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Validity of Mac Pro internal RAID
Hi guys,
We’re speccing out a machine for a potential HD job and was wondering how effective a new Mac Pro with three out of its four internal drives set up as a RAID 0 array would function in terms of speed. I know I can get one stream (struggling a little) of uncompressed 10bit SD from a quad 2.5 PPC on one internal SATA drive, so this doesn’t seem out of the question on a brand new fast machine.
I know this is not the system to do 6 streams of uncompressed HD, but for an uncompressed HD job where we can take an offline/online approach, would raiding three internal drives, each on its own SATA bus allow us speed to run … I don’t know … maybe two streams of HD? Like pictures with a credit roll or whatever else we’ll be up against?
Thanks.
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10 Replies
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[Mikey MTC] “for an uncompressed HD job where we can take an offline/online approach, would raiding three internal drives, each on its own SATA bus allow us speed to run …”
Three SATA drives striped as Raid-0 does not have the required throughput for uncompressed HD. It is not the speed of the on-board SATA controller that is the issue, but rather the number of drives available. Six to eight drives are required to produce the sustained throughput necessary to reliably capture and playback uncompressed HD.
Three drives at Raid-0 is however perfectly satifactory for all flavors of compressed HD. Many users use a workflow in which they capture and edit as DVCProHD or Proe Res and then later master to HDCam. Thgis workflow works well with three SATA drives in a Raid-configuration.
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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david is absolutely correct. First off, if you are REQUIRED to do a uncompressed HD job, this means that you have a big budget. There is NO SUCH THING as a LOW BUDGET uncompressed HD job – and if you are the first one to do it, I will have to kill you.
Uncompressed HD requires a drive array that will run consistantly above 200mb/sec. Today, with modern drive arrays, you need a minimum of 4 external SATA drives with a controller to achieve these speeds, and even with only 4 drives, you will BARELY get one stream of uncompressed HD. A RELIABLE system will have EIGHT drives stripped in a RAID 5 (or dare I say RAID 0) configuration for uncompressed HD. With the LOW COST of drive arrays today from companies like Dulce, Maxx Digital, Cal Digit, Sonnet, G-Tech, etc. that cost a fraction of what an HD VTR costs, there is no reason not to purchase the correct drive for what you need. The days of $15,000 drive arrays are over for most of us.
But with that said, David just told you that you can easily do compressed HD (like DVCProHD, or Apple ProRes422) on your 3 internal SATA drives stripped RAID 0. This will absolutely work for you.
ProRes422HQ looks great (it looks just like AVID DNxHD220).Now listen Mikey, I don’t want to hear that you are giving away uncompressed HD post production cheap to anyone – understand Mikey !
Bob Zelin
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Ah, it’s so refreshing to see the Old Bob Zelin returning the pastures!! Mikey consider it a badge of honor to have Mr. Z slap you around in a good way. 🙂
As Bob so eloquently put it, 3 drives striped together are not going to handle uncompressed. 5 drives minimum and I highly recommend a good RAID 5 external array. We run MaxxDigital EVO HD which are 8 drives striped together for over 500MB/s in RAID 5, plenty fast enough for Uncompressed HD and it’s at a price that won’t break the bank.
Other good choices are Sonnet, Dulce, Ciprico and Facilis. Uncompressed HD is not cheap, especially if you want a lot of realtime. It’s not nearly as expensive as it once was, but still not cheap by any means.
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!
Read my Blog!
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Hey Walter, no need to water down Bob’s reply. I’m an audio pro and the audio boards are much more violent than this wonderfully cordial place!
I take everyone’s advice on board and realize that even a single stream of uncompressed HD is too much to ask without a decent external RAID.
OK, plan B: I know this is a subjective thing, but is ProRes’ HQ mode good enough at a professional level to use for a HD product? In our case the end result will be for DVD, TV (HD 1080i at best) and a vsgue chance of a BluRay disk. My opinion is that the HQ mode will be more than enough for DVD and the HD TV, but what about as a source for BluRay? Most reports I read claim ProRes is awesome at this level. I’ve only used it in SD myself.
Thanks.
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[Mikey MTC] “Hey Walter, no need to water down Bob’s reply. I’m an audio pro and the audio boards are much more violent than this wonderfully cordial place! “
Good to know! I’ll make sure the athletic supporter is firmly in place before venturing into the dark underworld that is audio…… 🙂
[Mikey MTC] “OK, plan B: I know this is a subjective thing, but is ProRes’ HQ mode good enough at a professional level to use for a HD product? In our case the end result will be for DVD, TV (HD 1080i at best) and a vsgue chance of a BluRay disk”
You know ProRes is just a weird animal. Works great 95% of the time, but the other 5% is just weird. The codec does some weird things in Color with bad artifacting and sometimes bad interlacing after renders that should not be there. It does some strange things during realtime downconverts as noted in several threads in the AJA Kona forum. I just have not been impressed with the codec to put it into primary production. We only use it at the moment for SD news stories that we deliver to NBC and PBS. We do not use it at all for HD material.
We have been delivering HD network programming to PBS and Food Network HD for the past four years using the DVCPro HD codec as that is what all of our material is originated in. And compared to ProRes I cannot see the difference. It’s something to test and try out in your case, though starting out with HDCAM material, I would probably try Uncompressed and ProRes first.
Keep in mind that ProRes is still a fairly high data rate and you’ll want to make sure that you have plenty of overhead on those three drives before you start the work. As I noted, we have 8TB with 6.5TB useable space in RAID 5. We generally don’t need much more than 3 or 4TB at any given time, but all that extra space ensures we don’t have any drive issues due to the units getting too full. Especially when working in HD, you want to have plenty of extra drive space available to you to ensure smooth operation.
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!
Read my Blog!
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Great reply Walter – thanks for all that.
You have opened my eyes to some potentially uncool things ProRez might get up to.The job I’m talking about is a concert video in a large theatre environment, so the only real visual challenges will be extremes of light rather than tricky movement (drummer notwhithstanding!).
I had considered DVCPro HD as an originating format but hadn’t really considered it as a format to transcode to and edit in.
Food for thought – thanks again.
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Unlike Walter, I use ProRes on all HD stuff and 10bit uncompressed in SD. For our workflow which might be different than your workflow, coming from a formally 10 bit uncompressed HD workflow, ProRes is sweet. Our productions usually contain a fair amount of graphics and we do a decent amount of keying and ProRes has enabled us to keep our productions very clean while also keeping them much lighter in terms of overall bandwidth. I find working with DVCPro HD (sorry Walter, I know it’s your lifeblood and this is not a dig at you) that everything gets trashed. There’s much more noise and compression artifacts when putting our footage through editing/cc/graphics when keeping a DVCPro HD workflow. It’s a great in camera codec, but we don’t use it for more than offline editing.
That’s my 2 cents and take it for what it’s worth.
Jeremy
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Are you using Color extensively yet Jeremy? Just curious what your experience has been with the footage coming back from Color. That’s where we see the most issues whenever we try to use ProRes.
thanks!
[Jeremy Garchow] “That’s my 2 cents and take it for what it’s worth. “
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!
Read my Blog!
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[walter biscardi] “Are you using Color extensively yet Jeremy?”
Dipping our toes in the water so I wouldn’t stay extensively, but have definitely used it enough to make a judgement. Besides some weird XML issues, the footage is totally clean (blows the doors off of any cc in FCP). All of my footage is ProResHQ and rendered back out to ProResHQ, usually 720p and I have tried a bit of 1080i, but have not completed a project with 1080i.
What do you see?
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Most of my clients use DVCProHD, but I am doing the new Nickelodeon show GUTS in ProRes422 (1080i 29.97), and there ain’t no complaints yet. Mastering back to HDW-M2000 for delivery.
To say “is ProRes422 good enough” is the same as asking “is AVID DNxHD good enough” – and since “every major television show uses AVID” (or so they say), then compressed HD is good enough, and DNxHD and ProRes422 have the same compression specs.
Bob Zelin
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