RAID 0 for HD-SDI uncompressed pci-x recording.

[GideonKiers]

Hi there, a bit off-topic but might still be interesting to some.

I'm trying to compile a system which will enable the recording of the (realtime) DVI output of another computer.

The recording machine will be a dualprocessor 2.5 PCI-X machine.
Capturing card for HD-SDI will be either the AjaKona LH or the Decklink HDPro.

Btw. the conversion box is the Matrox MFO -- http://www.matrox.com/video/products/mxo/home.cfm

Will a RAID0 system like this be sufficient ?

1x http://www.sonnettech.com/product/fusion500p.html
1x http://www.sonnettech.com/product/tempo_sata_x4p.html
5x http://www.zipzoomfly.com/jsp/Produc...uctCode=101537
or
5x http://www.zipzoomfly.com/jsp/Produc...uctCode=100600


thanks,

[samsc]

if you are doing this for real- you need to follow the advice of the real hd video pro's

the decklink support pages have some hints:

http://decklink.com/support/detail.asp?techID=62

Recommended disks for building HD disk arrays are currently the Seagate Cheetah Ultra-320 10k.6, Ultra-320 15k.2 or the Maxtor Ultra-320 10k drives. We don't recommend Ultra-160 drives for uncompressed HDTV work.

We recommend 8 x 10k drives or 6 x 15k drives when building an array. However, you can go as low as 6 for 10k and 4 for 15k; however the extra disks will help improve performance as the drives fill to capacity.

[GideonKiers]

Mmyes we're pretty serious about this. The idea is to end up on 35mm. I've been looking around for the MB/sec needed for recording a 4:2:2 HD-SDI stream but havent been able to find it really. Of course we would like to order the scsi disks and cards, but as this is an artistic project rather than a featurefilm our sources are somewhat limited. Btw, the software for generating the video will be and has partly been allready written by us, using max/msp and especially jitter. Mostly opengl work.
I'll research some more and keep you posted. We're in holland so the sources are a bit limited in terms of hardware and knowledge.

[samsc]

you want to record hd-sdi - without spending any money?

then think about what you are actually trying to do artistically - and what is necessary..

Mike Curtis runs a website for people trying to do this kindof thing.
http://www.hdforindies.com/

[samsc]

to do this kindof thing- cheaply- you need to be aware of the quite large differences in performance between different hard discs - nothing to do with catalyst or any other software.

it is a combination of the interface type and hard disc choice that makes this work.
you need a fast interface - and fast hard discs.
And to get anywhere the bandwidth required - you will need at least 4 discs - all working well together.
if you get either one wrong - it wont work well.

this is an article about the speeds of different large sata drives:

http://www.barefeats.com/hard68.html

www.storagereview.com
gives the basic stats for almost every drive

[GideonKiers]

Well, without spending money .. It's just that $30k for a raid system seems a bit of a waste. Spending the money smart, is what i would say. HDforindies is an interesting place yes, i read that too. It's the DYI thing. You don't need a million dollar recording studio to make a hit record. We're allmost there in filmmaking land. It's just the conversion that is a pain. (Same for doing dolby encoded 5.1 btw)

[samsc]

30k$ for a raid system?

have you looked at the prices of discs?

they are nowhere near that much.

even the basic xserve raid with 4 drives - enough to do HD - costs $6000

---

you want to do a homebrew scsi raid? - a case costs $300
4 drives around $1500 total
a controller card $400

---

you want to do sata raid?
4 drives - 1000$
case $2-300
card $1-300

[GideonKiers]

Yes well, i was overdoing it a bit, allthough it's easy to spend that amount on a raid.

Depending on the frame rate and resolution, you need write speeds of at least 120MB/s and as high as 180MB/s.
Why not just use Ultra320 SCSI arrays -- aren't they faster? They are historically faster, but are expensive and the drive capacity is one-third that of most contemporary SATA and PATA drives.

http://www.barefeats.com/hard46.html provides an interesting speedtest.

[samsc]

Yes well, i was overdoing it a bit, allthough it's easy to spend that amount on a raid.

i think it would be quite hard to spend anywhere near that much - as the top of the range fibre channel xserve raid is 13000$ - 14 discs - 7TB storage.
maybe you need 40 TB storage??

http://www.barefeats.com/hard46.html provides an interesting speedtest.

this pci-x adaptor is only $139.
the 4 drive case $500

[GideonKiers]

ok, the solution mentioned in the article below for pci-x is for a 4 or 8 disk raid system:

- SeriTek/2eVEN4 4-Bay External eSATA Enclosure Bundle with 4-Port Host Adapter - 630$
- 4 Raptors 74gb - 644 $
total ± 1300$
double that for read&write speeds around 400 MB/s and more storage, of course.

still hoping to find a solution that would provide a bit more hd space than the raptors ..