[yarnman]

Hey Guys,

Can I get some feedback about which RAID configuration to build for video editing?

I am looking for reliability, but really don't know what I need. I have been recommended to use 8 drives for HD editing. If anyone has experience with this and it's working for you, please let me know.

[continuum]

How much throughput do you need, and which controller will you be using?

Running multiple RAID1's or RAID10's would be the most reliable, probably, and fastest, but I don't know if you find it desirable to take a 50% capacity hit in your situation for the optimum performance and reliability?

[yarnman]

1200 Mb/s will probably be the max throughput I will need.
I haven't pulled the trigger on the parts...3Ware 9500S-8 8 ports SATA 150 Raid Controller Card, It's PCI, will it work?
I'm looking for optimum performance and reliability. Capacity is of secondary importance, I suppose.

This post has been edited by yarnman: 28 January 2008 - 05:15 PM

[stevecs]

1200Mb/s are you sure that's right? (~140MiB/sec?) If so you'll need a decent # of drives to get a sustained speed of that over the entire array. If you're writing to the array (opposed to say an initial load of video content and then do reads from it) you want raid 10 generally. I wouldn't use raid 4/5/6 unless you get a good high-end card and can make sure you're only doing large (full stripe width) writes to avoid the write hit.

You don't want a PCI card here at all as you won't reach those speeds. You need to have PCI-express or PCI-X. As for the drive interface SATA-150 is fine though you may want to get one w/ SATA 300 if possible. You won't be sending more than 150MiB/sec to the drive anyway as it can't keep up at that rate, that's mainly for burst traffic which you shouldn't really have much of. Depending on the drives and how they fall off in transfer rates from outer-inner tracks you're talking at least 4 drives, though I would be very iffy that that would work when you reach the inner tracks, probably would go w/ 8.

RAID-10 is the 2nd highest reliable format Basically in order of reliability for the subsystem it's raid 0, raid 3/4/5, raid 1/10, raid 6, then you have multilevel raids (technically 10 is multilevel, just put it here as most implementations of raid-10/1E are limited to the same # of drives (32 max usually)) as the others, (raid 100 would be the next multi-level area for that).

[yarnman]

Thanks---I think the throughput is right if I am understanding "Rick's HD Primer" chart correctly?

http://library.creativecow.net/articles/ge...iere-pro-HD.php

Frame Size Type Mbps GiB per hour

1920 x 1080 8-bit 4:2:2 24 fps 795 350
1920 x 1080 10-bit 4:2:2 24 fps 994 437
1920 x 1080 8-bit 4:2:2 30 i fps 994 437
1920 x 1080 10-bit 4:2:2 30 i fps 1243 546

Can you recommend a card and drives that you have had good luck with? Also a guide for building?

[student]

what programs will you be using? a lot of software companies recommend setups for their particular software. adobe for instance makes these recommendations for premier:

http://www.adobe.com...ere/systemreqs/

This post has been edited by student: 30 January 2008 - 12:15 PM

[yarnman]

what programs will you be using?

I'm using Premiere Pro CS3 and the rest of Production Premium. I used the Adobe guidelines when I built the system, save the SCSI disk array. It does not perform well with the 7200 rpm drive for video and I'm only using SD, not HD. So I guess going a bit over the top will prepare the system for the future (how much better can the technology get than HD?) but I was thinking of keeping the cost down and storage up with SATA drives instead of SCSI.

[student]

2 sets of audio and video scratch disks.

1)
RAID0 2 disk 15,000RPM SCSI array as a Captured Video scratch
2)
RAID0 2 disk 15,000RPM SCSI array as a Video Previews scratch
3)
1 Sata disk for Captured Audio scratch and storage
4)
1 Sata disk for Audio Previews scratch and storage
5)
Media Cache? I don't understand how Premier Pro will use this so can't really help spec a disk. I think a Sata disk will be fine as the Video scratch files are the real bandwidth hogs.
6)
DVD encoding if you create DVD's. Probably won't need more than a SATA disk.
7)
1 Sata Project file disk
8)
1 Sata System and Program file disk

I don't know exactly what your work flow will be like but generally you want to seperate Source (Capture) and Output (Preview / Render)Data to seperate RAID 0 volumes that aren't used for anything else.

You want your project files to be on another seperate volume.

You want system (OS) and program files to be on another seperate volume.

That makes a minimum of 6 disks in 4 volumes.

http://livedocs.adobe.com/en_US/PremierePr...88DDE57377.html

[student]

If you want to create SATA RAID 0 arrays for video capture you will need to add another disk or two to each array depending on the disk you go for. See the storagereview database for minimum transfer times and then multiply as necessary. However, 15,000RPM SCSI really is the way forward as scratch disks really benefit from fast access times.

[stevecs]

yarnman, on Jan 30 2008, 09:55 AM, said:

Thanks---I think the throughput is right if I am understanding "Rick's HD Primer" chart correctly?

http://library.creativecow.net/articles/ge...iere-pro-HD.php

Frame Size Type Mbps GiB per hour

1920 x 1080 8-bit 4:2:2 24 fps 795 350
1920 x 1080 10-bit 4:2:2 24 fps 994 437
1920 x 1080 8-bit 4:2:2 30 i fps 994 437
1920 x 1080 10-bit 4:2:2 30 i fps 1243 546

Can you recommend a card and drives that you have had good luck with? Also a guide for building?

Yeah, that's right, I've mainly done DV work so I haven't needed to hit the higher req's for HDTV yet. Anyway, the first big question is what is your tolerance for availability? Ie. If your array dies with all your work on it, is that a big issue? Will you miss a deadline or what is the hassle of re-doing all your edits? That will indicate if you want to use a RAID0 (no fault tolerance) or something else.

From those numbers you'll need about 4 drives as a minimum and pretty good/fast ones like the seagate 7200.11's in a raid-0 to reach your speeds across the entire array. The seagates are decent at the outer tracks but after about 10% in the performance starts to drop (from about 100MB/s down to about 50MB/sec) So to get the minimum of ~155MiB/sec you need 4 drives.

Now for reliability you can do raid-10 which would be the cheapest in hardware you'll need 8 drives to do that. You can do other raids (3/4/5/6) but you'll need more drives but also spend a lot more for the raid card. Raid 3/4/5 for every stripe written at the OS level turns into 2 reads/2 writes at the array level, with raid 6 that's 3 reads/3 writes. Now in your case you should be writting full stripe widths but still you'll have a penalty so I'd roughly say perhaps 5-6 drives needed if you had a good raid controller for 3/4/5/6 controller would be something using the IOP341 chipset so like the areca 12x1 line or the 1280 et al.

personally I'd probably go with a raid-10 build with 8 drives that will give you what you need for writes, and give you better access for reads which will come in handy when you're doing edits and multiple overlays.