• Dear Simon + All,

    Some preliminary results for you. 
    Recording four channels of LFG-4 to disk:
    Mac OS 10.6.8
    MacPro 2 x 2.8 GHz Quad-Core Intel Xeon
    RAM: 4GB 800 MHz DDR2
    7200 RPM Drive: FPS = 17, Cycles = 55, Resulting Clip FPS = 21
    **10000 RPM Drive: FPS = 30, Cycles = 106, Resulting Clip FPS = 29.42**
    SSD Drive: FPS = 11, Cycles = 41, Resulting Clip FPS = 12,26 (!!!!!!!!!!!!)
    Now, I have to throw in lots of exclamation points next to the SSD drive. Does anybody have any theories as to why the SSD would be the **slowest of all**??? Is it because reading is super fast, but writing is worse than a regular drive. Or????
    [EDIT: search for "ssd drive write speed slower than normal drive" (without quotes.) A lot of entries appear... so it appears some further research on SSD write speed will be necessary.]
    But the main point, as you can see, is that with a fast drive, you can do the capture.
    I'll get a full report with record and play speeds later. But that's the initial feedback
    Best Wishes,

  • Hi Mark,

    I guess answer is yes, but are you testing all the drives on the same bus ( what kind? )?
    What's your SSD ? it should be definetly faster ! Read and write are normally fast.
    Would you run a speed test ( blackmagic software ) on each drive ?

  • Hi Mark

    Thanks you for taking the time to test this and fantastic news that it is possible to do the capture. I'll research the SSD issue further... 

  • Has anyone any experience of using isadora with multiple Blackmagic Intensity Pro cards in a single mac pro? I suspect that Isadora might not recognise them as individual inputs as they are the same model?? The Blackmagic website says this. If it works I was thinking that perhaps buying 4 Blackmagic cards with HD capability might give me more felxibiltiy for future projects than an SD LFG4.


  • Dear Simon,

    Well, I can tell you that the Blackmagic Deck Link Quad shows up as four individual inputs. (I haven't tested four at a time though...) Because this card is essentially four Deck Links in One,  I suspect that multiple Black Magic cards will show up as separate devices. But I cannot say with totally confidence without trying it.
    Best Wishes,

  • Black Magic support emailed the following about multiple Intensity Pro cards in a Mac Pro:

    _'I am afraid but we do not certified this software for your kind of workflow - we certified the use of only one card a time per system. However we are aware of people using multiple card within their system, using software like Wirecast, Softrone, BoinxTv. Again, we do not certified them and we can not guarantee that this configuration is going to work as expected.'_
    ...not much help really so I'm trying to find a supplier that will test it before I buy.
  • Beta Platinum

    Might be worth contacting Anthony Hammond from jigsaw (UK based) he is currently working on a similar thing and he is aware of isadora and it configurations. He generally has access to blackmagic hardware, macs and Isadora, etc


  • Thanks Graham I'll try Jigsaw.

  • Dear Simon,

    Thing is, I have the DeckLink Quad, and thus I should be able to try it -- problem is, it only accepts SDI input, which is kind of an unusual beast. What I did try was to capture from the output of the Deck Link back in to one of it's inputs -- that works, no problem. And I can definitely verify that all 4 inputs (and all flavors of those inputs [e.g., NTSC, PAL, HD, etc.]) appear in the Live Capture Settings dialog. What I can't do is try a 4 way simultaneous capture.
    But, in theory, you can do it with the Deck Link Quad. And like I said, that likely means separate Deck Link cards as well.
    Best Wishes,
  • Beta Platinum

    Dear Simon,

    To follow-up on Mark's post -- I was able to do some capture tests of 3 streams a few months ago with the same deck link quad card and had somewhat mixed results. With 3 streams I would see a significant number of dropped or duplicated frames, and/or bad artifacts.

    I don't have the quad handy currently but I'd be happy to pass my test notes on to Mark in case recent changes in izzy may have helped out with the dropped frame issue.