BMPCC 6k stops recording in 6k 50 frames

Hi,

I have a Samsung T5 SSD with 2 TB for my newly bought BMPCC 6k and when I try to record in 6k with 50 frames it stops after like 2 seconds even when the "Stop Record after Drops Frame" option is toggled off. With 30 frames in 6k it works just fine.

This were my record settings, just the T5 SSD is not shown because I did not have it connected while taking the picture, but the SSD was definetly selected as the record medium:

https://drive.google.com/open?id=1PO4Rb ... cObPpCtQZW
https://drive.google.com/open?id=115JYq ... EGp5tbEGyI

The T5 SSD should be able to record all settings without dropping frames, shouldn't it?

Thank you!

hi i have the same problem now, do you find a solution?

hi i have the same problem now, do you find a solution?

You have to use higher compression. Despite what people think the T5 should be able to handle, it doesn't. Then also the USB-C port of the PCC6k/4k is USB 3.1 Gen 1 and restricted to a theoretically limit of 5 GBit which translates to 625 MB/s minus 20% protocol overhead. In the end no more than 500 MB/s are available through USB 3.1 Gen 1. And that would be the best case.

@ 50fps
BRAW 3:1 needs 506 MB/s
BRAW Q0 needs 304 to 759 MB/s
ProRes HQ needs 471 MB/s

BRAW 5:1 needs 304 MB/s
BRAW Q5 needs 76 to 217 MB/s
ProRes 422 needs 314 MB/s

I have created an MS Excel and LibreOffice sheet where you can put in the frame rate and it calculates the datarates for 6k, 4.6k, 4k, UHD, 2k, HD for all available codecs and compressions.

Datarates for Blackmagic Camera Codecs v2a 2020.zip

(25.31 KiB) Downloaded 627 times

I have created an MS Excel and LibreOffice sheet where you can put in the frame rate and it calculates the datarates for 6k, 4.6k, 4k, UHD, 2k, HD for all available codecs and compressions.

Robert, Thanks for the calculator. It can come in pretty handy.

To date, I'm informed by BMD support that there are no C-Fast 2.0 cards or SSD fast enough to write BRAW 3:1 @ 6K 50fps. There is however an option of using an NVME drive with an advertised sustain write of 3000MB/s but with USB 3.1 Gen 1 will probably go as high as 600MB/s transfer, you will able to do so. That's theoretical since I have not tried it yet.

Ellory, the NVME doesn't help, as the practical limit of USB 3.1 Gen 1 is 500 MB/s - that is the limit because of the signal error correction encoding.

Ellory, the NVME doesn't help, as the practical limit of USB 3.1 Gen 1 is 500 MB/s - that is the limit because of the signal error correction encoding.

Ah, it's far less than I was told then. Then if BRAW 3.1 @50fps requires a sustain write of 503MB/s and Q0 shot other than mostly white/low contrast (nothing like confetti shots if you know what I'm referring to), then no media today can practically write out at those modes without drop frames.

I haven't tried to record in 3:1 yet.

The problem for me was that I used the wrong USB C cable. I now have a very short cable from Tilta and it's all fine but I don't know the least compression I tried yet.

I wonder how they tested out the 50fps 3:1 6K claim if there is no media for sale that supports it.

I wonder how they tested out the 50fps 3:1 6K claim if there is no media for sale that supports it.

It's not that there are no media that they can test out 50fps 3:1 6K to claim it works. They cannot certify any media that will be able to sustain writing out at 50fps 3:1 6K without dropping frames. That's the difference.

If we want to use a media that can write 50fps 3:1 6K with acceptable risk of drop frames, by all means there's no stopping us but ourselves. Right?

Thanks for the quick reply... I think my question still stands... I'm not complaining; just wondering how they know the camera can actually sustain writing with those levels if there is no media to test it with. It could be an issue with software or hardware in the camera. Again; not complaining at all; just was curious.

Thanks for the quick reply... I think my question still stands... I'm not complaining; just wondering how they know the camera can actually sustain writing with those levels if there is no media to test it with. It could be an issue with software or hardware in the camera. Again; not complaining at all; just was curious.

Completely understand. It's the black art of BlackMagic.

Ellory, the NVME doesn't help, as the practical limit of USB 3.1 Gen 1 is 500 MB/s - that is the limit because of the signal error correction encoding.

Just giving this some thought again. If the practical limit of USB 3.1 Gen 1 transfer speed is 500MB/s, and that is the port available on the BMPCC 6K, then there is practically no way to record at BRAW 3:1 @ 6K 50fps regardless of available fast media with the required sustained write speed. Even with Q0 @ 6K 50 fps, unless the scene has very little action or a less contrast shot that goes not exceeds capturing the 500MB/s write speed. How do you think this will be fixed if the weakest link is the port? Will there even be a solution? Maybe I'm missing something.

Any new word on this issue?

The approved media list is a bit confusing which category is the fastest one to select to give you the most leeway at this point? 3:1?

This remains an unsolved issue with the 6k not being able to record higher frames rates at Braw 3.1 (Braw Q0 is way out of reach).
Looking at the current available recording media on the market, it seems the Sony G-Series C-FAST cards are the only ones listed with a theoretical max write speed above 500Mb/s, able to handle at least the Braw 3.1 writes. Yet, there hasn't been much mention of these cards, even though they are on BMD's recommended list.
Does anyone have experience with these cards, especially recording at Braw 3.1 @ 50fps.

You can record 6K 50FPS Q3:1 on a Samsung T5 SSD, as long as your ISO is below 1250 I believe. There was a YouTube video on this by Gerald Undone and I tested it out and it works.

At the 5 min marker

very smarth thanks!!

hi i have the same problem now, do you find a solution?

You have to use higher compression. Despite what people think the T5 should be able to handle, it doesn't. Then also the USB-C port of the PCC6k/4k is USB 3.1 Gen 1 and restricted to a theoretically limit of 5 GBit which translates to 625 MB/s minus 20% protocol overhead. In the end no more than 500 MB/s are available through USB 3.1 Gen 1. And that would be the best case.

@ 50fps
BRAW 3:1 needs 506 MB/s
BRAW Q0 needs 304 to 759 MB/s
ProRes HQ needs 471 MB/s

BRAW 5:1 needs 304 MB/s
BRAW Q5 needs 76 to 217 MB/s
ProRes 422 needs 314 MB/s

I have created an MS Excel and LibreOffice sheet where you can put in the frame rate and it calculates the datarates for 6k, 4.6k, 4k, UHD, 2k, HD for all available codecs and compressions.

Datarates for Blackmagic Camera Codecs v2a 2020.zip

Hi,

I have just encountered a similar issue with my PCC6K and Samsung T5 1TB even shooting in UHD prores 422.

It was all working fine, moved the setup to a gimbal and used a different USB C - USB C cable. The record dropped frames at 48.10 secs and stopped every time.

Returned to original USB C cable (the one supplied with T5 drive) works perfectly again.

I guess all USB C are not created equal.

UPDATE to old thread. Problem solved. Want to record 6K @ 50fps all day long at Q0 setting ?

Warning the file sizes are huge. about 28-30G per min. But yes you can record to a SSD at those rates and the BMPCC 6k loves it.

What SSD will do that you ask. I saw this guy take an Inland Platinum 4TB SSD M.2 2280 NVMe PCIe Gen 3.0 x 4 3D NAND Internal Solid State Drive and put it into a cheap asus SSD case : ASUS ROG STRIX Arion Aluminum Alloy M.2 NVMe SSD External Portable Enclosure Case Adapter, USB 3.2 Gen 2 Type-C (10 Gbps), USB-C to C and USB-C to A Cables, Fits PCIe 2280/2260/2242/2230 M Key/B+M Key.

Drive is $479 for 4TB and Case was $57. Both came same day on amazon. I knew just the test. See if that 6k BRAW could choke yet another SSD. What's the point of having a setting no media will support.

formatted it up in exFAT, plugged it into BMPCC 6k usb port and camera said 340 minutes of record time on drive.Saw it no problem. Set it to be primary record drive, Set camera to constant Quality Q0, engage HFR at 50 fps...........I stopped it after 7 minutes of continuous recording because it was getting ridiculous. That SSD is rated at 3400 MB/sec read and 3000 MB/sec write. Best $500 i ever spent for this great little camera. And it's not even approved recording media. Running camera version 7.3 I think. The latest. Hands down best SSD for BMPCC 6k.

I might add that with those settings I was lucky to get 5-12 seconds before camera quit recording with my T5's. CFAST did a little better.

Now just need to convince SmallRig or Tilta to make a holder for it.

UPDATE to old thread. Problem solved. Want to record 6K @ 50fps all day long at Q0 setting ?

Warning the file sizes are huge. about 28-30G per min. But yes you can record to a SSD at those rates and the BMPCC 6k loves it.

What SSD will do that you ask. I saw this guy take an Inland Platinum 4TB SSD M.2 2280 NVMe PCIe Gen 3.0 x 4 3D NAND Internal Solid State Drive and put it into a cheap asus SSD case : ASUS ROG STRIX Arion Aluminum Alloy M.2 NVMe SSD External Portable Enclosure Case Adapter, USB 3.2 Gen 2 Type-C (10 Gbps), USB-C to C and USB-C to A Cables, Fits PCIe 2280/2260/2242/2230 M Key/B+M Key.

Drive is $479 for 4TB and Case was $57. Both came same day on amazon. I knew just the test. See if that 6k BRAW could choke yet another SSD. What's the point of having a setting no media will support.

formatted it up in exFAT, plugged it into BMPCC 6k usb port and camera said 340 minutes of record time on drive.Saw it no problem. Set it to be primary record drive, Set camera to constant Quality Q0, engage HFR at 50 fps...........I stopped it after 7 minutes of continuous recording because it was getting ridiculous. That SSD is rated at 3400 MB/sec read and 3000 MB/sec write. Best $500 i ever spent for this great little camera. And it's not even approved recording media. Running camera version 7.3 I think. The latest. Hands down best SSD for BMPCC 6k.

If you were shooting Q0 did you test with a lens on, and in focus on something ?

If you just recorded the lens cap then the data rates are still very low on Q0

JB

UPDATE to old thread. Problem solved. Want to record 6K @ 50fps all day long at Q0 setting ?

Warning the file sizes are huge. about 28-30G per min. But yes you can record to a SSD at those rates and the BMPCC 6k loves it.

What SSD will do that you ask. I saw this guy take an Inland Platinum 4TB SSD M.2 2280 NVMe PCIe Gen 3.0 x 4 3D NAND Internal Solid State Drive and put it into a cheap asus SSD case : ASUS ROG STRIX Arion Aluminum Alloy M.2 NVMe SSD External Portable Enclosure Case Adapter, USB 3.2 Gen 2 Type-C (10 Gbps), USB-C to C and USB-C to A Cables, Fits PCIe 2280/2260/2242/2230 M Key/B+M Key.

Drive is $479 for 4TB and Case was $57. Both came same day on amazon. I knew just the test. See if that 6k BRAW could choke yet another SSD. What's the point of having a setting no media will support.

formatted it up in exFAT, plugged it into BMPCC 6k usb port and camera said 340 minutes of record time on drive.Saw it no problem. Set it to be primary record drive, Set camera to constant Quality Q0, engage HFR at 50 fps...........I stopped it after 7 minutes of continuous recording because it was getting ridiculous. That SSD is rated at 3400 MB/sec read and 3000 MB/sec write. Best $500 i ever spent for this great little camera. And it's not even approved recording media. Running camera version 7.3 I think. The latest. Hands down best SSD for BMPCC 6k.

Was there any movement in your test shot.
Q0 is a variable bit rate codec. If there was no movement in your test shot then most likely the data rate was below the USB3 gen 1 limit so you would have gotten the same results using a T5 drive?

It was not a real active scene like a soccer game but there was movement from trees and birds. I might add the T5 did it's 3 second thing on same scene before camera stopped.

Agree more testing is required but there is no question it's better than the T5 or CFAST. Wonder if camera is capable of USB C 10gbps/sec.

Movement doesn't matter, BRAW is an I-frame only codec. High detail with high contrast matters.

Movement doesn't matter, BRAW is an I-frame only codec. High detail with high contrast matters.

True Dat...my bad.

UPDATE to old thread. Problem solved. Want to record 6K @ 50fps all day long at Q0 setting ?

Warning the file sizes are huge. about 28-30G per min. But yes you can record to a SSD at those rates and the BMPCC 6k loves it.

What SSD will do that you ask. I saw this guy take an Inland Platinum 4TB SSD M.2 2280 NVMe PCIe Gen 3.0 x 4 3D NAND Internal Solid State Drive and put it into a cheap asus SSD case : ASUS ROG STRIX Arion Aluminum Alloy M.2 NVMe SSD External Portable Enclosure Case Adapter, USB 3.2 Gen 2 Type-C (10 Gbps), USB-C to C and USB-C to A Cables, Fits PCIe 2280/2260/2242/2230 M Key/B+M Key.

Drive is $479 for 4TB and Case was $57. Both came same day on amazon. I knew just the test. See if that 6k BRAW could choke yet another SSD. What's the point of having a setting no media will support.

formatted it up in exFAT, plugged it into BMPCC 6k usb port and camera said 340 minutes of record time on drive.Saw it no problem. Set it to be primary record drive, Set camera to constant Quality Q0, engage HFR at 50 fps...........I stopped it after 7 minutes of continuous recording because it was getting ridiculous. That SSD is rated at 3400 MB/sec read and 3000 MB/sec write. Best $500 i ever spent for this great little camera. And it's not even approved recording media. Running camera version 7.3 I think. The latest. Hands down best SSD for BMPCC 6k.

Just wondering if your still getting decent recording times with this setup. Thanks for any updates!

hi i have the same problem now, do you find a solution?

You have to use higher compression. Despite what people think the T5 should be able to handle, it doesn't. Then also the USB-C port of the PCC6k/4k is USB 3.1 Gen 1 and restricted to a theoretically limit of 5 GBit which translates to 625 MB/s minus 20% protocol overhead. In the end no more than 500 MB/s are available through USB 3.1 Gen 1. And that would be the best case.

@ 50fps
BRAW 3:1 needs 506 MB/s
BRAW Q0 needs 304 to 759 MB/s
ProRes HQ needs 471 MB/s

BRAW 5:1 needs 304 MB/s
BRAW Q5 needs 76 to 217 MB/s
ProRes 422 needs 314 MB/s

I have created an MS Excel and LibreOffice sheet where you can put in the frame rate and it calculates the datarates for 6k, 4.6k, 4k, UHD, 2k, HD for all available codecs and compressions.

Datarates for Blackmagic Camera Codecs v2a 2020.zip

Thank you