How Fast/Reliable is RAID 5 for video editing?
 

How Fast/Reliable is RAID 5 for a video editing work station?

thanks!

It depends on:
A- on the drives you use.
B- on which RAID controller you use. There is a big difference between them all in terms of performance and CPU utilization.
C- Reliability depends on cooling, the hard drives, and stable power.

RAID 5 is typically very fast on reading data, and slow on writes. One hard drive can fail without loss of data. It may take a few to several hours to rebuild the RAID if one drive has failed, and the RAID will be slow in its degraded state.

Software-based RAID 5 would probably be slower than no RAID. Some RAID controllers don't have a hardware processor to handle the RAID calculations and may be just as slow? (Not sure.)

2- What format(s) are you editing?

The drives are 7200rpm 8meg cache Maxtor Calypso's--SATA150

Dual Xeon 3.2 mhz

Adaptec raid controller

Editing HDV

I guess the advantage of RAID5 would be that it protects you against hard drive failure.
You will lose a little capacity because one drive will be used for parity/error checking/error correction.

Speed-wise you should be fine as long as all the drives are the exact same model + capacity (and ideally firmware too). With the RAID controller, you should be fine as long as it contains a hardware processor on board- you may have to research your exact model.


One way to know things for sure is to run benchmarks. Sustained transfer rates shouldn't make a difference because you'd be comparing overkill to more overkill (HDV shouldn't need fast drives). CPU utilization would make a difference.

Brent,

after having just switched to a RAID-5 array after losing my spanned volume, i've noticed no differences on the speed/performance end.

I went out and got a Promise SX4060 card, it has a built in hardware controller and a ram slot - it comes with 64Mb, but you can place up to 256 SDRam in the card.

got it from newegg.com, and it works great :-)
~Mike

The Promise RAID controller might be one of those fake RAID cards? It doesn't actually have a CPU on it, so CPU utilization is higher.

According to the Promise SX4060 manual, it has "a Hardware XOR accelerator, which offloads the parity calculation workload from the main CPU and transfers it to the controller card, boosting the performance of the entire system.

I have four 250 gig hard-drives....should I do a RAID 5?

or just say Screw It and just install them each as separate hard-drives... then just do manial backups of data from one drive to another...??

Christopher:
It might just be the older/cheaper/other Promise models then. I'm kind of sure some of their other cards are fake RAID and offload calculations onto the CPU.

Brent:
Manually backing things up would probably be an inferior solution. It would take more hard drives or something like that.

If you can accept losing 250gb then I'd probably go for it. You would be fine if one hard drive fails. It doesn't protect against user error (AKA brainfarts), but I don't see how a manual backup solution would do that.

I have built the RAID 5 ... but now my problem is when capturing...

The video capture (vegas5) is stopping because of dropped frames...

I've scanned and de-fragged the drive...


ANY IDEAS?

Help!

1- The only thing that's changed is that you put the 4 drives into a RAID 5 set?
Presumably that's where your problem is coming from.

2- What is the exact model of your RAID controller?
Maybe doing a google search may find other people with problems with that card.

3- Are all your hard drives exactly the same? RAID performance will suffer a lot if they are not.
Sometimes drives will have different firmware versions (i.e. you bought them at different points in time). That will also subtly change the drive... not sure if that has ever caused a problem though.

The raid controller is an Adaptec SCSI RAID 2200S Dual Channel

The drives are all four Maxtor Calypso's

This is a 6500$ Dell system

HELP!

4X250GB drives (RAID 5, lose a drive to parity) should be about 697GB when formatted?? Not 650GB. Maybe a drive mismatch??

2- "Adaptec SCSI RAID 2200S Dual Channel" is a RAID controller for SCSI devices. Your hard drives are SATA.

3- How did you configure your RAID? (i.e. through the RAID BIOS)

4- If you need to get work done, I'd just abandon the RAID for now.