Blackmagic Forum

Hi all!

I was super excited to receive my Pocket 4K yesterday, but I've had BIG PROBLEMS recording to new SanDisk Extreme Pro UHS-II SD cards -- the SD cards pictured in the Blackmagic marketing (see below). While shooting at 23.98, some formats drop frames almost instantly (to be expected with Raw), and some formats drop frames a little later, but ALL formats drop frames. Every single one. Even ProRes Proxy HD. I've tried multiple cards, fresh batteries, and even different lenses (just for kicks). I've formatted the cards in the camera, and then on a Mac. Nothing works. Not a single recording without dropping frames. The cards are new, purchased from B&H. I should also point out that recording to SSD works perfectly.

I've notated the seconds-to-failure in a chart that I've attached below. The times don't even make sense in some cases (i.e. ProRes Proxy HD dropped out almost a minute sooner than ProRes Proxy UHD).

Has anyone had good experiences with this camera & card combo, or can anyone tell me why this isn't working? Yes, I know BM hasn't published a new list of approved SD cards, but considering they use these cards in their marketing, surely they should be able to record SOMETHING.

Thanks in advance!

Taz, have you verified with Sandisk that the cards are legitimate which is done by identifying the serial numbers on the cards.

And if they are legitimate, then there may be a problem with the firmware on the card which doesn’t match the firmware on the cards tested by BMD. Sandisk has changed firmware in the past on cards that had been approved by BMD so that the newer firmware did not work well with BMD cameras.

We are still waiting for BMD to publish the list of cards approved for the BMPCC4K.

If they are legitimate and the firmware has not changed from what BMD worked with, then the card(s) nay simply be faulty and propbably Sandisk or the dealer will exchange them if you bought them new.



Sent from my iPhone using Tapatalk

I've shot for several days at ProRes HQ UHD on two Extreme Pro V30 95MBs cards.
I'm guessing these are bad cards if the camera is working fine other wise.

If you can't test the cards in other cameras on hand, try them with the Blackmagic disk speed test utility. If you get through that one, try copying files to them.

Eliminate the possibility of defective cards, and that at least narrows the field.

rick.lang wrote:Taz, have you verified with Sandisk that the cards are legitimate which is done by identifying the serial numbers on the cards.

Hi Rick! I haven't checked authenticity yet. Going to call SanDisk about that tomorrow.

rick.lang wrote:And if they are legitimate, then there may be a problem with the firmware on the card which doesn’t match the firmware on the cards tested by BMD. Sandisk has changed firmware in the past on cards that had been approved by BMD so that the newer firmware did not work well with BMD cameras.

Ha! Just when you thought it was tough finding a card that works... they might change the card. Nutty.

rick.lang wrote:We are still waiting for BMD to publish the list of cards approved for the BMPCC4K.

I spoke with BH Tech support today. The fellow I spoke with said he's expecting that list to go up within the next couple days. Fingers crossed!

rick.lang wrote:If they are legitimate and the firmware has not changed from what BMD worked with, then the card(s) may simply be faulty and probably Sandisk or the dealer will exchange them if you bought them new.

After calling SanDisk tomorrow, I'm going to contact B&H to see about returning the cards. It's been over 30 days, but I'm hoping they play nice considering how much money I've thrown at them over the past year.

Jim Giberti wrote:I've shot for several days at ProRes HQ UHD on two Extreme Pro V30 95MBs cards.
I'm guessing these are bad cards if the camera is working fine other wise.

Hi Jim! Thanks for the reply. I posted this same question over on the BMCUser forums. A couple folks over there also mentioned the 95mb v30 cards as working. Good to know. Going to try to return mine.

John Paines wrote:If you can't test the cards in other cameras on hand, try them with the Blackmagic disk speed test utility. If you get through that one, try copying files to them. Eliminate the possibility of defective cards, and that at least narrows the field.

No other cameras handy, but I did run the BM Speed Test. Speeds looked ok. Then I ran the AJA speed test since that app provides a graph of speeds over time. Looks like some significant data dips during the write. Have a look!

I had no experience of that AJA test, but tried it on a reliable 32gb 95mb type 1 SD card (but not tested in a BMPCC 4k). There are no dips to zero, as in your results (and once it starts up, deviations from maximum rates are very small). which would seem to explain the dropped frames. Maybe someone else will try it on cards known to work.

That AJA graph tells the tale. Although the average of 164MB/s may get you by in some cases, those dips down to near zero are when you drop frames I would think. Interesting to hear what Sandisk can tell you. Your vendor may offer to exchange them, but we’d love to know why they are failing.

I wouldn’t think B&H Photo would be buying illegitimate cards! So I’m thinking a firmware issue.

Sent from my iPhone using Tapatalk

Especially compared with the original HD Pocket, I've been pleasantly surprised by how forgiving the new Pocket 4K is, when using old cards with write speeds that seem to even undercut the published UHD ProRes bitrates. For example, I've shot UHD at 29.97fps into ProRes 422, onto an old Transcend UHS-I U3 card that's rated for a maximum 60 MB/s write speed, and I got no dropped frames. At the other end, just to be safe, I got a UHS-II card with a V90 rating, and of course no worries there. But a cheaper UHS-II V30 card is starting to look tempting, for higher capacity.

I do find that after stopping recording, there's a significantly longer delay before the buffer is finished flushing out, so it looks like Blackmagic engineered a generous buffer to create a tolerance against slow flash memory.

I will use M.2 NVME USB-C box. If I got my pre-order and hope It's work fine. this result from connect USB-C gen 2.

Hope you post back when your drives are connected to the slower USB 3.1 Gen 1 camera port. I’ve been curious about how M.2 drives will perform, but I’ll likely go with Wise portable SSD subject to BMD’s recommendations.

So, with these SSD speeds the pocket should not record 4k RAW lossless 50p (it should be 453MB/s).
When you try this M.2 SSD on the pocket, try to make this recording, please.
I was told instead that a CFast did lossless 50p (60p no way, too much bandwidth for Sata bus).

rick.lang wrote:That AJA graph tells the tale. Although the average of 164MB/s may get you by in some cases, those dips down to near zero are when you drop frames I would think. Interesting to hear what Sandisk can tell you. Your vendor may offer to exchange them, but we’d love to know why they are failing. I wouldn’t think B&H Photo would be buying illegitimate cards! So I’m thinking a firmware issue.

Yes, those dips are mighty troublesome. I'm sure that's the problem.

I contacted SanDisk just to make sure these cards were not counterfeit. Haven't heard back yet. From what I can tell (based on details I've found online), the cards are legit.

Thankfully, B&H has agreed to take back the two cards and issue a full refund, despite the fact that I purchased them over 30 days ago. Whew! Putting that cash back in the bank until we all know what works.

visalapol wrote:I will use M.2 NVME USB-C box. If I got my pre-order and hope It's work fine. this result from connect USB-C gen 2.

I'd LOVE to hear how it works out for you. Keep us posted!

Again, yet another example of buying accessories that may, or may not work, before you have the camera, or at least, the BM recommendations on SD cards. Never a good idea.
Cheers

Denny Smith wrote:Again, yet another example of buying accessories that may, or may not work, before you have the camera, or at least, the BM recommendations on SD cards. Never a good idea.
Cheers

Well, sorta no, actually the opposite. This whole thread started from how a nearly-official, super-fast card exceeding the camera's specs didn't work, whether defective or some other reason. Meantime I've noted that the camera is extremely forgiving with surprisingly slow cards at the UHS-I Class U3 level.

Somewhere in the middle, between paying the maximum amount for the best option in the universe, and slumming it, is just to get a modest spread of anecdotally as well as officially diagnosed compatible cards, but also always having a backup plan within arm's reach. Waiting for some "official list" will only slightly protect you against loss.

Bear in mind, the absolute only card that the prior Pocket could officially use, was the most costly on the market (Extreme Pro, pre-UHS-I). Then we all figured out which other ones worked, and made stuff.

Yes, nothing replaces doing your own testing for how each part will perform in your required situation.
But this requires you to actually have the camera, which is where I was coming from, buying accessories before you actually have the camera. Testing bits yiu a,readymown is good also, then you have a better idea of what you need to buy.
Cheers

When I’ve tested my CFast 2 cards, I run through all the codecs beginning with the fastest frame rates and work my way down the table BMD has for maximum frame rates. It takes awhile as I’ll record for up to three minutes. BMD’s tests are much more thorough.



Sent from my iPhone using Tapatalk

Anyone tried a UHS-I card (the best at 95MB/s) recording Prores 422 HQ @25fps (91MB/s)?

On other system I'm connect A motherboard USB-C result is the same.

Thanks for that. So the choice of USB 3.1 Gen 1 isn’t the end of the world as a connection for the BMPCC4K.


Sent from my iPhone using Tapatalk

No, it's not always like this.
That result is strange, a M.2 pci-e SSD is way faster than that and also the USB-C bandwidth gen2 is way capable of at least double speed (considering overhead).
I saw other tests with higher transfer rates on USB-C 10Gb/s.
It should be something wrong there, or with M2 SDD (it seems like a Sata SSD) or with USB-C Gen2 MB...
Instead for USB-C Gen1 is normal datarate.

For example here you can see USB-C Gen2 @771MB/s write:

https://www.pcworld.com/article/3058320 ... ld-be.html

I have here for my mobile editing a Netstor NA611TB3 with a 2 TB Samsung 970 evo over 40 GBit Thunderbolt 3. It read/writes at 1.500 MB/s. AFAIK it won't work with USB-C-only devices, but would have been pretty cool to test out.

For these prices on the EgoDisk series (Elite and normal versions), I'm just going all-in on C-Fast. Not bothering with slow 300MB/s SD Cards...

I use the Elite Pro's (595MB/s) on my Ursa Mini Pro and have never had a dropped frame. EgoDisk tests every format on all BM cameras, so I wonder why they aren't in the approved list? I'd be happy to do any testing on my end.

David, yes, on Ursa Mini Pro you can do all datarates except RAW 4,6k lossless @60p (you must use 2x CFast). I don't know if you can do Apple ProRes 444 XQ @60p (it's 500MB/s), have you tried it?
But I think Egodisk CFast can't record 4k RAW lossless 60p on the pocket 4k. That is 544 MB/s, so *in theory* inside their declared range.
I would doubt it, even with those declared specs...
They say *upto*, but the real speed should be way lower: I think it's really the SATA bus can't handle that datarate with the overhead.
If you have the possibility, it should interesting making this test.

That is my take also David, for the small price difference between SD UHSII cards and CFast 2.0, why mess around with the s,owner and more fragile SD cards. I plan to use my SanDisk CF cards on my PC4K.
Cheers

@visalapol
Check out also the USB-C cable: even if they declare them Gen2 capable, it's not always true, especially with the long ones: they can't make a correct Gen2 connection, so they swtch to Gen1 speed. I tried some of them and I saw some failed to do it.
With shorter ones it should be easier to find a good one.

Vincenzo Ferreri wrote:Anyone tried a UHS-I card (the best at 95MB/s) recording Prores 422 HQ @25fps (91MB/s)?

I have used both a SanDisk Extreme Pro UHS-I V30 64GB and 128GB card and they write UHD 25p ProRes 422 HQ without a problem.

So... is there a list of approved SDDs, C-fast cards, or SD cards yet?

Vincenzo Ferreri wrote:No, it's not always like this.
That result is strange, a M.2 pci-e SSD is way faster than that and also the USB-C bandwidth gen2 is way capable of at least double speed (considering overhead).
I saw other tests with higher transfer rates on USB-C 10Gb/s.
It should be something wrong there, or with M2 SDD (it seems like a Sata SSD) or with USB-C Gen2 MB...
Instead for USB-C Gen1 is normal datarate.

With respect to M.2 drives, I believe the USB-C implementation on the BMPCC 4K needs to support the PCI-E (PCI Express) bus interface to achieve the very fast read/write speeds that M.2 drives are capable of. If it only supports the SATA bus interface, the cost / performance ratio may favor C-Fast cards, at least at 256GB or less.

Very interested to see real-world performance numbers with M.2 drives as some of the early commentary about SSD performance has put a dose of reality into possibly over-optimistic hopes for recording 4K RAW

Crossing my fingers for PCI-E support from the USB-C port.

Yes, but I think it has not. Because it's a Gen1 USB-C, so they thought only at Sata SSD...

Robert Niessner wrote:

Vincenzo Ferreri wrote:Anyone tried a UHS-I card (the best at 95MB/s) recording Prores 422 HQ @25fps (91MB/s)?

I have used both a SanDisk Extreme Pro UHS-I V30 64GB and 128GB card and they write UHD 25p ProRes 422 HQ without a problem.

Thank you.
Because I saw some speed tests of these cards and they reached at max only 86MB/s. Infact the 95MB/s is only at reading, the write is *upto* 90MB/s, but the real speed seems a bit lower.
Such as here:
https://lensvid.com/gear/lensvid-exclus ... mory-card/

Maybe the prores 422 HQ 91MB/s it's only the peak and not a constant bitrate or cards perform better on the camera than the reader on a pc.

Vincenzo Ferreri wrote:Anyone tried a UHS-I card (the best at 95MB/s) recording Prores 422 HQ @25fps (91MB/s)?

3 posts up from yours.

And NVMe is overkill: nothing the Pocket 4k records can saturate that spec's distinction.

And the camera's buffer is extremely forgiving.

Vincenzo Ferreri wrote:Thank you.
Because I saw some speed tests of these cards and they reached at max only 86MB/s. Infact the 95MB/s is only at reading, the write is *upto* 90MB/s, but the real speed seems a bit lower.
Such as here:
https://lensvid.com/gear/lensvid-exclus ... mory-card/

Maybe the prores 422 HQ 91MB/s it's only the peak and not a constant bitrate or cards perform better on the camera than the reader on a pc.

I just had a look at the bitrates of the recorded footage: it is 93 MB/s on average.

And I did a test of 30p UHD ProRes HQ and after 22 seconds I get a dropped frames warning.

So 25p seems very close to the limit with those cards.

focuspulling wrote:And NVMe is overkill: nothing the Pocket 4k records can saturate that spec's distinction.

I agree that NVME SSD is overkill for the pocket. There is only one format you will need it: 4k RAW lossless 60p. Anyway, with RAW 3:1 or BRAW you can record 60p at excellent quality.
Instead I would have put USB-C Gen2 even only to transfer files to a pc without removing cards at half the time. Nowaday Gen2 is anywhere, why adopting lower specs... Nothing terrible, of course, just thinking the best options.
The same goes for a NVME SSD: you will get no bonus on the pocket, BUT when you will connect to a pc you can benefit of the double speed of USB-C in copying. If prices arent' very different from external Sata SSD, I would go NVME.

Vincenzo Ferreri wrote:

focuspulling wrote:And NVMe is overkill: nothing the Pocket 4k records can saturate that spec's distinction.

I agree that NVME SSD is overkill for the pocket... you will get no bonus on the pocket, BUT when you will connect to a pc you can benefit of the double speed of USB-C in copying. If prices arent' very different from external Sata SSD, I would go NVME.

All good points. When the Wise Portable SSD is released (RSN), folks will be able to verify that the USB 3.1 Gen 2 device transfers at a higher data rate when connected to an appropriate computer. My iMac 27” 2015 is limited to Thunderbolt 2 and USB 3.0 5Gbps though AFAIK. I’d still buy the faster drive though because the drive may outlast the computer.


Sent from my iPhone using Tapatalk

UPDATE: FOUND WORKING SD CARDS

After returning the SanDisk SD cards to B&H last week, I purchased a new pair of cards on Amazon. Specifically, the Angelbird AV PRO SD 128GB SDXC UHS-II U3 Class 10 V90. They're working like champs so far, and at $350 for the pair, they're about $70 less than I paid for the SanDisk cards.

I've run a few tests, and here's what I've found so far (your mileage may vary!):

These SD cards CAN capture 4k Raw at 23.98. I did not try 25 or 30. Naturally, the cards can not handle Raw at 60p (including 4:1) at 4k or UHD. No surprise there. They CAN capture HD Raw at 60p if that matters to you.

I had mixed results recording 4k ProRes HQ at 60p. After formatting the card in-camera, and trying to record 60p, frames would drop within a few seconds. However, things seemed to work perfectly when I tried recording again. I was able to repeat this pattern a few times (format the card, 1st attempt failed, 2nd attempt worked). Strange! ProRes 422 60p worked just fine.

BMPCC4K Review & Guide #4 "Media" SSD CFast SD Tests Blackmagic Pocket Cinema Camera 4K

Not sure if this has been posted on the forum yet.

Looks like the Wise cards are released mid-October as planned.


Sent from my iPhone using Tapatalk