URSA data rates

The place for questions about shooting with Blackmagic Cameras.
  • Author
  • Message
Offline

DavidCox

  • Posts: 43
  • Joined: Mon Jan 28, 2013 8:37 pm

URSA data rates

PostTue Sep 16, 2014 1:34 pm

The Ursa tech specs say 880 mbps (megabit per second) for UHD 422 HQ... so is that 108 MB/s (Megabyte per second)?

I'm wondering if the Transcend cards would be fine for ProRes?
http://www.bhphotovideo.com/c/product/1 ... flash.html

It looks as if they handle 2x the throughput required.

Of course, I may be off in my conversion.

Has anyone tried them or have any hands on with those lesser cost CF cards?

Thanks for any response.
Offline
User avatar

rick.lang

  • Posts: 6834
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: URSA data rates

PostTue Sep 16, 2014 3:57 pm

David, Apple cites a target data rate of 884Mbps for 10bit 3840x2160 UHD ProRes 4:2:2 HQ including audio. So at 8 bits per byte, that's 110.5MB/s. Call it 110 or 111...


Rick Lang
Sent using Tapatalk HD
Rick Lang
Offline

DavidCox

  • Posts: 43
  • Joined: Mon Jan 28, 2013 8:37 pm

Re: URSA data rates

PostTue Sep 16, 2014 5:33 pm

Rick,

Thanks.. that's close to what an online calculator gave me. I was using the 880 data rate from the Blackmagic Ursa specs page.

If anyone that's using the camera has any insight on what cards are working well, that would be great.

Thanks,
Dave
Offline

Nigel Daniels

  • Posts: 80
  • Joined: Mon Jun 23, 2014 10:57 pm

Re: URSA data rates

PostTue Sep 16, 2014 5:54 pm

DavidCox wrote:Rick,

Thanks.. that's close to what an online calculator gave me. I was using the 880 data rate from the Blackmagic Ursa specs page.

If anyone that's using the camera has any insight on what cards are working well, that would be great.

Thanks,
Dave



I get mine on Friday. I'm not sure if the Transcend cards will work, however. At least based on what I was told.
Nigel
Offline

DavidCox

  • Posts: 43
  • Joined: Mon Jan 28, 2013 8:37 pm

Re: URSA data rates

PostTue Sep 16, 2014 6:46 pm

Nigel,

Thanks for your reply. I guess there are not very many in use yet.

Cheers,
Dave
Offline
User avatar

Marco Solorio

  • Posts: 116
  • Joined: Wed Aug 22, 2012 3:40 am
  • Location: Walnut Creek, California

Re: URSA data rates

PostTue Sep 16, 2014 7:04 pm

So far we've only been using SanDisk Extreme Pro CFast 2. Certification is still going on for Lexar and Transcend. I have a feeling the Transcend cards will work, but time will tell. Hopefully so, as they're half the cost and double the size, LOL! I have to say, these CFast 2 cards are extremely fast. Even on USB 3, we're transferring 24GB files well under one minute. 4K ProRes HQ at 60 FPS is no problem at all for us on the URSA. Very nice bandwidth speeds here.
Attachments
URSA_CFast2_A52A9126.jpg
URSA_CFast2_A52A9126.jpg (149.72 KiB) Viewed 9602 times
Offline

DavidCox

  • Posts: 43
  • Joined: Mon Jan 28, 2013 8:37 pm

Re: URSA data rates

PostWed Sep 17, 2014 2:40 am

Thanks Marco, I'm looking forward to getting an Ursa. I do many 1-2 person shoots, how's the monitor? Decent color?
Offline
User avatar

Marco Solorio

  • Posts: 116
  • Joined: Wed Aug 22, 2012 3:40 am
  • Location: Walnut Creek, California

Re: URSA data rates

PostWed Sep 17, 2014 5:01 am

Glad to help, David. I actually really enjoy the monitor. I've shot with it outdoors and it's quite nice. Output is much brighter since it's not a touch-screen. And it doesn't hurt that it's 10 inches to help see things. Full 1080 raster is the icing on the cake. All-in-all, well designed IMO.
Offline

Norbert Bielan

  • Posts: 365
  • Joined: Sun Sep 22, 2013 3:52 am
  • Location: New York

Re: URSA data rates

PostThu Sep 18, 2014 1:23 am

The "information note" on BM's website only recommends 120GB Sandisk cards right now. It states:

What CFast cards should I use with the Blackmagic URSA Camera?

The following CFast cards are recommended for 4K ProRes 422 HQ (up to 60 fps)

Sandisk Extreme Pro 128GB CFast card

The following CFast cards are recommended for 4K RAW (up to 30 fps)

Sandisk Extreme Pro 128GB CFast card


Besides the typo (and the grammar error?), is there any reason why the 60GB card wouldn't handle 4K/60P?
Offline

Nigel Daniels

  • Posts: 80
  • Joined: Mon Jun 23, 2014 10:57 pm

Re: URSA data rates

PostThu Sep 18, 2014 2:56 am

Strangely enough I see this company is selling cheap cfast 2.0 cards, with a data sheet touting Ursa compatibility. I called to verify whether or not it's truly supported and was informed that they tested it with the camera. Who knows if that's accurate, however. Here's the link -http://supertalent.com/products/sd_detail.php?sid=263&series=CFast%20Pro . They have a 128gb offering for under a hundred. Haven't looked at the data rates as yet.
Nigel
Offline
User avatar

rick.lang

  • Posts: 6834
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: URSA data rates

PostThu Sep 18, 2014 4:00 am

I don't know, Nigel, but if it sounds too good to be true, it probably is too good to be true.


Rick Lang
Sent using Tapatalk HD
Rick Lang
Offline
User avatar

Marco Solorio

  • Posts: 116
  • Joined: Wed Aug 22, 2012 3:40 am
  • Location: Walnut Creek, California

Re: URSA data rates

PostThu Sep 18, 2014 4:25 am

Norbert Bielan wrote:is there any reason why the 60GB card wouldn't handle 4K/60P?

Only BMD could confirm that for now, but at 4K ProRes HQ 60p, you'd probably only get about maybe 6 minutes on that card? Not really worth it unless ProRes LT or ProRes 422 is okay for what you need to do, then you'll get a substantial increase in space. I'd wait for Lexar and Transcend cards though... cheaper and larger. BMD is testing these cards. I see no reason why the Lexar cards won't pass, and for that matter, the Transcend cards as well.

Nigel Daniels wrote:Strangely enough I see this company is selling cheap cfast 2.0 cards, with a data sheet touting Ursa compatibility.

At only 50MB/s write speeds, I can't see how they're saying this is compatible with URSA. The SanDisk CFast 2 cars writes at 350MB/s as a reference. 4K RAW is about 9 to 10MB/frame and at 24p, that's about 240 MB/s. No way that Super Talent card could work as is. Just like Rick says... too good to be true! ;-)
Offline
User avatar

Marco Solorio

  • Posts: 116
  • Joined: Wed Aug 22, 2012 3:40 am
  • Location: Walnut Creek, California

Re: URSA data rates

PostThu Sep 18, 2014 4:29 am

Oh and BTW... looking at the photo of that Super Talent card (in the data sheet) reveals to me that it is not using a CFast 2 connector but rather, standard CF female pin sockets. Whatever they're touting, that card is not a CFast 2 compliant card at all.
Offline

Nigel Daniels

  • Posts: 80
  • Joined: Mon Jun 23, 2014 10:57 pm

Re: URSA data rates

PostThu Sep 18, 2014 11:46 am

Marco Solorio wrote:Oh and BTW... looking at the photo of that Super Talent card (in the data sheet) reveals to me that it is not using a CFast 2 connector but rather, standard CF female pin sockets. Whatever they're touting, that card is not a CFast 2 compliant card at all.



Hi Marco. There are two offerings from the company. The 'pro' version - http://supertalent.com/products/sd_deta ... Fast%20Pro states that it is 2.0 compliant and compatible with the URSA via their compatibility chart. There aren't many being tested for the URSA anyway. I may order one or two to test and return if not working properly.

Ultimately, I'm leaning towards the transcend cards. I get the impression that they may in fact work.
Nigel
Offline

Norbert Bielan

  • Posts: 365
  • Joined: Sun Sep 22, 2013 3:52 am
  • Location: New York

Re: URSA data rates

PostThu Sep 18, 2014 12:45 pm

Marco - would you know if BM will release compatibility information for Transcend or Lexar anytime soon?
Offline

Blaine Russom

  • Posts: 819
  • Joined: Wed May 01, 2013 2:09 am

Re: URSA data rates

PostThu Sep 18, 2014 1:33 pm

I've used SuperTalent memory for computers before, it's actually reliable.. but thats a whole nother ball game... Does it have reliable speed? Not sure about that. I would feel better with a Sandisk card personally.
MBP Mid-2012 9,1
OSX El Capitan
Dual GPU (NVIDIA 650M 1GB, Intel HD 4000 1GB)
2.6 Ghz Intel i7
16GB RAM, 480GB SSD
Offline

Nigel Daniels

  • Posts: 80
  • Joined: Mon Jun 23, 2014 10:57 pm

Re: URSA data rates

PostThu Sep 18, 2014 2:42 pm

Blaine Russom wrote:I've used SuperTalent memory for computers before, it's actually reliable.. but thats a whole nother ball game... Does it have reliable speed? Not sure about that. I would feel better with a Sandisk card personally.



I agree, Blaine. I had only taken a cursory look at the specs on their page, when I saw that they listed compatibility with URSA, I thought it may have been a viable option. As mentioned above, seems to good to be true.
Nigel
Offline

Norbert von der Heidt

  • Posts: 164
  • Joined: Fri Sep 05, 2014 9:24 am
  • Location: Cairns, Australia

Re: URSA data rates

PostFri Oct 17, 2014 3:01 am

In my humble opinion, the current price of CFast 2.0 media make them prohibitively and outrageously expensive and unless you are in a high end production situation where someone else if paying the piper, they are not worth buying.

I would just recommend to everyone who can, to go out and buy an outboard 4K recorder of their choicem there are already a few to choose from. You'll get a much better bang for the buck, plus you get a great client/director monitor in the process.

Personally, I am waiting for Atomos to release the Shogun 4K recorder in November that uses relatively cheap SSDs or even cheaper 2.5" HDDs. At $2300 (approx) for the Shogun plus $1000 for an Angelbird 632GB SSD =$3300, I could record 4hrs approx ...... instead of getting only 26mins of CFast recording time.

IMHO, CFast are not going to come down in price that quickly as the market is so fantastically small that manufacturers will be keeping artificially prices high for a lot longer than other mass consumer media cards.
Norbert von der Heidt

ELECTRIC IMAGES
www.electricimages.com.au
Offline
User avatar

Robert Niessner

  • Posts: 1069
  • Joined: Thu Feb 21, 2013 9:51 am
  • Location: Graz, Austria

Re: URSA data rates

PostFri Oct 17, 2014 4:37 pm

Norbert von der Heidt wrote:IMHO, CFast are not going to come down in price that quickly as the market is so fantastically small that manufacturers will be keeping artificially prices high for a lot longer than other mass consumer media cards.


Your statement has been already contradicted by reality ;)
http://www.bhphotovideo.com/c/product/1 ... cfast.html

The new upcoming Lexar 256 GB CFast 2.0 card comes at $ 1,300 - that is $ 5,08 / GB
while the SanDisk 120GB Extreme Pro CFast 2.0 Memory Card comes at $ 1,200 - that is $ 10 / GB.

The race to the bottom has already started :)
Robert Niessner
LAUFBILDkommission
Graz / Austria
---------------------------------------------------------------------
Blackmagic Camera Blog (German):
http://laufbildkommission.wordpress.com

Read the blog in English via Google Translate:
http://tinyurl.com/pjf6a3m
Offline
User avatar

rick.lang

  • Posts: 6834
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: URSA data rates

PostSat Oct 18, 2014 11:03 pm

Just one caveat, Robert. The Lexar will be a very popular choice assuming it writes at 450 MB/s and it gets the green light from BMD, but it's not shipping yet. I do agree by the time NAB 2015 rolls around, the cards will be dramatically cheaper than the current offering. Early adopters may feel the pain until then. I check Lexar's site frequently and it always says "coming soon."


Rick Lang
Sent using Tapatalk HD
Rick Lang
Offline
User avatar

Paul R. Williams

  • Posts: 69
  • Joined: Fri Mar 21, 2014 10:51 am
  • Location: Frankfurt am Main, Germany

Re: URSA data rates

PostWed Oct 22, 2014 5:11 am

I purchased two SanDisk C-Fast 2.0 60GB 450MB/s cards for my URSA. Initial tests show that this card does not handle higher frame rates without dropping frames. I then read this footnote on the dpreview.com website article on the SanDisk C-Fast cards
"120GB: Up to 450MB/s read speed; Up to 350MB/s write speed. 60GB: Up to 450MB/s read speed; up to 225MB/s write speed.Based on internal testing; performance may be lower depending upon host device. 1MB=1,000,000 bytes. X=150KB/s."
Blackmagic recommends the 120GB size card. The difference in continuous writing speed was not clear for me before I bought the 60GB cards :(
Paul R. Williams
    BMPC4K, URSA EF 4K, URSA Mini Pro 4.6K (EF/PL)
    Cineroid EVF4-RVW
    Chrosziel MagNum Wireless Lens Control
    Atomos Ninja2, Shogun
    SanDisk SSDs & Lexar CFast
    iMac 27" i7 3.4GHz & NVIDIA GTX 680MX 2GB
Offline
User avatar

rick.lang

  • Posts: 6834
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: URSA data rates

PostThu Oct 23, 2014 4:50 pm

Paul, yes, the 120GB Sandisk is rated at 350GB/s write while the Lexar 3400x 256GB is 450GB/s write,


Rick Lang
Sent using Tapatalk HD
Rick Lang
Offline
User avatar

Paul R. Williams

  • Posts: 69
  • Joined: Fri Mar 21, 2014 10:51 am
  • Location: Frankfurt am Main, Germany

Re: URSA data rates

PostWed Oct 29, 2014 6:55 am

I asked Lexar support for details on continuous write speeds and they sent me this reply:

"Our cards are definitely recommended for the BlackMagic Camera and you can find the specs below:

For the 3400x CFast card:

Capacity - Read - Write
32GB - 510 MB/s - 270 MB/s
64GB - 510 MB/s - 450 MB/s
128GB - 510 MB/s - 450 MB/s
256GB - 510 MB/s - 450 MB/s"
Paul R. Williams
    BMPC4K, URSA EF 4K, URSA Mini Pro 4.6K (EF/PL)
    Cineroid EVF4-RVW
    Chrosziel MagNum Wireless Lens Control
    Atomos Ninja2, Shogun
    SanDisk SSDs & Lexar CFast
    iMac 27" i7 3.4GHz & NVIDIA GTX 680MX 2GB
Offline

Patrick Acum

  • Posts: 41
  • Joined: Mon Mar 17, 2014 5:13 pm

Re: URSA data rates

PostFri Oct 31, 2014 6:40 pm

I received a super talent cfast pro 64gb card today for my URSA. Its listed as up to 50MB/s write, so 400mbps?
Anyway, it was $70 on amazon, so I thought worth a punt.
The good news is, for those interested in 1080 prores 422, it works fine! I filled up a card and didnt have any issues. Plays back fine in camera and played back fine on my aged Imac. I bought the card after reading successful reviews of people using them in ninjas.
Prores proxy is fine
Prores LT fine
Prores 422 fine
Prores 422 HQ stops after about 2mins 30 secs
4k proxy seems to work fine
4k lt works for about 50 secs
4k 422 10 secs
4k 422 a few secs
64Gb lasted something like 40 mins of prores 422. I've found some 128gb on ebay from a seller called Imicros for about $100 a piece...

didnt try raw for obvious reasons!
Offline
User avatar

Paul R. Williams

  • Posts: 69
  • Joined: Fri Mar 21, 2014 10:51 am
  • Location: Frankfurt am Main, Germany

URSA data rates and Media

PostSat Nov 15, 2014 10:05 pm

This information took some time to gather and it would be great if someone from Blackmagic could check on the accuracy. I couldn’t find target rates for CinemaDNG RAW. Trying to analyse the CinemaDNG RAW from the URSA I can only say that I get around 9.2 MB per DNG image file. Due to the compression it´s not clear to me how to understand the original format (8-bit, 10-bit, 12-bit?). However I can use the 9.2 MB to reverse calculate expected data rates (1766.4 Mbps @ 24 fps) and this again does not tally with the URSA manual recording time for 256 GB. So I believe the CinemaDNG RAW data rates are higher than those I have used in the table. This also agrees with my failure to record CinemaDNG RAW at 25 fps without drop-out errors on the SanDisk CFast 2.0 60GB which supports 225 MB/s (1800 Mbps?) continuous writing. Also the indiscriminate use of Mbps, Mbps, MB/s with division based on 1000 or 1024 by different sources doesn’t help things either!

March 17th. 2015
I've updated the data table using the 30 frames/sec. rates given in the URSA Technical Specifications. All other frame rates have data rates calculated proportionately. I have also incorporated the test results for the Transcend CFX650 CFast cards in this forum by BL2 S.r.I. (Italy) http://forum.blackmagicdesign.com/viewtopic.php?f=2&t=27350&p=180226#p181697
Attachments
URSA Data Rates and CFast Cards.png
Updated March 17th. 2015
URSA Data Rates and CFast Cards.png (525.96 KiB) Viewed 6305 times
Last edited by Paul R. Williams on Tue Mar 17, 2015 10:14 am, edited 6 times in total.
Paul R. Williams
    BMPC4K, URSA EF 4K, URSA Mini Pro 4.6K (EF/PL)
    Cineroid EVF4-RVW
    Chrosziel MagNum Wireless Lens Control
    Atomos Ninja2, Shogun
    SanDisk SSDs & Lexar CFast
    iMac 27" i7 3.4GHz & NVIDIA GTX 680MX 2GB
Offline
User avatar

rick.lang

  • Posts: 6834
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: URSA data rates

PostSat Nov 15, 2014 10:48 pm

Paul, while I await seeing your table of data rates, I do think the recording times in the tables in the latest URSA manual have been calculated rather than observed. Generally they are using a rate that corresponds to about 8MB per compressed CinemaDNG image and may not allow for recorded stereo audio. Your observed DNG size over over 9MB is closer to what I'd expect. Now the size of the actual files varies with the complexity of the image by a large amount since a very simple scene like a blue sky is going to be much smaller than a scene full of detail. Then your experience of course trumps the table for the things you find you are shooting. The table is a useful guide but not any guarantee.

In Marco Solorio's post earlier in this thread, he found the DNGs to be 9MB to 10MB. Playing it safe and making the mental math easier, let's assume 10MB frames. For 24fps, you need to sustain writing individual files at the rate of 240MB/s. At 30fps, 300MB/s. The higher capacity CFast 2 cards appear they should do the job. Now some scenes can exceed 10MB/s and the cards need some time to create new records and manage the data cells. For those reasons, if BMD certifies the Lexar 3400x CFast 2 cards, I'd feel comfortable with their media since they seem to have more headroom to cope with variations in scene complexity.

It gets a bit strange when recording raw, since the times for a single complex take may fill one 256GB card. Last night I watched the opening scene of the television series Gracepoint shot where I live. Taking several minutes for a continuous crane shot, it was probably long enough to fill that card. And sadly no card currently would have pulled off Orson Wells' greatest opening shot on film: Touch of Evil (1958).

Rick Lang
Sent using Tapatalk HD
Rick Lang
Offline
User avatar

Paul R. Williams

  • Posts: 69
  • Joined: Fri Mar 21, 2014 10:51 am
  • Location: Frankfurt am Main, Germany

Re: URSA data rates 1.9.9

PostSun Nov 23, 2014 2:44 pm

I've started testing the data rates after the update to 1.9.9.

If I attempt to record 4K RAW at 24p knowing that this will eventually drop frames when the CFast cache is full, I can see in the file folder that in this case my first dropped frame was 1060. This is obvious since that numbered DNG file is missing. In 4K RAW 3:1 24p there is no way to see where the first dropped frame occurred since the file numbering is uninterrupted!

For me, a dropped frame means that the take is only good up to that point. In that case, I wouldn't object to an optional audible warning signal in the headphones and optionally also on the soundtrack so that the exact moment could be localised.

BTW: I know faster CFast media is the real solution - when the price is right!
Paul R. Williams
    BMPC4K, URSA EF 4K, URSA Mini Pro 4.6K (EF/PL)
    Cineroid EVF4-RVW
    Chrosziel MagNum Wireless Lens Control
    Atomos Ninja2, Shogun
    SanDisk SSDs & Lexar CFast
    iMac 27" i7 3.4GHz & NVIDIA GTX 680MX 2GB
Offline

bl2store

  • Posts: 2
  • Joined: Thu Aug 30, 2012 6:21 pm
  • Location: Italy

Re: URSA data rates

PostSun Nov 23, 2014 6:35 pm

Yesterday, we received two new Transcend CFast 2.0 to perform the test compatibility of these memories with URSA.

These results,
tests made with new Transcend CFX650 256GB and 128GB with URSA v.1.9.9:

4K RAW 30fps Failed - Drop-Frames - After 2/3 Minutes
4K RAW 25fps Failed - Drop-Frames - After 2/3 Minutes

4K RAW 3.1 80fps Failed - Drop-Frames - After 10sec
4K RAW 3.1 60fps Failed - Drop-Frames - After 30sec
4K RAW 3.1 30fps Failed - Drop-Frames - After 20min
4K RAW 3.1 50fps Failed - Drop-Frames - After 10min
4K RAW 3.1 25fps Failed - Drop-Frames - After 22min

4K ProRes HQ 80fps Failed - Drop-Frames
4K ProRes HQ 60fps Failed - Drop-Frames

4K ProRes HQ 30fps Test OK
4K ProRes HQ 50fps Test OK
4K ProRes HQ 25fps Test OK

HD ProRes 422 80fps Failed - Drop-Frames - After 1/2 minutes
HD ProRes 422 60fps Test OK
HD ProRes 422 30fps Test OK
HD ProRes 422 50fps Test OK
HD ProRes 422 25fps Test OK

ProRes LT HD 80fps Test OK
ProRes LT HD 60fps Test OK
ProRes LT HD 30fps Test OK
ProRes LT HD 50fps Test OK
ProRes LT HD 25fps Test OK


The highest quality that you can record is the 4K ProRes HQ at 50fps to 80fps only in ProRes LT

__________________

www_bl2Store_com
Offline
User avatar

Paul R. Williams

  • Posts: 69
  • Joined: Fri Mar 21, 2014 10:51 am
  • Location: Frankfurt am Main, Germany

Re: URSA data rates

PostSun Nov 23, 2014 8:01 pm

bl2store wrote:Yesterday, we received two new Transcend CFast 2.0 to perform the test compatibility of these memories with URSA...


Could you please test both cards writing speeds using the Blackmagic Disk Speed Test and publish the results here?

The manufacturers product announcement quoted a writing speed of 370MB/s for the CFX650 and this should have been adequate for all formats and frame rates.

I estimate the highest required writing data rate (4K RAW 3:1 with a sensor frame rate of 80fps) at around 2691 Mb/s = 337 MB/s. I extrapolated this from the recording duration tables in the URSA manual (November 2014).
Paul R. Williams
    BMPC4K, URSA EF 4K, URSA Mini Pro 4.6K (EF/PL)
    Cineroid EVF4-RVW
    Chrosziel MagNum Wireless Lens Control
    Atomos Ninja2, Shogun
    SanDisk SSDs & Lexar CFast
    iMac 27" i7 3.4GHz & NVIDIA GTX 680MX 2GB
Offline
User avatar

rick.lang

  • Posts: 6834
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: URSA data rates

PostMon Nov 24, 2014 5:25 pm

Paul, the claims for a card are usually expressed as "up to" and we don't know the block size used internally to get those speeds. The BMD block size is 128 KB.

The average bitrate may not represent the data demands of the most complex scenes so it's possible that could be a cause of some dropped frames. Hopefully BMD will be updating their approved cards shortly as all tests need to be redone using their latest firmware and using in camera media formatting in exFAT and HFS+.


Rick Lang
Sent using Tapatalk HD
Rick Lang
Offline

Prasenjit Chandra

  • Posts: 5
  • Joined: Mon Nov 03, 2014 4:58 pm

Re: URSA data rates

PostThu Nov 27, 2014 3:29 am

Yesterday I saw in the B&H website that Sandisk 128GB Cfast2.0 is discontinued and 120GB is backordered. Is there any problem in 128GB Cfast2.0 ? I am from India and I got my URSA few weeks ago but still I cant get any cfast2.0 card here. Blackmagic Design should release URSA after the availability of the proper recording media. I am also thinking to buy Atomos Shogun. Is it approved / certified by Blackmagic as an external recorder ?
Offline

Pete Lucas

  • Posts: 45
  • Joined: Thu Oct 02, 2014 2:38 pm
  • Location: Kansas City, MO

Re: URSA data rates

PostFri Dec 05, 2014 8:21 pm

Prasenjit Chandra wrote:Yesterday I saw in the B&H website that Sandisk 128GB Cfast2.0 is discontinued and 120GB is backordered. Is there any problem in 128GB Cfast2.0 ? I am from India and I got my URSA few weeks ago but still I cant get any cfast2.0 card here. Blackmagic Design should release URSA after the availability of the proper recording media. I am also thinking to buy Atomos Shogun. Is it approved / certified by Blackmagic as an external recorder ?


I actually have an inquiry in to Atomos regarding Shogun compatibility. They have not tested it yet, but Shogun will use the 12G-SDI format - they can't say 100% until they actually test one.
"Tell the truth and run." - Turkish Proverb
Offline

Bob Okell

  • Posts: 2
  • Joined: Fri Dec 19, 2014 11:54 pm

Re: URSA data rates

PostSat Dec 20, 2014 12:01 am

What am I missing? these cfast cards dont seem any faster than a good ssd. Why did bmd not continue with the ssd and tbolt port found on the 4k production and stay with modestly priced media?'and if so why not put in a screw in adapter to convert a cfast port into a tbolt outlet?
Offline
User avatar

rick.lang

  • Posts: 6834
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: URSA data rates

PostThu Dec 25, 2014 3:07 am

Pete Lucas wrote:
Prasenjit Chandra wrote:Yesterday I saw in the B&H website that Sandisk 128GB Cfast2.0 is discontinued and 120GB is backordered. Is there any problem in 128GB Cfast2.0 ? I am from India and I got my URSA few weeks ago but still I cant get any cfast2.0 card here. Blackmagic Design should release URSA after the availability of the proper recording media. I am also thinking to buy Atomos Shogun. Is it approved / certified by Blackmagic as an external recorder ?


I actually have an inquiry in to Atomos regarding Shogun compatibility. They have not tested it yet, but Shogun will use the 12G-SDI format - they can't say 100% until they actually test one.


Pete, someone posted a quote from a forum discussion on Atomos in the last few days that claimed the the implementation of 12G SDI may not be consistent for BMD and Atomos since the 12G SDI specification has not been finalized.

Rick Lang
Sent using Tapatalk HD
Rick Lang
Offline
User avatar

rick.lang

  • Posts: 6834
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: URSA data rates

PostThu Dec 25, 2014 3:18 am

Bob Okell wrote:What am I missing? these cfast cards dont seem any faster than a good ssd. Why did bmd not continue with the ssd and tbolt port found on the 4k production and stay with modestly priced media?'and if so why not put in a screw in adapter to convert a cfast port into a tbolt outlet?


The published specs of SSDs mean very little when it comes to determining their suitability for use in video recording and playback in these high bitrate cameras such as the BMD cameras. Even drawing conclusions based on BMD's published usage charts doesn't allow for variations in bitrate depending upon each different scene. The lost likely reliable conclusion is still waiting for BMD to update their approved media lists. It's a challenge to keep these up-tp-date as I believe they do a lot of retesting with new firmware updates that may relate to media (format, recording and playback).

One reason to go with CFast 2 cards is these were among the first cards designed for video that could record 350 MB/s. Personally, I think once the Lexar's come on stream, they'll be very popular as the larger units record up to 450 MB/s. That gives a comfortable margin of safety for any scene hopefully.

A SSD is designed primarily for use in a computer handling different I/O demands, and I'd trust a 450 MB/s CFast 2 card well before I'd assume a 550 MB/s SSD would work as well in a camera.

Rick Lang
Sent using Tapatalk HD
Rick Lang
Offline

Bob Okell

  • Posts: 2
  • Joined: Fri Dec 19, 2014 11:54 pm

Re: URSA data rates

PostThu Dec 25, 2014 5:18 am

Up to is a very unhelpful phrase. Yes sandisk quote up to 350 write for their 120 gb cards but dont specify block size .Their 128 gig card is claiming up to 440 write speed
I checked anand tech and referring to an earlier post that quoted bmd as outputting in 128 k blocks found that a samsung evo 840 ssd of 1 tb could do 374 with a sequential write of 128k blocks from test results .This ssd could write 4k blocks at 428.
Whilst I value your opinion I do want to have actual information.
cfast cards under 2 spec have 2 lanes of sata so there is nothing special about their type.
From a back conversion I calculated bmd is outputting at 325 for 4k
A quick look at shogun showed it could only manage 4k at 30 fps.
The odysseyq is sold with 2k recording and I could only find canon raw at 60 fps for an additional licence and that would require ssd raid. There is no indication ursa is supported for any raw output at 60 fps.
ps thanks for the spreadsheet it helped a lot

Return to Cinematography

Who is online

Users browsing this forum: Jon O'Neill, Ulysses Paiva and 13 guests