SD cards

[Recoveryone]

I was reading a post about SD cards and someone brought up the use of V60 & V90 SD cards. I have not used one and I am asking who has and what are the tangible factors of using them. The spec sheets are obvious, but what I'm looking for are the results, do they produce a better quality video (depth in color, smoother FPS..etc) please chime in I'm on the fence on buying one and don't want to waste the money if its not worth it.

 

[msinger]

do they produce a better quality video (depth in color, smoother FPS..etc)

Best Memory Card for the DJI Mavic | Mavic Help

Mavic Help is a site for help with DJI Mavic drones. Find the latest fixes, how-tos, guides, accessories, modifications, and more.

www.mavichelp.com

Or just buy one of these:

Great memory cards for DJI drones (November 2021)

Looking for a quality memory card for your DJI drone? Here are several great choices: 32GB SanDisk Extreme 60MB/s write speed 64GB Samsung EVO 60MB/s write speed 64GB SanDisk Extreme 60MB/s write speed 128GB Samsung EVO 90MB/s write speed 128GB SanDisk Extreme 90MB/s write speed 256GB...

mavicpilots.com

 

[Recoveryone]

Best Memory Card for the DJI Mavic | Mavic Help

Mavic Help is a site for help with DJI Mavic drones. Find the latest fixes, how-tos, guides, accessories, modifications, and more.

www.mavichelp.com

Or just buy one of these:

Great memory cards for DJI drones (November 2021)

Looking for a quality memory card for your DJI drone? Here are several great choices: 32GB SanDisk Extreme 60MB/s write speed 64GB Samsung EVO 60MB/s write speed 64GB SanDisk Extreme 60MB/s write speed 128GB Samsung EVO 90MB/s write speed 128GB SanDisk Extreme 90MB/s write speed 256GB...

mavicpilots.com

I already own all of those, the question was, is using a V60 or V90 card better for color depth

 

[slup]

... is using a V60 or V90 card better for color depth

V60 & V90 is a SD cards video speed class ... has nothing at all to do with color depth.

Recording video requires a constant minimum write speed to avoid ‘frame drop’ during recording for a smooth playback. V90 cards are ideal for anyone shooting 4K and beyond – 8K, for example – with frame rates of 60 and 120 fps.

This is the different classes ...

 

[Recoveryone]

V60 & V90 is a SD cards video speed class ... has nothing at all to do with color depth.

Recording video requires a constant minimum write speed to avoid ‘frame drop’ during recording for a smooth playback. V90 cards are ideal for anyone shooting 4K and beyond – 8K, for example – with frame rates of 60 and 120 fps.

This is the different classes ...

View attachment 139692

Thanks, that was the type of info I was looking for.

 

[Meta4]

do they produce a better quality video (depth in color, smoother FPS..etc

Your SD card will either be fast enough, or it won't.
It will give good results or it won't give any results.
You won't get better results from a more expensive card.

 

[Dave Maine]

All image quality is impacted only by the resolution, bit rate, and CODEC chosen.

 

[Etdronehome]

I was about to start a new thread but this seems like an appropriate one to post in. Some of the lead up to this post is contained in:

DJI 10GBPS LIGHTSPEED DATA CABLE

This is the cable that DJI includes with the Cine version. I can’t find a source for the cable (not on DJI store that I can find) and DJI hasn‘t provided any further details on the USB port in the Mavic 3 and/or the cable so buying 3rd party is a bit of a guessing game. I’m interested in...

mavicpilots.com

I have recently purchased some items to up my transfer speed (SD read) rather than upgrade my computer system. My current system is:
Dell 8290 tower


Windows 10, 2TB 7200rpm HDD and a older gen USB C port that does not recognize the M3 when it is plugged in via cable.

After researching I decided to get a Kingston Canvas React Plus micro SD card. There were others with similar spec but I went with Kingston as it is a company with a long history in storage medium and that it came bundled with what they claim to be a USB adapter that enhances performance.

SD and microSD flash memory cards- Kingston Technology

Kingston makes SD and microSD flash memory cards for a variety of devices such as digital cameras, Android phone, drones, dashcams and security cams.

www.kingston.com

I first confirmed that I could use it in my Mavic 3 to record. I tested a range of captures including full 5.1K at 50fps for 3 minutes (it split the file at 3.5GB and started a second one). I didn't attempt to edit any of the footage but my assumption is that it OK as the card far exceeds the write capability of any of the DJI approved cards. I personally don't have any reason to record in 5.1K but included it in the test as I presumed it would stress the write capabilities of the card.

I created a test data set on the Kingston 128GB micro SD card that consisted of 14 files totaling 6.6GB and replicated that exactly on a Sandisk Extreme 128GB micro SD.



I performed a number of data transfers to my PC to compare the performance of the two cards.

The Kingston card comes as a kit that contains the micro SD card, a size adapter and their proprietary USB reader.

The read speed using the card size adapter in the SD slot of the PC was the same from both cards. ~40MB/s over 3 minutes

The Kingston USB adapter did NOT work well. YMMV as some of this might be the age of my PC.

It transferred all of the files from the Sandisk card at the same rate as with the card size adapter - 3 minutes.

When I used it with the "matching" Kingston card the results were surprising. For the first few seconds the transfer rate was about 250MB/s but then suddenly dropped at times below 1MB/s and after 4 minutes I stopped the test (estimated completion time at that point was 24 minutes!) When I removed the USB adapter it was very warm so maybe it has some type of thermal throttling???? I couldn't find anything by Googling the issue.

However I did find a solution to this issue.

I purchased a USB C Satechi UHS-II dongle

Type-C UHS-II Micro SD Card Reader - Satechi

satechi.net

Using this UHS - II capable device I was able to transfer the entire 6.6GB from the Kingston micro SD card in 30 seconds at around 250MB/s. It slowed down a bit at times perhaps due to file size changes or.....

It also substantially shortened the transfer time of the Sandisk card from 3 minutes to 1!

I don't know how this all holds up if there was a larger data set to transfer but I'm impressed so far.

I'm interested in what real world results you are seeing if you have chosen to "upgrade" your SD tech.

 

[Dave Maine]

One other consideration is that there are a multitude of USB specs, beginning with USB 2 which is capable of 480 MB/sec to USB3.2 which is capable of 5,000 Mb/s. A full blown Thunderbolt 3 connection is capable of 10,000 Mb/s and the ongoing USB development will be even faster.

The computer USB port type is also key to transfer speed. It will be specced the same way as a reader. The maximum transfer speed will be determined by the slowest of the 2 ports.

Note that the spec for the DJI drone footage is around 100Mb/s on a SD which will be well below any USB transfer rate. Hard disc drives are much faster, around 800 Mb/s and will be impacted by slow USB interfaces.

 

[Etdronehome]

One other consideration is that there are a multitude of USB specs, beginning with USB 2 which is capable of 480 MB/sec to USB3.2 which is capable of 5,000 Mb/s. A full blown Thunderbolt 3 connection is capable of 10,000 Mb/s and the ongoing USB development will be even faster.

The computer USB port type is also key to transfer speed. It will be specced the same way as a reader. The maximum transfer speed will be determined by the slowest of the 2 ports.

Note that the spec for the DJI drone footage is around 100Mb/s on a SD which will be well below any USB transfer rate. Hard disc drives are much faster, around 800 Mb/s and will be impacted by slow USB interfaces.

I agree the component of the “transfer” that has the slowest “rate” definitely drives the “maximum”. A lot of that is/was covered in that other thread I linked.

It would be nice if drone manufactures would implement the most modern (backwards compatible) components in their new builds. USB4 and UHS-II come to mind.

 

[Dave Maine]

You are missing my point. The videos produced by all but the M3 a can be read off the SD media only at the media’s read spec, which is somewhat greater than 100 Mb/s. Faster hardware will make no difference.

 

[Etdronehome]

You are missing my point. The videos produced by all but the M3 a can be read off the SD media only at the media’s read spec, which is somewhat greater than 100 Mb/s. Faster hardware will make no difference.

I guess I am missing it?

It would help me if we are clear about the same “rate - size” nomenclature.

The numbers I quoted are in Mega BYTES/s. Are you using that or Mega BITS/s. Vendors try to confuse this by sometimes stating things in Gbps because it sounds better imo.

My conversion factors are:
1 Gbps = 125MB/s = 1000Mb/s

The two cards I compared have very different read/write specs. Sandisk is a V30 and Kingston is a V90 see post #4.

All the other hardware factors are identical but the V90 card is a better performer. So the “hardware” of the card does make a difference.

The Kingston V90 card that I chose might NOT work at all in some older models of DJI equipment. I’m hoping someone will try it or another vendors and post their results.

If you referring to modernizing new drone models that’s somewhat more complicated. My comment along those lines was “IF” DJI had used a USB4 type C port and UHS-II spec bus and port inside the M3 they would have increased the SD read/write rate potential when used with a V90 capable card while theoretically maintaining backwards compatibility with older cards.

In this theoretical scenario the SD performance might not have been sufficient to overturn the requirement for the SSD drive in the Cine for ProRes but it would have been a boon to some users who wanted fast field swappable storage.

The cameras on the drones are rapidly evolving HD - 4K - 8K and codecs like ProRes generating relatively huge data sets then having components such as FAST microSD and SSD aboard are essential.

Hardware does make a difference imho.

 

[Dave Maine]

The conventions for speed are MB = megabytes per second
Mb = megabits per second
A MB = 8x Mb.

Card read and writes are in Mb per sec. V30 cards are generally specked for at least 100 Mb/s, other cards are indeed slower. None of these read speeds challenge even USB2 at 480 Mb/s.

SSDs, which is what the M3 uses in it’s cinematic incarnation, are capable of 1000 or more MB/s. Special off-loaders are required to transfer these at the speeds they are capable of. ProRes is a full frame codec with very high quality running at those speeds, and is the best quality choice for high end video production.

 

[Dave Maine]

The V30 will work in any application requiring 100 Mb or less read speeds. The issue only exists for cards that will not write at the speed that the drone’s are spitting out. Lower speeds are just fine.

 

[akdrone]

If the M3 is not trying to write faster than 30 MB/s then buying a faster card will be of no benefit to the shooting. No color, no nothing. However, once you take the card out and toss it in your computer to transfer the data, a V60 or V90 card may (depending on your card reader and such) allow you to transfer the data more rapidly. From what I have gleaned thus far, a V60 or V90 card will make no difference to the read/write times within the Mavic 3 (or any of the recent Mavics that I know of) but they may enhance transfer speed outside of the drone. I'm not an expert; this is just what I have gleaned thus far so correct me if I'm wrong on any of this.

 

[Dave Maine]

Agreed for everything but the Cine version.

"There are a few big headline features shared between both of the new drones, but let’s start with the one reserved for the $4,999 Mavic 3 Cine. The Cine model is capable of filming Apple ProRes 422 HQ footage at 5.1K up to 50FPS, and it has a built-in, but not user-replaceable, 1TB SSD."

This will not be possible with any SD card, as the write speeds re far in excess of them, hence the SSD, as I indicated in my earlier post.

 

[Etdronehome]

If the M3 is not trying to write faster than 30 MB/s then buying a faster card will be of no benefit to the shooting. No color, no nothing. However, once you take the card out and toss it in your computer to transfer the data, a V60 or V90 card may (depending on your card reader and such) allow you to transfer the data more rapidly. From what I have gleaned thus far, a V60 or V90 card will make no difference to the read/write times within the Mavic 3 (or any of the recent Mavics that I know of) but they may enhance transfer speed outside of the drone. I'm not an expert; this is just what I have gleaned thus far so correct me if I'm wrong on any of this.

I don’t really know what the maximum write requirement is on the M3 SD or really how to calculate that. I would assume that the 5.1K 50fps max would be a big part of that however maybe a Photo capture in multiple formats might be a greater “instant” demand. I also think the M3 records other data such as flight info etc. When and how the “peak” write demand is derived is beyond my pay grade.

I think it’s safe to assume that if a less capable card (slower read/write) spec is on the DJI a approved list than anything “faster” would be able to keep pace with “peak” write demands.

I think your analysis is a clear way of thinking about this.

 

[Etdronehome]

Agreed for everything but the Cine version.

"There are a few big headline features shared between both of the new drones, but let’s start with the one reserved for the $4,999 Mavic 3 Cine. The Cine model is capable of filming Apple ProRes 422 HQ footage at 5.1K up to 50FPS, and it has a built-in, but not user-replaceable, 1TB SSD."

This will not be possible with any SD card, as the write speeds re far in excess of them, hence the SSD, as I indicated in my earlier post.

I don’t want to drift into SSD as the topic of the thread is SD however:

SD can be faster than the spec of the SSD in the Cine.



DJI didn’t use high data rate SD in the M3 but the newer spec are VERY fast.

Bus Speed (Default Speed/High Speed/UHS/SD Express) | SD Association

www.sdcard.org

 

[Dave Maine]

You are thinking about it correctly. Any storage media including SD cards will work with any data stream slower than their max write speed.

In the case of drones, DJI controls the write speeds it will deliver, based on the capabilities of it's on-board software and sensor.

 

[Etdronehome]

You are thinking about it correctly. Any storage media including SD cards will work with any data stream slower than their max write speed.

In the case of drones, DJI controls the write speeds it will deliver, based on the capabilities of it's on-board software and sensor.

I’m not sure if the “correct thinking” part of this was to me or @akdrone?

You omitted a very important part imo in the second paragraph. It would be “on-board software and sensor” and HARDWARE like the SD bus.