My HD/2K hardware setup… are 4 disks enough?

[Callum Mclay]

Hi Ricardo

One important thing to consider here, is not just the size or your array, but also the speed at which it runs. You can use the Blackmagic Design Disk Speed Test Utility (installed with your Decklink Drivers) to find out what read/write speeds you will be getting from your RAID.

You can then compare this back to the data rate of footage you intend to edit. At the higher end of uncompressed HD, you will be looking at around 150MB/s.

Generally speaking, a 4 drive RAID 0 should be plenty for most HD work with a Decklink card. 2K however is a different problem, and I would not expect 2K to playback from a 4 drive RAID 0.

As you have the space in that enclosure, i would say 8 drives in a RAID 5 would be good for 2k. You may also get away with 5 drives in a RAID 0, but it may be a little uncomfortable for long captures! It is also worth considering your RAID controller, which will affect the efficiency of the array.

Remember it all comes down to the speed your RAID can provide, the data will always get there eventually, but for real time video we always like speed! Your 4 drives should be great for HD at 1080i, you can sometimes even get away with 3!

In regard to your monitoring needs, generally a HDTV is a great alternative to an expensive broadcast monitor. Esepcially if you only intend to use it for watching your video. If you are doing some serious colour grading work, or need to view 2k i would advise against it, but as a cheaper monitoring solution its a good way to go, depending on your budget.

Callum McLay
Technical Support Consultant
Blackmagic Design EMEA

[Ricardo Ellstein]

Thanks a lot for advice. I’m definitely setting it up, and I’ll let you know how it works out with my particular configuration.

Thanks for the help.

Ricardo

[Bob Zelin]

I disagree with Callum.

4 drives are NOT ENOUGH. to get SUSTAINED playback of uncompressed HD, you need a minimum of 210mb/sec, and you will NEVER get sustained playback from only 4 drives. All modern drive arrays that you see advertised on these forums (look to your left and right, right now), all use EIGHT SATA DRIVES in an external enclosure. However, if you plan on only doing DVCProHD or Apple ProRes422HQ, then yes, 4 drives are enough. MODERN HI SPEED DRIVE ARRAYS with a modern controller card with 8 SATA drives will do over 500mb/sec, and this will be enough for 2K files. I cannot tell you if the Highpoint RocketRaid can perform at these speeds. I have had poor results with the RocketRaid in the past. I am not saying that it won’t work – but it ain’t no ATTO R380, Areca 1221x, or Cal Digit card.

No one “cheaps out” on 2K workflow.

Bob Zelin

[Ricardo Ellstein]

Hi Bob,

Thanks a lot for writing. I’ve double checked the RocketRAID 2322 cards specs, and they’ve published tests using this card running at over 450 mb/s with an 8 disk RAID 0 array. I imagine that a 4 disk array should run at half, or 225 mb/s which should be enough. I also have a RocketRAID card right now (lower end than the one I’ll be buying) and it’s performed very well for a couple of years with SD content.

To be honest, and in part due to your response, I’m going to play it safe buy the cables and enclosures for 8 disks. If the drive underperforms with 4 disks, I’ll just add more until we’re up to speed!

One more thing… you mention that for 2K you need 500 mb/s . I realize there might be something I’m not considering, but from what I gather (considering a similar color space) a 2K frame is 54% larger than a full HD frame. So my guess is that if it takes 210 mb/s for sustained full HD, it would take about 315 mb/s for 2k, and I’d be covered with a 6-7 disk array.

Let me know if I’ve got the math right on this.

Cheers.

Ricardo

[Jon Schilling]

Ricardo.

Hope it’s ok if I chime in to share some info.

If you care & frankly you should, the RocketRAID 2322 that you mentioned is a software RAID card.

Your CPU’s resources is better to be used for your OS & applications & not for RAID computation.

Hardware RAID is really recommended over software RAID, especially for high end editing, which requires more CPU resources.

Jon Schilling | Director of Business Development
CalDigit Inc
phone 714-572-9889 X234
fax 714-572-9881
web http://www.caldigit.com
email jons@caldigit.com
skype cgijon
office 1941 Miraloma Ave. #B Placentia, CA 92870

[Bob Zelin]

Let me chime in, in my normal cheerful self.
What the HELL is wrong with you, Ricardo. You are going to do a 2K job, and you are worried about spending an extra $400 on 2 more disk drives. What the hell are you going to do with the extra $400, when you are doing a 2K job, that will be a budget of over $1,000,000 for the production? Do you actually think that you will do a corporate in house video at 2K, with a $5000 budget. STOP THIS NOW !

Buy yourself a Cal Digit HD Pro, that can serve all of your profesional needs at uncompressed HD and 2K, and stop this nonsense.
And while you are at it, buy a HDLink Pro, and a Decklink HD Extreme.

Bob Zelin

[Margus Voll]

Id go with 16 or more drives even in my array with 2K as you probably need some really fast raid 6 solution as material amount is massive and if you loose it, probably it will be death to your budget and project eny way specially timetable – scanning / converting.

Ferrari does not run without a lot of gasoline 😉

For corporate video HDV should be really sufficent if you know how to make it at its best.

—

Margus

https://iconstudios.eu

[Simon Blackledge]

Pretty sure the 2322 has a HW raid chip on it.. as does the ATTO R380 ?

How can we be sure about this? are there specs to look for ?

S

[Ricardo Ellstein]

Hello everybody,

Well, I ended up buying the configuration I listed in my first post. I was actually going to go for the Caldigit RAID card, based on the comments from this thread, but found out it wasn’t an option in “build it yourself” arrays… it only works with CalDigit equipment, which looks very good, but is at least two times as expensive as what I ended up getting.

Their equipment looks great, and would definitely acquire an array from them for a larger project, but the solution I’m building should work fine for our current needs.

As to what you wrote in your delicate style, Bob, I’ll let you know where I’m coming from. The truth is we don’t all live in the US or Europe (which is where I imagine you’re writing from). Right now I’m in Mexico City, where the rules are slightly different. Here a good sized feature film with mexican A-listers and all the bells and whistles included costs around 1-2M. Budgets are very different this side of the river, Bob.

We get requests for trailers to do trailers and such all the time, but the clients don’t even want to pay for HD… they’d rather work in SD and blow it up to film, which turns my stomach. And yes, some of these people want trailers, and ads for the cinema at $5000, believe it or not. Of course, not all clients are like this, but the amount we charge for a job is drastically different than what you guys get in the US or other countries.

Also, and this is more of a business philosophy… I try to never spend more than I have to on anything I buy. With this configuration I can build myself an 8TB RAID 0 array running at 450 mb a sec for under $2000. It might not be as shiny or pretty, but plug-and-play arrays are retailing for three times as much, so I think it’s a good deal.

Thanks to everybody who wrote. I’ll do some tests when I get all the stuff hooked up next week and post a report on how things are working.

Cheers.

RE

[Margus Voll]

Hi.

As i see you try to build on PC.

I’d get lets say 3ware raid card for sata II and hell of a big case
and build my raid there with my pc.

That’s i have done it few years ago. Ok the expandability was a bit low up to 8 drives but it is a bit cheaper eazyer to build.

—

Margus

https://iconstudios.eu