatted as fat32 and exfat.  The PC wouldn't let me format as fat32 however the mac did.

Well manual mentions:
Supported File Systems FAT32 (< 32GB); (exFAT (>32GB)

and write speed must be > 15MB/s class 10 or USH-I rating.  The Lexar card I purchased meets the above requirements.

A couple months ago I went on a road trip to the nearest town and had planned to purchase a Sandisk 128 card at the Staples store.  The sales clerk told me that the Sandisk brand sd cards had been discontinued due to defective products.  I went to the local camera shop, p4p manual in hand, and asked for assistance with getting a good quality sd card there.  The sales associate assured me that the  Pro Master Micro SD 128GB 533x Performance card, 80MB/s Read Speed 20MB/s Write Speed, UHS-1/Class 10 was up to the task and is the card most used by drone pilots in the area.  
I have had nothing but grief from this little bugger.  It constantly drops data,  says it is writing slowly and shuts off completely.  Every third time I use it the data is corrupt and won't load into PremierePro even after re-formattiing it (in the drone).  I just ordered two 64gb Sandisk Extreme plus cards today.

I'm not sure about you P4, but I know that you can accidentally install the SD card into the slot incorrectly.  My friend did that, and was getting that SD card error.   I'm not referring to front and back installation.  He had a P3S, and accidentally installed the card beside the proper slot in the same hole.  It looked like it was installed correctly, but was not.  It would not spring out when pushed it farther in.  If it's not springy, it installed wrong.  It took some doing with a sharp pen knife to finally get it back out.  Just a possible cause!

BugsMc Posted at 2017-3-27 17:53
A couple months ago I went on a road trip to the nearest town and had planned to purchase a Sandisk 128 card at the Staples store.  The sales clerk told me that the Sandisk brand sd cards had been discontinued due to defective products.  I went to the local camera shop, p4p manual in hand, and asked for assistance with getting a good quality sd card there.  The sales associate assured me that the  Pro Master Micro SD 128GB 533x Performance card, 80MB/s Read Speed 20MB/s Write Speed, UHS-1/Class 10 was up to the task and is the card most used by drone pilots in the area.  
I have had nothing but grief from this little bugger.  It constantly drops data,  says it is writing slowly and shuts off completely.  Every third time I use it the data is corrupt and won't load into PremierePro even after re-formattiing it (in the drone).  I just ordered two 64gb Sandisk Extreme plus cards today.

Sadly, this happens to a lot of people, the shops seem to push the card they get the best margin on. Unfortunately these people often have no real knowledge about SD cards.

Some shops may also sourse their cards from dubious sellers. When buying cards it's a good idea to get them from an authorised reseller. I know of one retail outlet who had bought a batch of Sandisk cards directly from China. They were all fakes but they were being sold only a small discount below the normal retail price. Just because you buy from a shop does not mean you are getting the real deal.

Antonio76 Posted at 2017-3-27 08:15
It is all very confusing. with different definitions and names... Anyway, the card I'm talking about  seems to be UHS-2  from Lexar website:
"Lexar® Professional 1000x microSDHC™/microSDXC™ UHS-II cards"
"32GB—up to 150MB/s read, 45MB/s write

-The first thing you need is an UHS-I.
-Second: at least must write at 15MB/s. If you buy a Class 10, these cards writes at least at 10MB/s and not at 15MB/s.                        I recommend to get a V30 Video Speed Class, thinking in 4k videos.

Bullflyer Posted at 2017-3-28 07:25
-The first thing you need is a UHS-1.
-Second: at least must write at 15MB/s. If you buy a Class 10, these cards writes at least at 10MB/s and not at !5MB/s.                        I recommend to get a V30 Video Speed Class, thinking in 4k videos.

Forgive my thickness, but is there a difference between  UHS-1, UHS-2, UHS-3 respectively with UHS-I, UHS-II and UHS-III?  (I think higher numbers in the name mean higher performance, right? ) And if my card writes at 45MB/sec, isn't that more than the "at least 15MB/s" you talk about?

Antonio76 Posted at 2017-3-28 07:47
Forgive my thickness, but is there a difference between  UHS-1, UHS-2, UHS-3 respectively with UHS-I, UHS-II and UHS-III?  (I think higher numbers in the name mean higher performance, right? ) And if my card writes at 45MB/sec, isn't that more than the "at least 15MB/s" you talk about?

UHS-I is a pins configuration and UHS-II is a different configuration.
1 inside an "U" (UHS Speed Class) = 10 inside a "C" (Speed Class) =  V10 (Video Speed Class) = minimun write speed  guarantied  = 10MB/s.
But you need 15MB/s, the next step is a 3 inside an "U" = V30 = minimum write speed guarantied = 30MB/s.
One thing is the maximum write speed of the card, and another thing is the minimum write speed, this speed is guarantied that never will be below 10MB/s in V10 cards or 30MB/s in V30 cards.
Go up to #16 and take a look to the links

I've had really good luck with the 64gb SanDisk Extereme Plus cards in the Inspire 1.  The Inspire 1 originally shipped with a Lexar 16 GB 633x card.  I purchased the 128GB 633x Lexar and its not working.  See package below.  I purchased from BestBuy so I doubt it's a fake" card.

jonathanp Posted at 2017-3-28 09:31
I've had really good luck with the 64gb SanDisk Extereme Plus cards in the Inspire 1.  The Inspire 1 originally shipped with a Lexar 16 GB 633x card.  I purchased the 128GB 633x Lexar and its not working.  See package below.  I purchased from BestBuy so I doubt it's a fake" card.

Support recommends the following :
Here is a list of Recommended SD cards：
1. Lexar 633X Class10 16GB MicroSDHC UHS-I
2. Panasonic 16GB MicroSDHC UHS-3
3. Sandisk Extreme 16GB MicroSDHC UHS-3
4. Lexar 633X Class10 64GB MicroSDXC UHS-3 （Currently for P4 Only）

MAX 128 GB

So the card I purchased is on the list but doesn't work. Maybe a bad copy but doubtful considering it works in the MAC & PC.  

Bullflyer Posted at 2017-3-28 08:17
UHS-I is a pins configuration and UHS-II is a different configuration.
1 inside an "U" (UHS Speed Class) = 10 inside a "C" (Speed Class) =  V10 (Video Speed Class) = minimun write speed  guarantied  = 10MB/s.
But you need 15MB/s, the next step is a 3 inside an "U" = V30 = minimum write speed guarantied = 30MB/s.

OK, I already did that. So suppose now YOU go up to #13 and take a closer look at the card I posted... which has a 3 inside an U, so it is a V30... but you say it is not good??? WHY is it not good, and why do you say that I need a UHS-I ? UHS II and UHS III have the same pin configuration, and DJI recommends mostly UHS III cards (and at least one UHS i , so it is not a pin problem. What is the problem then?

Antonio76 Posted at 2017-3-28 12:37
OK, I already did that. So suppose now YOU go up to #13 and take a closer look at the card I posted... which has a 3 inside an U, so it is a V30... but you say it is not good??? WHY is it not good, and why do you say that I need a UHS-I ? UHS II and UHS III have the same pin configuration, and DJI recommends mostly UHS III cards (and at least one UHS i , so it is not a pin problem. What is the problem then?

Go to this link: www.sdcard.org/developers/overview/bus_speed/index.html
You will see the different Pin configuration in the UHS-I and UHS-II cards.
Now, the 3 inside an U = V30 is correct. But you need " I " wrote in the card (UHS-I) instead " II " (UHS-II)

Bullflyer Posted at 2017-3-28 12:45
Go to this link: www.sdcard.org/developers/overview/bus_speed/index.html
You will see the different Pin configuration in the UHS-I and UHS-2 cards

Look, I know how they look. Why do you keep telling me things that I already know and just don't plainly answer my direct question and say what is that is not good with the Lexar 32 GB UHS II I'm talking about?  The P4P micro card slot accepts (per DJI) both UHS I and UHS III -which has the very same pin configuration as UHS II -  so it also accepts the UHS II.

Antonio76 Posted at 2017-3-28 12:56
Look, I know how they look. Why do you keep telling me things that I already know and just don't plainly answer my direct question and say what is that is not good with the Lexar 32 GB UHS II I'm talking about?  The P4P micro card slot accepts (per DJI) both UHS I and UHS III -which has the very same pin configuration as UHS II -  so it also accepts the UHS II.

You are wrong, the pin configuration is not the same in UHS-I cards than in UHS-II.
Take a look to the link.
UHS-I or UHS-II is the interface, and UHS-1(V10) or UHS-3(V30) is the UHS Speed Class.
Anyway this nomenclature is a bit confusing

Antonio76 Posted at 2017-3-28 12:56
Look, I know how they look. Why do you keep telling me things that I already know and just don't plainly answer my direct question and say what is that is not good with the Lexar 32 GB UHS II I'm talking about?  The P4P micro card slot accepts (per DJI) both UHS I and UHS III -which has the very same pin configuration as UHS II -  so it also accepts the UHS II.

Not according to the specs on the DJI site:

Supported SD Cards        Micro SD  Max Capacity: 128GB
                                        Write speed ≥15MB/s, Class 10 or UHS-1 rating required

The Lexar cards have proved to be troublesome for a number of people, they do not have a high enough sustained write speed.

Simple:  Lexar bad.  Sandisk, samsung good.

Aussie4220 Posted at 2017-3-28 14:40
Simple:  Lexar bad.  Sandisk, samsung good.

That pretty well sums it up.

Aussie4220 Posted at 2017-3-28 14:40
Simple:  Lexar bad.  Sandisk, samsung good.

Yea I agree.  I've had really good luck with my SanDisk cards in GoPro's and Inspire 1.  I'm gonna try and return the Lexar 128gb to BestBuy.

-Sandisk  Extreme and  Extreme Plus, these are UHS-I and U3 / V30.

-Samsung  Pro+ : UHS-I and U3

-Transcend Ultimate: UHS-I and U3 / V30

-PNY  Elite  and  Turbo: these are UHS-I  and  U3

Geebax Posted at 2017-3-28 13:33
Not according to the specs on the DJI site:

Supported SD Cards        Micro SD  Max Capacity: 128GB

Thanks. Finally an answer that makes sense. Not enough sustained speed (I think the keyword here is "sustained"...)

Antonio76 Posted at 2017-3-29 03:20
Thanks. Finally an answer that makes sense. Not enough sustained speed (I think the keyword here is "sustained"...)

Yes, the manufacturers love to advertise the maximum burst speed, but that cannot be maintained for any length of time, and in the Phantom camera, it needs to be.

Geebax Posted at 2017-3-29 13:41
Yes, the manufacturers love to advertise the maximum burst speed, but that cannot be maintained for any length of time, and in the Phantom camera, it needs to be.

And aside from this and as you said before, the cards's namingh system is very confusing.  
It is very easy to get lost with UHS-I, UHS-3, U3, C10,  V30 .......    In the photo of the card above in the #13 you can read at the same time two different classifications, C10 and U3. Can anyone explain this?