Raid 0 - How reliable is it really...?

DJPadre wrote on 6/1/2007, 12:22 AM

OK, well im going to start building a new machine with Raid arrays and all the other good stuff that makes vegas run nicely..

Now ive never ran a raid.. never needed it, but i have 8 drives here on this machine, and over teh years, this box has had 2 motherboard changes, 2 cpu changes, im still using my old Corsair 3200 400mhz 1gb CAS2 ram, and ive recently updated the GFX card to an nvidia AGP 6800GT

reason i have 8 drives is that each are abotu 120 to 250gb
4 drives each house at least 2 long form projects
1 drive is allocated to be audio sources, another is projects, another drive is for mastered renders and another is a spare jsut in case i need to transcode
8 all up

ok, so eventually THIS machine wil become my drafting and dvd processing box

the point i guess is to determine how reliable a RAID 0 really is.. i want to run at least 3 or 4x320gb Drives to capture and be the "reading" drive during editing, i then want the same thing to write to.
Is this possible?
Im not the best with building machines in this fashion as my own clients have no need for this kind of througput
We usually just stripe the2 drives through a raid card or what have u

I want the entire box to be self sustained so i dont want network drives and the like, im just looking for a good solution which wotn fry each time windoze has an issue with the MBR.
Ive lost about 4 drives in 5 years becuase of windows issues...

any thoughts or ideas, id be glad to hear them.Be it system or drive related... a dual quad core with 4gb ram would be nice.. lol

Comments

farss wrote on 6/1/2007, 1:32 AM

From my experience the mobo RAID controllers aren't to be trusted. Lost the RAID array several times and I gave up on it. The Highpoint controller in my big monsta is fine.

Bob.

douglas_clark wrote on 6/1/2007, 1:52 AM

I've had a 2x160 GB Sata150 Raid0 setup for 4 years as my main audio/video drive, without a single hiccup. (YMMV.) It used the onboard Intel Raid controller on my Intel D875PBX mobo. I recently bought a 500 GB Sata300 drive to replace the Raid0, and a Promise 4 port Sata300 TX4 adapter, now with 4 Sata300 and 2 Ata drives in my PC. All my renders run at 100% CPU usage, so disk access is not the limiting factor. The Raid0 did make a noticeable difference when copying and backing up huge files, however.

If you have a PCI bus system, or your Raid controller uses a PCI bus internally, keep in mind that the bus may become a limiting factor in how fast you can read stuff from your 4x Raid0 array. And having 2 such arrays (your "read" and "write" arrays) may never reach full throughput, because the bus bandwidth is insufficient.

PCI bus is 133 MB/s. The bandwidth on the newer PCIe bus is at least double that. PCIe x1 offers 250 MB/s in both directions, and PCIe x16 is at 4 GB/s. Couple that with a quad CPU on a new motherboard, and your proposed dual 4x Raid0 arrays might begin to make sense.

As for reliability... you still need to back it up, just like anything else you have on disk. If you ever want to move your Raid array to another machine...forget it. You would have to copy everything to a separate drive before rebuilding the array in another PC. (That is why I dropped my Raid0 array...I plan to build a new PC soon.)

Bill Ravens wrote on 6/1/2007, 5:04 AM

I've had a RAID 0 with Western Digital drives running for 5 years without a failure. I've had a single OS drive fail, but, never lost data on my RAID drives. Maybe my time is up.

richard-courtney wrote on 6/1/2007, 5:53 AM

Does your controller supprt raid0+1? This allows some redundancy where
a portion of each drive is used to back up the other drives.
If my memory serves me four 200G drives give you 800G using raid0 but
raid0+1 gives 600G but if one drive goes bad you replace it and rebuild.
The replaced drive is rebuilt from the copies in the other 3 drives. These drives can
be built on one machine and moved to another. (provided you don't mix them up)

I have a 3ware controller.

JJKizak wrote on 6/1/2007, 6:51 AM

I have three SATA 2-drive (Maxtor) raid setups in two computers running for about 2 years and they are solid. I plan to use a single SATA for a "C" drive later on.
JJK

blink3times wrote on 6/1/2007, 6:58 AM

I've done my best to stay away from RAID.... it's just something else to go wrong. Granted some operate with no problems at all.... but I have also heard of some pretty nasty disasters.

If speed is what you're looking for then IMO invest in good memory, mobo and a fast, top-of-the-line cpu.... it's time and money better spent. I just got myself into a quad core.... boy, is it fast!!

rmack350 wrote on 6/1/2007, 8:36 AM

Well, the whole point of a RAID 0 or 5 array is to get fast disc throughput to support lightly compressed media. a fair sign that throughput is a problem would be if you can't play at full frame rate even though your CPU is not taxed.

Several points can be made:
--First of all, the 10k RPM Raptor drives have similar performance to 2 7200 RPM discs in a RAID-0 array. If you want speed on a boot drive, this might be a more reliable choice.
--RAID 0 multiplies your chance of total drive failure by the number of drives in the array.
--RAID 0+1 gives you half the storage but creates a mirror of two RAID 0 arrays. So your data is recoverable. There's a little more CPU overhead involved.
--RAID 5 requires at least three discs and writes parity info to one disk. The total capacity is the total of your discs less one disc. Reliability is very high since the array will still limp along with a disc missing. Performance is almost as good as RAID 0 but there can be added CPU overhead. A good controller card that can take on the overhead but these are usually a little pricey they often require a faster slot than just plain PCI.
--for integrated RAID controllers, Intel's Matrix RAID on the ICH7R, 8R, 9R (or DH) southbridges get good reviews There's something over at Tom's right now regarding the new chipsets using the 9R southbridge.

I've also seen external array boxes for e-SATA, including one that had the controller built in and required just one e-SATA cable. I can't speak to performance but I'd think you could move this between machines.

Backups are really important with a RAID-0 array so you need to allow for that.

Rob Mack