Blackmagic Forum

Hey guys

New to the forum and not 100% this is the right place to post but i'm really at a loss. I bought a samsung T7 and did two full shoots on the drive filming in 6k Open Gate. On the 3rd shoot out of nowhere i got the red exclaimation mark and i'd get about 10-14 seconds of record time before the the recording stopped. Tested the drive and the write speed had dropped to around 140mb/s and before it was around 750 +. I then updated the firm where for the shoot for the next day and it worked for the first hour before the same problem happened again. Long story short is i had to shoot both days in 4k DCI for things to work. We got the job done but 6k / 6k opengate was rendered useless as we were doing interviews and b-roll. The drive is less than a month old.

Just wondering if anyone else has experience this problem with the T7 and if anyone has found a reason and or a solution? Any info would be greatly appreciated.

All the best

Dan

google
blackmagic design supported media

and you will see the original T7 is not supported.

That is typical of unsupported media. It works. And then it does not. Or it does not at all. Whatever it chooses to do.

danhealymusic wrote:Hey guys

New to the forum…

Sadly this opening comment is extremely common on the forum and has become synonymous with “I can’t read or perform a search.”

On the BMD Support webpage you can scroll down the middle column to find media cards and drives that are approved by BMD for the various cameras. There. is also a sticky thread in this Cinematography forum that lists all approved media.


Best of luck.

Using this media, I was simply unable to get the recording to fail. No matter what I did, it would NOT drop any frames. Even at C4K Q0 60 FPS, this card just worked.

I tested on the P4k, but it might also perform well on the 6K. Worth looking at, I think.

https://www.bhphotovideo.com/c/product/ ... _525r.html

I really recommend just using CFExpress. It's not super expensive, it's faster and less error prone than recording to external media, and you can technically make your own DIY CFE Type B cards for cheap. We're talking 1TB for $100 and even slower Type B cards exceed the max speed of the USB-C port.

The Samsung T5, T7, and T7 Shield don't have fast enough sustained write speeds for these cameras. Why do people keep recommending them? When I first bought my regular Pocket 6K, they wouldn't work beyond 5:1, so why would they work correctly now for 6K open gate?

ShaheedMalik wrote:The Samsung T5, T7, and T7 Shield don't have fast enough sustained write speeds for these cameras. Why do people keep recommending them? When I first bought my regular Pocket 6K, they wouldn't work beyond 5:1, so why would they work correctly now for 6K open gate?

The T7 was never supported and the T5 has its limits, but the T7 Shield is absolutely able to sustain write speeds faster than the Pyxis, CC6K, or any Pocket can throw at it. There are some codec/compression/FPS/resolution combinations that can be problematic but that's not because of the T7 Shield; the USB port on the cameras I mentioned are just limited to USB3 speeds. USB3 is advertised as a 5Gbps standard (aka 625MB/s) but it never hits that and you should normally expect around 450MB/s in real world use.

That said, the BMCC6K/Pyxis 6K Open Gate 24FPS @ Q0 shouldn't be a problem for a T7Shield or a T5. They've both got enough grunt for that.

Alex Mitchell wrote:

ShaheedMalik wrote:The Samsung T5, T7, and T7 Shield don't have fast enough sustained write speeds for these cameras. Why do people keep recommending them? When I first bought my regular Pocket 6K, they wouldn't work beyond 5:1, so why would they work correctly now for 6K open gate?

The T7 was never supported and the T5 has its limits, but the T7 Shield is absolutely able to sustain write speeds faster than the Pyxis, CC6K, or any Pocket can throw at it. There are some codec/compression/FPS/resolution combinations that can be problematic but that's not because of the T7 Shield; the USB port on the cameras I mentioned are just limited to USB3 speeds. USB3 is advertised as a 5Gbps standard (aka 625MB/s) but it never hits that and you should normally expect around 450MB/s in real world use.

That said, the BMCC6K/Pyxis 6K Open Gate 24FPS @ Q0 shouldn't be a problem for a T7Shield or a T5. They've both got enough grunt for that.

The T7 and the T7Shield are actually the same drive internally with some firmware changes. If you look at the actual sustained write speeds, it's the exact same drive under USB3.0.

People get good batches of them, and Blackmagic made some camera firmware changes to better work with them, but they were always poor choices for recording to. Eventually everyone has problems.

ShaheedMalik wrote:The T7 and the T7Shield are actually the same drive internally with some firmware changes. If you look at the actual sustained write speeds, it's the exact same drive under USB3.0.

No, they aren't the same drive and you should probably take a second to reflect on why you confidently claimed something that is so obviously not true without even doing a cursory search to back yourself up:

Anandtech wrote:Moving from the 5th Gen. 92L (96T) V-NAND in the T7 Touch to the 6th Gen. 128L (136T) V-NAND brings about a 10% improvement in latency and 15% reduction in power consumption, as per Samsung's claims. As we shall discovered further down in this review, these aspects do bear out when looking at various evaluation results.

Feel free to go over Anandtech's breakdown with tests. They might be similar drives, but the improvements in the T7Shield are what makes it BMD verified. Tons of folks, myself included, seem to be using them just fine.

Alex Mitchell wrote:

ShaheedMalik wrote:The T7 and the T7Shield are actually the same drive internally with some firmware changes. If you look at the actual sustained write speeds, it's the exact same drive under USB3.0.

No, they aren't the same drive and you should probably be embarrassed for confidently claiming something that is so obviously not true without even doing a cursory search to back yourself up:

Anandtech wrote:Moving from the 5th Gen. 92L (96T) V-NAND in the T7 Touch to the 6th Gen. 128L (136T) V-NAND brings about a 10% improvement in latency and 15% reduction in power consumption, as per Samsung's claims. As we shall discovered further down in this review, these aspects do bear out when looking at various evaluation results.

Feel free to go over Anandtech's breakdown with tests. They might be similar drives, but the improvements in the T7Shield are what makes it BMD verified. Tons of folks, myself included, seem to be using them just fine.

Reading is fundamental:

If you look at the actual sustained write speeds, it's the exact same drive under USB3.0.

The T7 Shield chart shows write speeds above 600MBps which means it's running at above USB3.0. The second chart shows exactly what happens on the T5, T7, and the T7 Shield on USB3.0 with the Blackmagic Cameras.

SATA 3 has a maximum theoretical bandwidth of 6 Gbps1, which translates to a maximum sequential read/write speed of around 600 MB/s.

ShaheedMalik wrote:The T7 Shield chart shows write speeds above 600MBps which means it's running at above USB3.0. The second chart shows exactly what happens on the T5, T7, and the T7 Shield on USB3.0 with the Blackmagic Cameras.

So that point in the graph where the T7 Touch craters to around 100MB/s is just invisible to you or...?

Alex Mitchell wrote:

ShaheedMalik wrote:The T7 Shield chart shows write speeds above 600MBps which means it's running at above USB3.0. The second chart shows exactly what happens on the T5, T7, and the T7 Shield on USB3.0 with the Blackmagic Cameras.

So that point in the graph where it craters to around 100MB/s is just invisible to you or...?

You literally said this earlier:

The T7 was never supported and the T5 has its limits, but the T7 Shield is absolutely able to sustain write speeds faster than the Pyxis, CC6K, or any Pocket can throw at it. There are some codec/compression/FPS/resolution combinations that can be problematic but that's not because of the T7 Shield; the USB port on the cameras I mentioned are just limited to USB3 speeds. USB3 is advertised as a 5Gbps standard (aka 625MB/s) but it never hits that and you should normally expect around 450MB/s in real world use.

Then you post a chart were the T7 Shield is above 600MB/S.

You don't understand that these drives will only run at USB3.0.

Alex Mitchell wrote:

ShaheedMalik wrote:The T7 Shield chart shows write speeds above 600MBps which means it's running at above USB3.0. The second chart shows exactly what happens on the T5, T7, and the T7 Shield on USB3.0 with the Blackmagic Cameras.

So that point in the graph where the T7 Touch craters to around 100MB/s is just invisible to you or...?

If you understand that T7 Touch crater, you would understand why people have trouble out of the T5, T7 (some people have gotten them to work on their system), and the T7 Shield.

Some people get good batches, then some end up with problems which is why the original poster is wondering their drive is suddenly acting up.

The problem is mainly the manufacturers do whatever they want and the USB standard is basically not a standard at all. IMO the way you hold the USB-C cable while inserting it, and which tune you whistle will determine if the next 2h30 shot will fail or not.

I bought a T9 4TB, which is on the supported list. It did NOT format in the BMCC 6K FF - it just froze the camera completely, every time. I had to format it in PC and then it worked - flawlessly.

Weird for a drive that is on the supported list.

In short : NEVER use a drive that is not on the list, because even those on the list will misbehave without ample testing and doing the firmware upgrades ...

Yannick Willox wrote:The problem is mainly the manufacturers do whatever they want and the USB standard is basically not a standard at all. IMO the way you hold the USB-C cable while inserting it, and which tune you whistle will determine if the next 2h30 shot will fail or not.

I bought a T9 4TB, which is on the supported list. It did NOT format in the BMCC 6K FF - it just froze the camera completely, every time. I had to format it in PC and then it worked - flawlessly.

Weird for a drive that is on the supported list.

In short : NEVER use a drive that is not on the list, because even those on the list will misbehave without ample testing and doing the firmware upgrades ...

Those drives run at full speed hooked up to a PC, but only USB3.0 & SATA 3 speeds hooked up to the camera.

The stop mean the camera cannot write a data on your USB-disk. The reason is lack of disk's writing speed (option in the menu "stop recording if disk drop frame").
1-st unoblivious reason i has got in my practice - the bad usb cable. The situation is so that camera see the disk. Can format it. Can write there some video, but it is unstable. I have changed the cable to the better (and cheaper!) version and then it starts work fine!
2-st we have a 4 or 5 BMPCC 6K Pro in our production studio. We are using them only with T7 (not t-5, cuz it out of stock) in full sensor mode - and our guys never told me about some problems with it.
Be sure uve got last firmware for ur SSD (Samsung Magician utility can fix that very quckly).
At last u may try to reduce recording bitrate - to 8:1 - we are using that option and i never seen some compression artefacts on those videos (for a few years of working).