RAID 0 HD10 bit uncompressed Playback on 3 stripped internal Hardrives
by aaron sheddrick (Aaron Sheddrick)
on
Aug 14, 2008 at 1:26:03 am
I dont know where else I would post this but I wanted to verify if people out there are doing it. Im aware that its more of an RAID question but didnt see a forum.
Here goes:
I have the 3ghz Dual Core Intel Xeon with 4 drive bay slots. (I currently am using 2)
I want to stripe three 500gb drives together in a raid zero to support 10bit uncompressed HD playback in FCP and leave one bay for the boot drive. Is this possible?
Please let me know if there are any other details needed, or if anyone out there is using Xeons in this config.
Re: RAID 0 HD10 bit uncompressed Playback on 3 stripped internal Hardrives by Bob Zelin on Aug 14, 2008 at 2:57:34 am
You may get it to work, but it will not be fast enough for SUSTAINED performance. To get sustained performance for uncompressed 10bit HD (which means you have to play out a 30 minute show, and not a 30 second commercial), you need a minimum of 220mb/sec, and I have found, that with 5 SATA drives RAID 0 (which get this performance), once you start filling up the drive, it drops down to 180mb/sec, and you get DROPPED FRAMES.
So the real answer is no. You need a nice modern RAID 5 8 bay array, shown all over the Creative Cow forums. 500mb/sec is wonderful for sustained performance of 10 bit uncompressed HD, and all these modern drive arrays can do this. But 3 internal SATA drives - no.
Not for a real show. A 10 second test (see, it works !) means NOTHING.
Bob Zelin
ps - use ProRes422HQ - you can use your 3 internal drives, save money, and your client will never know the difference. Dump out your show to HD Cam, and say nothing (I do this all the time).
Re: RAID 0 HD10 bit uncompressed Playback on 3 stripped internal Hardrives by aaron sheddrick on Aug 14, 2008 at 4:41:05 am
Great recommendation on the pro res suggestion. Thanks for the input. The project I have in mind is getting scaled way down for web so pro res is a total fix. But I will be dealing with oddsized screen captures 1154x579 etc. So i guess i gotta see how prores will work in that space.
Re: RAID 0 HD10 bit uncompressed Playback on 3 stripped internal Hardrives by Jordan Woods on Aug 14, 2008 at 4:17:42 pm
more importantly, test how FCP will work with that odd frame size in pro res... we found the hard way that pro res doesn't like true 24, but it is a rare day that anyone works in that frame rate (on purpose). The issue with that didn't rear its head until the timeline was getting filled up, then we were constantly crashing. through a month of trial and error we found it was the true 24 fps that was causing it, but 24fps in any other compression was fine... hmmm, just a thought for pro res with weird frame sizes.
Re: RAID 0 HD10 bit uncompressed Playback on 3 stripped internal Hardrives by Neil Sadwelkar on Oct 9, 2008 at 5:00:18 pm
[Jordan Woods]"pro res doesn't like true 24, but it is a rare day that anyone works in that frame rate (on purpose)"
Actually if you're in a PAL country and making an HD master out of film-based material you would ALWAYS work at true 24 fps. And on purpose.
We have seen these problems in true 24fps and we continue to see FCPs inability to correctly play 24 fps into 25 fps without jittering - but that's another story.
And you're right 24fps in Apple ProRes is funky. But then the whole world is NTSC, right?
