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RAID3 controller card

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February 19, 2007 4:36:21 AM

Which would you suggest? It must fit in a pci x16 slot or regular pci slot, have at least 8 sataII inputs, and be under $750.

Thanks

More about : raid3 controller card

February 19, 2007 5:31:10 AM

RAID 3? It exists, but I don't know anyone who has ever used it.
$750? You can get 4 large drives and a controller for that money. check newegg.com
try getting one using a PCIe x1 slot. 1X is still much faster than a regular PCI slot and a lot smaller.
Go with RAID 5 unless you have some very special reason.
http://www.newegg.com/Product/ProductList.asp?Category=...
February 19, 2007 11:14:27 AM

raid 1- 10 and maybe more exists but i know for a fact those exist.

are you sure you actually need raid 3?
Related resources
February 19, 2007 12:20:37 PM

From what I have read, RAID 3 offers some of the best performance with redundancy. It is usually recommended for dealing with video and other large files where the insecurity of RAID 0 is unacceptable. Newegg only carries Areca controlers which support RAID 3. They are all pci-e x8 ranging from $500-1000.

Are there any other brands to consider? Or, Is there another RAID option that will give me the transfer rates necessary to capture HD video with some redundancy?

Thanks
February 19, 2007 12:35:35 PM

yes, raid 10 , raid 5 , raid 1 ( i think ). but i am sure raid 5 and 10 would be better. spending 500 - 1000 for something like that better have a lifetime warranty and comes with 24 hour support and a free hug :p 
February 19, 2007 2:07:09 PM

An excellent Raid 3 overview. http://www.acnc.com/04_01_03.html

A quick search for a raid 3 controller landed me only one result.
http://www.newegg.com/Product/Product.asp?Item=N82E16816110002
Not exactly a great brand name either.

EDIT:
Found another more reputable controller.
http://www.newegg.com/Product/Product.asp?Item=N82E16816131003

Looks like Areca has a strong backing for Raid3. Most of their high end SATAII controllers have Raid3 support.
http://www.newegg.com/Product/ProductList.asp?Brand=10526&N=2010150410+50010526&Submit=ENE&Manufactory=10526&SubCategory=410
Nearly every Areca card on this list supports Raid3
February 19, 2007 2:48:22 PM

No one would ever user raid3 when 5 was availiable. with a fixed parity drive your write speed is always the speed of a single drive
February 19, 2007 2:55:18 PM

that is incorrect. your parity is calculated on the write and then written to the parity drive on the next read. Its a delayed reaction.

PC Perspective Review
Beginning of Review
Benchmarks
You will notice that Raid 5 has a slight Read advantage, but that Raid3 makes up for that with a much improved Write performance.
February 19, 2007 2:56:47 PM

You do not want a RAID 3 setup. It will not capture HD video anywhere near as fast as you need.

RAID 3 is similar to RAID 5 in that multiple drives are used with parity information on the drives to provide redundancy. In RAID 3, all the parity information is stored on one drive. Since the parity information must be written along with all the data, the parity drive is a bottleneck, slowing transaction rates for the entire array to that of a single drive. In addition, to achieve maximum possible performance in the RAID 3 setup, the hard drives must be spindle-synced, which most cards no longer support.

RAID 5 has distributed parity, where the parity blocks are distributed over all the drives. In this setup, the theoretical write speed would be (n-1) * (write speed of 1 drive), where n is the number of drives. This would be further limited by the speed at which the parity data can be calculated.

The AMCC 3Ware 9650SE-8L is an 8-drive SATA-300 RAID card incorporating RAID 5 capability (as well as RAID 6). The interface on the card is PCIe x4, which can plug into a PCIe x4, x8, or x16 slot. (Be aware that some motherboards won't accept anything other than a video card in their PCIe x16 slot, so check motherboard compatiblity before you try that). The manufacturer claims this card can sustain 700MB/sec reads and 600MB/sec writes in RAID 6. Should be faster in RAID 5 provided the drives can keep up with it.

Uncompressed 1920 x 1080 HD (RGB) @ 30fps is 186MB/sec. Thus this card should handle this data stream no problem. (By the way, that's 672GB per hour of captured footage ... with 8x 750GB Seagate Barracudas that only gives you space to capture for a little less than 8 hours before you fill up the 5.25 TB).

As far as what you read about RAID 3 being higher performance than RAID 5, you have to remember that many of the RAID descriptions and write-ups on the Internet were written a long time ago, when controller computational power was tiny. At that time, anything physically setup in in the array that simplified the design and reduced the firmware's job increased speed. RAID 3, with a single parity drive, synced spindles, and XOR in dedicated silicon reduced the firmware to simple block transfer.

This is no longer the case today. Today's RAID processors and PCIe interfaces can out-calculate any previous generation of RAID card, making simplifications in the array design unnecessary to achieve high performance. No one even contemplated RAID 6 until just a few years ago because the computational cost was prohibitive. Today, many manufacturers are making RAID 6 controllers.
February 19, 2007 9:05:09 PM

Would the 12-drive 3ware raid card with 9 750gb seagate hdds provide a good starting place with some room to grow? Since I will probably have 5-10hrs of hd content when I come back from vacations, I figured this would be a good mid point. Is it easy to add a drive later in a RAID5 array?

Thanks for the information
February 19, 2007 11:41:38 PM

so which raid is actually good when having a lot of videos and music on your hdd's? raid 5 or raid 10?

also

when using raid 5 is your write performance very slow when transcoding a movie ? is it a noticable difference when using raid 5 as compared to raid 10?

just wondering because i have raid 0,1,5,10 on my p5b duluxe mobo.
February 20, 2007 12:53:28 AM

Quote:
Would the 12-drive 3ware raid card with 9 750gb seagate hdds provide a good starting place with some room to grow? Since I will probably have 5-10hrs of hd content when I come back from vacations, I figured this would be a good mid point. Is it easy to add a drive later in a RAID5 array?


Either the 8-port or the 12-port 3Ware card will function at about the same speed, it's just the number of drives that each supports. You can't get the stated read/write speeds until you have at least 8 drives in the array.

My stated capture hours assumes you're capturing uncompressed HD in RGB format (this would be the most space-consuming format you could get). This is not necessarily what you're going to be capturing. I don't know what your HD source is, your editing system, etc. A lightly-compressed HD stream (used in professional equipment like HDCAM or HDCAM SR) can write at up to 110MB/sec (SR x2 version). Mid-range versions of HD like DVCPRO HD are only 13 MB/sec. Consumer versions like HDV are the same as DV (3.2 MB/sec).

When you first posted, I assumed you were building/using professional equipment and needed the data rates offered by the 3Ware card. If you're not, the 3Ware card and 8 drives is probably overkill.
February 20, 2007 2:27:20 AM

I havent looked at a cost analysis in a few months so i might be a little off but 8-12 sata drives in a raid5 would probably require either a massize server or an external storage case. At any point it seems like overkill and massively expensive.

Just a thought here, how about 4-5 SAS drives, that will get you all the bandwidth you need. Then you can use inexpensive e-sata drives or firewire drives to expand as needed.

Do you always have a massive amount of data going or is this mostly old projects that are just sitting around for storage purposes?
February 20, 2007 7:45:35 AM

Quote:
I havent looked at a cost analysis in a few months so i might be a little off but 8-12 sata drives in a raid5 would probably require either a massize server or an external storage case. At any point it seems like overkill and massively expensive.


Actually case can be done LIAN LI PC-201B with 7 external slots so 1 for the CD/DVD and 6 for the RAID cage $299

http://www.newegg.com/Product/Product.asp?Item=N82E1681...

SuperMicro SATA RAID Cages 5 drives per 3 5.25 slots. $135 each

http://www.newegg.com/Product/Product.asp?Item=N82E1681...

So two of those puppies will handle 10 drives

So then you have to throw in a 1KW supply and the matter of the 8-10 drives and controller, Motherboard, CPU, RAM, running the advert to sell the second auto and you are good to go. :) 
February 20, 2007 9:46:56 AM

the camcorder I plan to use is the [/url]JVC GZ-HD7
It has a capture rate of 30mb/s in mpeg2 format.

I do not really know what this means to me, so any help would be greatly appreciated.

Thanks
February 20, 2007 12:23:14 PM

Quote:
the camcorder I plan to use is the JVC GZ-HD7
It has a capture rate of 30mb/s in mpeg2 format.

I do not really know what this means to me, so any help would be greatly appreciated.

Thanks
[/url]

answer:

1. thats 30 MB a second which is 1,8 gigs a minute 108 gigs an hour.

if my calculations are correct...
February 21, 2007 12:15:46 AM

That's a consumer camcorder, recording in JVC's slightly modified version of HDV. The maximum data rate of the HD stream is 30 Mb/sec (megabit, not megabyte).

This translates to the standard DV data rate of 13.5 GB/hour.

The 3Ware card and any RAID setup is absolutely massive overkill for this application. You don't need any of that. A single standard 500GB SATA hard drive will let you store 37 hours of footage, and exceeds the needed data rate by a factor of 20.

Not to mention that the camera is hard drive-based, and you "capture" the footage to the computer via USB 2.0. The maximum capture rate over USB 2.0 will be about 25 MB/sec anyway, which any hard drive can easily keep up with.
February 21, 2007 12:25:59 AM

Friggin A!!!

And here we are thinking this is a major setup of some kind.

Feel like a noob for not asking for the first question you should always ask.
WTF are you using this for?

:?
February 21, 2007 1:27:18 AM

Quote:
Not to mention that the camera is hard drive-based, and you "capture" the footage to the computer via USB 2.0. The maximum capture rate over USB 2.0 will be about 25 MB/sec anyway, which any hard drive can easily keep up with.


Good catch in your post but I am confused by the part quoted above. Is it the cameras disk that is too slow? Unless I am just tired, I recall USB 2.0 as 480Mb/sec. Does the converted MB stated really reflect 50 percent overhead?
February 21, 2007 2:37:32 AM

There's multiple factors.

USB 2.0 is 480Mb/sec (60MB/sec) raw data rate, but due to USB's relatively high overhead, devices rarely even come close to this. The fastest external hard drive I've seen on USB 2.0 ran at about 30-35MB/sec. The same HD on 1394 ran at about 40 MB/sec.

I didn't delve into the camera's specs, but I'm sure for power saving purposes that the hard drive that's internal to the camera is a 2.5" drive, probably 5400 RPM. It's maximum data rate is likely to be in the 35-40 MB/sec range anyway, slowing as the head moves to the inner tracks.

Nevertheless, having a hard drive-based camera is very convenient, as capturing from tape is a tedious operation. The capture in this case is nothing more than a file copy from the camera to the computer. And at 30 MB/sec, that will enable you to get 1 hour of footage copied from the camera to the computer in 7-8 minutes, not bad at all.
February 21, 2007 9:36:09 AM

Just out of curiosity, would a tape camera take up more space when capturing to my pc?

Thanks
February 21, 2007 3:51:58 PM

Nope. The data space that the footage takes up is dependent on the codec used to compress the video, not the storage medium.

The DV, HDV, and JVC's modified HDV codecs all use approximately the same space and same bitrate - all are about 25 Mb/sec, or 13.5 GB/hr.

This space is used regardless of whether the footage is stored on hard disk or on tape. The hard disk in the camera makes the capture more conventient, however, as the file copy can go much faster than the filming. Capturing from tape must be done in real time (1 hour of footage takes 1 hour to capture).
February 22, 2007 1:32:29 AM

Quote:
so which raid is actually good when having a lot of videos and music on your hdd's? raid 5 or raid 10?

also

when using raid 5 is your write performance very slow when transcoding a movie ? is it a noticable difference when using raid 5 as compared to raid 10?

just wondering because i have raid 0,1,5,10 on my p5b duluxe mobo.


The only time you need to worry about using RAID to increase HD performance is when something is processing data faster than a single hard drive can handle.

Multimedia playback and trans-coding typically involve transfer rates that are a only a fraction of what even the cheapest hard drive can handle.

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That isn't to say that there aren't some uses that 100% require RAID, just not the ones you happened to mention.
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For motherboard RAID I stick with RAID 1, then test it to make sure that the drives are 100% readable by non-raid controllers.

That way my data is safe even if the motherboard dies and the only replacement is a newer revision with an incompatible controller (it happens).

--
!