Slow as card? No way

[Jameslavis]

popped a new Samsung evo 32gb in. 90mb write. Get a slow sd warning. Ideas?

 

[djiboi]

Fake card? Is it marked as U3?

 

[Memerchan]

Fake card? Is it marked as U3?

same here with a Sand Disk class 10 64Gb any suggestion with the Format mine is extFat

 

[djiboi]

Just let the drone format the card. This is mine

https://www.amazon.co.uk/gp/product/B06XYDY93V/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Also you can use this to test the write speed

SanDisk Extreme Micro SD card, 64GB with SD Adapter

 

[Jameslavis]

I read it has to be u3. Guess a 90mb u1 isn’t enough. They need to standardize this crap

 

[djiboi]

That's the best thing about standards, there's so many to choose from!

 

[djiboi]

I think U1 can only write up to 20mb/s but read at 90mb/s

 

[Kilrah]

U1 might write fast enough and probably does but it isn't guaranteed, U3 is so that's what it wants.

 

[Callum]

I think U1 can only write up to 20mb/s but read at 90mb/s

U1 has a guaranteed minimum write speed of 10MB/s (80Mb/s)

U3 has a guaranteed minimum write speed of 30MB/s (240Mb/s)

 

[djiboi]

Thanks for clearing that up. U3 is the way to go for 4k. Otherwise U1 should be fine.

 

[Mike4884]

Yup i have a samsung evo plus but its u3 ...works great

 

[maven4336]

popped a new Samsung evo 32gb in. 90mb write. Get a slow sd warning. Ideas?

Bad card, take back

 

[Mike4884]

Bad card, take back

How do u know its bad? Could just be a u1 (slow)....needs a u3

 

[droneworx]

actually you should be following the new "V" standard. v30,60,90. This is the new tested confirmed sustained video write speeds. Forget U ratings, those dont guarantee sustained write speeds.

 

[Mike4884]

actually you should be following the new "V" standard. v30,60,90. This is the new tested confirmed sustained video write speeds. Forget U ratings, those dont guarantee sustained write speeds.

So what does it mean if a sandisk is u3 v30? Should still be fast enough right?

 

[droneworx]

it means that it is guaranteed to sustain writes at 30MB/sec, because of the V30 ratings. The U3 means that it was tested to 30MB/sec, but wasn't tested to sustain that speed, so it could glitch or drop frames, both bad for video. Just like class 10, was previous the the U ratings, which were for UHS1 ratings, not UHS3 (U3) ratings.

the V is just a newer speed classification because of the newer needs of 4K and 6K/8K RED type cameras, etc.

to answer you question directly, yes V30 is WAY more write capacity than the Air or Pro would need. the Air writes at 12.5MB/Sec, Pro at 7.5MB/Sec

here read this for more details.
Speed Class - SD Association

 

[Callum]

actually you should be following the new "V" standard. v30,60,90. This is the new tested confirmed sustained video write speeds. Forget U ratings, those dont guarantee sustained write speeds.

A U1 and V10 or U3 and V30 are the same thing.
They both have same guaranteed write speeds which have not changed.

The cards are still the same hardware, just a new standard to identify the higher speeds acheived by UHS-II.

 

[droneworx]

A U1 and V10 or U3 and V30 are the same thing.
They both have same guaranteed write speeds which have not changed.

The cards are still the same hardware, just a new standard to identify the higher speeds acheived by UHS-II.

a U3 and V30 card have the same theoretical speed limit, but the U3 cards were not tested in the same fashion as the V30 cards. so the U3 is not guaranteed to maintain that speed rating, whereas the V30 rating is guaranteed.

From Sandisk:
----
UHS Speed Class was introduced in 2009 by the SD Association and is designed for SDHC and SDXC memory cards. UHS utilizes a new data bus that will not work in non-UHS host devices. If you use a UHS memory card in a non-UHS host, it will default to the standard data bus and use the "Speed Class" rating instead of the "UHS Speed Class" rating. UHS memory cards have a full higher potential of recording real time broadcasts, capturing large-size HD videos and extremely high quality professional HD and can reach speeds up to 30 megabytes per second.

Video Speed Class or "V Class", was created by the SD Association to identify cards that can handle higher video resolutions and recording features. This speed class guarantees minimum sustained performance for recording video.
----

 

[Callum]

a U3 and V30 card have the same theoretical speed limit, but the U3 cards were not tested in the same fashion as the V30 cards. so the U3 is not guaranteed to maintain that speed rating, whereas the V30 rating is guaranteed.

From Sandisk:
----
UHS Speed Class was introduced in 2009 by the SD Association and is designed for SDHC and SDXC memory cards. UHS utilizes a new data bus that will not work in non-UHS host devices. If you use a UHS memory card in a non-UHS host, it will default to the standard data bus and use the "Speed Class" rating instead of the "UHS Speed Class" rating. UHS memory cards have a full higher potential of recording real time broadcasts, capturing large-size HD videos and extremely high quality professional HD and can reach speeds up to 30 megabytes per second.

Video Speed Class or "V Class", was created by the SD Association to identify cards that can handle higher video resolutions and recording features. This speed class guarantees minimum sustained performance for recording video.
----

A U1 or U3 rating is not a theoretical rating. It's a guaranteed minimum.

It's the same thing, same cards, just a new standard.

From SD association.


There are three kinds of Speed Classes, "Speed Class", "UHS Speed Class" and "Video Speed Class."


As a characteristic of flash memory, actual transfer speed varies. Variable speeds are difficult to reliably record streaming content such as video because it requires a constant writing speed. All Speed Classes provide the constant speed necessary for video recording by designating a minimum writing performance so that minimum and constant speed could be achieved for camcorders, video recorders and other devices with video recording capabilities under the conditional write operation specified in the standard.

 

[droneworx]

What I can tell you, from my own personal experience... I have a Panasonic GH4 thats a 4/3 camera, this records at up to 200mbps. thats 25MB/Sec. I have 2 identical Sandisk Pixtor cards once is U3 rated, and one is U3/V30 rated. I can tell you that if I use my non V30 rated card, it works, but I experience a higher rate of problems, dropped frames, video failures, etc. If I use them both in my Canon 80D, they both work fine.
So you can choose to use whatever card you want, and post whatever link you like, but im telling you there is a difference.