• Blackmagic Design

  Hard drive throughput needed

  Posted by Andrew Weinstein on July 1, 2008 at 9:38 pm

  I have a dual quad core 3.0 Mac Pro. Aside from the system drive I have 2 750 gig hard drives in a software RAID 0, yielding about 1.36 TB. From what I’ve read, this is not really fast enough to capture uncompressed HD through the Intensity card, at least not reliably, and not once the drives start filling up. Can I still capture “lightly” compressed HD with 4:2:2 using these drives or do I need to add a 3rd drive to the RAID. My primary use is for green screening. The BMD site mentions multiple different capture options but I couldn’t find any specifics. So what is the highest level short of uncompressed and would my current RAID set up suffice?
  Lastly, is the Cineform software for the Mac (Nero-HD I think?) a solution for me when used in conjunction with the Intensity card?

  Thank you in advance,

  Andrew

  Margus Voll replied 17 years, 10 months ago 2 Members · 8 Replies
• 8 Replies

• 

  Andrew Weinstein

  July 2, 2008 at 6:53 am

  If it helps, i ran the AJA system test and read/write were both about 137 megs/sec on the 1/3 full RAID.
• 

  Margus Voll

  July 2, 2008 at 2:52 pm

  Hi.

  I got 3x 1 TB Seagate drives and i can get 300 MB / sec with epmty drives.
  I used to have 3x 750 gb and it gave me 2xx MB / sec.

  I’d say definetly go with 3 drives as it is physically faster to write on 3 drives.

  Sise does also mather as i pointed out.

  hope it helps.

  —

  Margus

  https://iconstudios.eu
• 

  Andrew Weinstein

  July 2, 2008 at 3:35 pm

  Thanks for the info.

  How much of a hit does the throughput take when the RAID is half to 2/3 full?
• 

  Margus Voll

  July 2, 2008 at 8:05 pm

  Hi again.

  I can check it out next week on tuesday or so.
  I have about 1 tb free so it qualifyes nicely.

  I’ll test it out and let you know then if you can wait untill then.

  —

  Margus

  https://iconstudios.eu
• 

  Andrew Weinstein

  July 3, 2008 at 5:56 pm

  Thank you.

  That would be wonderful, thank you.

  I’m out of the country starting tomorrow for the next 2 weeks anyway (Costa Rica here I come!!) so no rush on this end. i would be interested to know though, since that is the usual state of my RAID.
• 

  Margus Voll

  July 9, 2008 at 9:07 am

  Hi.

  I did the test today.

  I have 1,21 TB free at the moment and i get this result:

  https://www.iconstudios.eu/internal3tb.png

  Hope it helps and let me know if you have seen this so i can delete the file.

  —

  Margus

  https://iconstudios.eu
• 

  Andrew Weinstein

  July 12, 2008 at 11:50 pm

  Thank you. So, when empty the 3 HD RAID gets 300 megs/sec and when about 60% full you are getting 225-250. Not bad at all. Certainly good enough for capturing and editing uncompressed HD I assume.

  Again, thx for the follow up.

  Andrew
• 

  Margus Voll

  July 15, 2008 at 1:56 pm

  Yes not bad but again 1 TB Seagate disks with 32MB buffer.
  With prorez it is more than sufficent 😉

  Generally it gets you started 🙂

  —

  Margus

  https://iconstudios.eu

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