View Full Version : RAID5 or RAID3 ?

07-29-2003, 12:47 PM
Which is the best option for VT3 and WinXP?

I need SCSI redundant video storage, which SCSI board i must buy to have RAID5or3 features?

My MOBO option is SuperMicro X5DAL-G (MBD-X5DAL-G-O)

Eric Pratt
07-29-2003, 01:20 PM
I've got a RAID 5 with an Escalade, not really outstanding speed but large, cheap, and redundant. I have a smaller 6 drive SCSI stripe that I do my active work on and then move it back to the Escalade when done.

07-30-2003, 09:58 AM
see http://forums.newtek.com/discus/

Under VideoToaster/Hardware Wars there are a couple of threads you might want to read:

"Raid 3 or 5"

"Caen Engineering RAIDs"

(note: I don't know whether "Symation" still exists, the owner recently passed away. CAEN is still around, though).

07-31-2003, 09:03 AM
old forum is very usefull! GREAT! :D

note: Im collecting information about Mylex AcceleRAID 170

Originally posted by Sledgehammer
Raid 3 is better. To avoid getting too techinical, the parity information on RAID 3 is stored on a single drive, whereas RAID 5 stores the information spread out over the entire array.

So, let us say that a drive dies. On a R3 system, like the excellent Medea drives, you would lose the parity storing capablity until the drive is replaced. But, since the parity information is stored on a separate drive, it can take the place of the dead drive and keep the speed up to R0 numbers. This allows you to keep working and meet the deadline, and when the project is done, get the drive swapped.

If a R5 array loses a drive, then the array slows down to the speed of just one solo drive until the array is rebuilt. Not too bad for servers, but it stinks for multi-stream uncompressed NLE's.

In both cases, the original data is secure, and any further writes to the drive will be secured when the array is rebuilt.

We had the chance to use a Medea at a trade show, the bad boy 10/960. This is a dual channel array, with almost a terrabyte of storage. We hooked it up dual channel to our VT2, and got some amazing numbers off of it: 179mb in Auto-config, drive test showed 187. Amazing when you realize that it is redundant, and downtime can be all but eliminated by having an extra drive to swap out.

07-31-2003, 10:46 AM
The CAEN RAID set up is superior in that you have a hot swappable option.

We lost a drive in one of the arrays recently, and it rebuilt itself in surprisingly quick fashion.

Anyone with a gun to their head to meet deadlines would be crazy not to go RAID Level 3.

If this is too expensive, then I recommend a brute-force IDE backup scheme after digitizing source files.

08-04-2003, 12:03 PM
I'm looking into getting more storage as we speak, (type).
What kind of costs are we looking at for the "10/960" and the "CAEN".
I'm looking at getting about a terabyte of external storage to supplement my internal raid 0.
I really like the redundancy option since I'm so darned paranoid about losing stuff at the worst possible time!

Also, my dealer is really getting good results with IDE's. I have need for real time speed, so is anyone getting close to equal results using IDE's over SCSI?

Thanks in advance.

08-04-2003, 12:06 PM
The CAEN RAIDS that we have consist of 5 drives in each of two raid sets, and one hot-swappable spare. 6 drives total, expandable to 8 drives per rack-mounted box.

The unit comes with the software necessary to set up the internal hardware controller(s) any way you want: Raid 0, 1, 3 or 5. This can be done either from the front panel of the unit(s) or from a computer, hooked up as a terminal to the Box. They were striped with this software as (2)individual RAID Level 3 arrays.

In our case, Win 2K "sees" each box as a single 450 GB drive, with each hooked up to the two U160 controllers on the P4DC6+ MOB, and we have them striped together as a single RAID Level 0 device in Win 2K.

It was around $14K for the two, so figure around $7K for one of them. BTW, I believe there is a performance gain having two of these bad boys....

Last test using autoconfig showed 157MB/s throughput.

08-12-2009, 08:58 PM
which is the best performance to build a raid3 or raid5 diskarray to play HDTV ?


08-14-2009, 08:52 AM
I will suggest 3ware raid card with SATA-II drives. I have installed them to several VT customers and they are happy with it. Choose at least 8 ports card, best with 12 ports or more.
With 12 SATA-II drives, the sustained RAID-5 write can be as fast as 280+MB/sec, and Raid5 Read above 400+ MB/sec.

For old M/B with PCI-X slot, choose 9550SXU-12 and up
For newer M/B with PCI-E, Choose 9650SE-12ML and up.

The 3ware said 9550SX can have throughput as 480MB/s Raid5 read and 333MB/s write.