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Is G-RAID 320 mini good enough for SD?
Friends:
Most all of my work uses BetaSP captures. I have a dead Media Vault and I’m not going to be able to replace it (can’t get anyone to repair it) for another month. I don’t have heavy workflow, but I do need to work with two (maybe three) streams of SD captures. I borrowed a friend’s G-RAID 320 gig mini Firewire 800. My own disk speed test of his drive showed a read speed of 49.4 MB/s and write speed of 51.9 MB/s. That’s okay, but is it enough?
Here are the questions:
Is this enough speed to have two (or three) streams of SD video (8 bit 4.2.2) playing in FCP 5.1.4, Mac OS 10.4.10 with quad core, 2.5 Ghz processor and 2.5 gigs of RAM?
If this unit is good enough for these streams, keeping in their same line of external drives, is stepping up to 1 TB going to give me the same basic speeds?
I couldn’t locate an online chart showing me necessary MB/s speed for SD video. I knew some of you have this on the tip of your tongue.
Thanks. I need to order something today.
Greg Golden
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10 Replies
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8-bit uncompressed has a bitrate of 90 Mbit/sec. You need at least two firewire drives in a raid-0 configuration to achieve that, or possibly one SATA drive, but even so you wil lbe right on the ragged edge, and you might drop frames when capturing or laying off to tape.
David Roth Weiss
Director/Editor
David Weiss Productions, Inc.
Los AngelesPOST-PRODUCTION WITHOUT THE USUAL INSANITY ™
A forum host of Creative COW’s Apple Final Cut Pro, Business & Marketing, and Indie Film & Documentary forums.
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I don’t have the bitrate on the tip of my tounge, but FCP will tell you it via Item Properties.
And check this out:
https://www.g-technology.com/Products/G-RAID-mini.cfm
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[David Roth Weiss] “8-bit uncompressed has a bitrate of 90 Mbit/sec”
It’s actually more like 200mbps. I think you got that number from Digibeta, which is compressed to 90mbps.FW400 can handle double that (400 mbps). Remember that the AJA I/O does uncompressed SD, and it has the same bus limitation. It’s true, a single non-RAID disk drive from 2-3 years ago would start to choke once it fills up and gets fragmented. I would never edit uncompressed off one of those. But the new drives (750GB or more) are twice as fast as the older ones and could probably handle multiple streams without being in a RAID.
Sean
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A single drive is not recommended for any editing, especially uncompressed.
You want at least a 2bay RAID. I just picked up a sweet little MaxxDigital 2 bay unit that can be configured either FW800 or eSATA and has plenty of speed for uncompressed SD editing and you can replace the drives anytime by just sliding out the sleds and inserting new drives. Makes it great if you want to archive projects and put them on the shelf.
maxxdigital.com or just call them from the number on the website.
Walter Biscardi, Jr.
Biscardi Creative Media
HD and SD Production for Broadcast and Independent Productions.STOP STARING AND START GRADING WITH APPLE COLOR Apple Color Training DVD available now!
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I have a 2bay Firmtek enclosure with 2 500 gig SATA drives in RAID 0 and it does SD and some HD just fine. Total cost was less than 600 bucks.
Have a wonderful day.
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That was the most useful hint I’ve been given all day. My captures with Blackmagic Extreme are 20.2 MB/s 4.2.2 8 bit uncompressed (according to these properties). Thanks! Thanks everyone for your counsel and wisdom.
Greg Golden
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So as a follow-up to this post, if I picked up some internal SATA drives and placed them within my Mac (I know this isn’t the preferred way, but I need a bridge to fill this time/money gap) and raided them, could I expect to be just as successful as external Firewire 800 mini-RAID? This install procedure is new to me, and if anyone could point me to a suggested drive list and RAID striping procedure, I’d be grateful. My son is a Geek Squad manager, so I know he can help to some degree.
Thanks!
Greg Golden
Media Pastor
Mobile, AlabamaGreg Golden
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Heck yeah, forgot about that option. We have 3 750’s in our MacPro at RAID 0, it works great.
Have a wonderful day.
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[Greg Golden] “So as a follow-up to this post, if I picked up some internal SATA drives and placed them within my Mac (I know this isn’t the preferred way, but I need a bridge to fill this time/money gap) and raided them, could I expect to be just as successful as external Firewire 800 mini-RAID?”
Yep. Go to Peter Wiggins’ blog and he shows how to install some extra drives inside the machine and RAID them. He did it last year I believe.
Walter Biscardi, Jr.
Biscardi Creative Media
HD and SD Production for Broadcast and Independent Productions.STOP STARING AND START GRADING WITH APPLE COLOR Apple Color Training DVD available now!
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we are runnning a raid like that for over a year now. it works like a charm. zero heat problems, very high speeds (>200MB/sec), for a fraction of the cost for a “real” raid. Installation: Simple. Put the harddrives in the sleds on your macpro, initalize the raid in the diskutility, done!
But: Backup your files, you never know when it goes down!
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