Raid - is it worth it?

[aidanjt]

Assuming you have two identical drives (different manaufactur batch!) and each drive has a MTBF of 500,000 hours. Assuming too that the initial failures (the start of the 'bath tub' curve) have been filtered out by the mfr burn-in process, then with one drive, you are likely to get a failure some time in the next 500,000 hours. Add two drives to an array (RAID 0) and the chances are you will have two failures in the next 500,000 hours, or one failure in 250,000 hours. In other words you halved the MTBF and doubled the risk of losing all your data. Now it might be the reduction of risk from a small number to a another small number - but it is still a factor that you need to consider. Certainly for RAID 0 I would want to use enterprise grade drives to ensure the MTBF is as high as possible.

Yes, but lets stay in reality here, 99.9% of people who use identical drive models in RAID will order them all in the same batch. At the end of the day, there's no substitute for a good backup policy, because frankly you have no idea when your disks will fail no matter how much you attempt to rationalise it, all these rules of thumbs and metrics are completely wrong and (worse) misleading.

[Sema4]

Raid isn't for everyone, it really depends what you use your computer for... take in to account the games you play and the resolution of your screen, it's all relative as to whether or not you will see a significant performance boost with RAID.

In my case, the most practical application of raid that I have found, is a pair iRAM 4Gb cards in RAID 0 for windows and VM, a pair of 150Gb raptors in RAID 0 for active storage and a selection of single drives for archive storage.

The 8Gb iRAM RAID 0 reduces rotational latency to zero and makes an unbelievable difference to windows and virtual memory, while the Raptor RAID 0 decreases load times for all the programs that are installed on it.

The single drives are used to store valuable files, and spend most of their life turned off. I turn one on if I need something off it, then it goes off again. My iRAM array and my 'documents and settings' folder on my raptors, both get synchronised to backup copies located on a single drive, once a week, or sooner if I have been doing something important.

Everything that gets 'installed' (ie games, programs, utils, etc) goes on the Raptor RAID, and if a drive falls over, all I have lost is my install of Flight Sim X or what ever happens to be installed at the time... not really a big deal when it can be easily installed all over again....

For me, the performance benefit from RAID is well worth it, particularly running flight sim running at max resolution on a pair of 24" Dell flat panels, you can really see the performance increase over a single drive system both in load times and smoothness of game play..... If you don't think it's worth it, then I guess your not as much of a performance junkie as me

[master811]

Enter The Matrix: Slice out and get the best part from your hard drives is well worth a look. what many raptor fans forget to mention is the noise, i know 2 or 3 people who have got rid of raptors because of that. Must admit i'm a fan of intel's raid implementation, far better imo than the nvidia i'd dabbled with on nforce 4.

I've been looking at this for a while and am definitely intending on using a matrix raid in my next system.

I like it especially as it means you can save space in the case with just 2 larger drives (and not have to use all of them for Raid 0)

[peterb]

Yes, but lets stay in reality here, 99.9% of people who use identical drive models in RAID will order them all in the same batch. At the end of the day, there's no substitute for a good backup policy, because frankly you have no idea when your disks will fail no matter how much you attempt to rationalise it, all these rules of thumbs and metrics are completely wrong and (worse) misleading.

I agree - there is no substitute for a good backup policy (which I think I mentioned in an earlier thread) but RAID 0 does reduce the reliability of the data storage system. The significance/importance of that is a matter of judgement for thye user.