Since I love hardware debates, I thought I throw in my 2 cents worth. I also have a quarrel with a couple of the issues that are often raised, so I also want to get those off my chest.
You know RAID 0, the misnomer (Redundant Array of Inexpensive Disks) because it's not a "redundant array"Â at all, but two hard drives working together as one, with data being "striped"Â between the two drives. Because data is split between the two drives, it can theoretically be written or read at almost twice the speed of a single drive. A quick measurement of the average sequential read speed of my RAID 0 array shows this to be true, as seen in the HD Tach screenshot below.
My setup consists of two Seagate Barracuda 160GB SATA/300 drives in a RAID 0 array, giving a total of 320 GB of storage. In quick benchmark mode, HD Tach measures the average sequential read speed at 89.4 MB/s, with a massive burst speed of 356.8 MB/s (exceeding the theoretical maximum SATA/300 interface speed of 300 MB/s). Compare this to the library benchmark for a single Seagate Barracuda 160GB SATA drive of 47 MB/s.
This looks impressive, but as others have pointed out, in most real applications RAID 0 offers only small improvements in application performance (probably not even noticeable), as hard drive read/writes are not usually performance limiting factors. The benefits will be greater for applications that must read and write very large files, such as video editing.
So who would bother with RAID 0 on the desktop? Well, in short, hardware and performance enthusiasts like me. When I built my RAID array, I already knew from research that real application performance improvements would be negligible, but to a performance enthusiast, every bit counts (and RAID 0 makes a big different to synthetic performance benchmarks!). I couldn't stand the thought of that RAID controller on the motherboard sitting idle, when it could be pushing my benchmark scores a bit higher, and who knows, maybe loading those FS textures a bit quicker?
And now to clear up a couple of (non) issues that are often raised about RAID 0:
1. Why go to the expense of buying a second drive for a small performance gain?
There is no extra expense, in fact it's often to cheaper to use RAID 0. For example, if you want 500 GB of storage, you could either buy a 500GB Seagate SATA/300 drive for $320 (Today's price at Ascent Technology), or RAID 0 two 250 GB Seagate SATA/300 drives at $130 each, saving a total of $60!
2. You'll halve your overall drive life and lose all your data!
I love this one, it pops up all the time. I recently read an article on the respectable Anandtech site that talked of RAID 0 "halving of the mean time between failure rates on each drive"Â Eh? If a drive has a mean time before it fails of, say, 10 years, then putting it in a RAID 0 array does not change that fact.
It's a matter of keeping things in perspective, and being cautious of percentages (including doublings and halvings) on their own. I remember listening to a boring sales report at a company where I used to work. The sales manager proudly stated that sales of Super-Tab (the name of the product) had increased 100% since last year. The wit sitting beside me whispered "yeah, this year they sold 2 boxes"Â.
The thing to keep in mind is that, on average, hard drives are very reliable, that's why Seagate can give them a 5 year warrantee. If a drive has, for example, a MTBF of 10 years, then we might a number of drives to last longer than this, and some to last a shorter time. Let's say 0.5% fail within 1 year. If you have one drive in your system, there will be a 0.5% chance that it will fail within one year. If you put two in a RAID 0 array, then you have doubled your chance of a single drive failure within one year "“ but that's still only a 1% chance, pretty good odds (Note: in a RAID 0 array, if one drive fails, all the data is lost). Now I've made these numbers up, but the point is that 2 times a small chance of early failure, is still a small chance of early failure.
Of course the only person keenly interested in whether their drive will fail within a year must be making yearly data backups, which brings me to perhaps the best counter to the data loss argument: regardless of what type drive setup you have, if your data is important to you, you should be backing it up regularly to external storage. If you do this, you will be protected against any hard drive failure.
Any other issues with RAID 0?
I haven't yet set up a RAID array under Windows Vista, but setting up under XP does require an "F6" floppy disk with RAID drivers on it "“ and who uses floppies anymore? (I do know that Vista does not require floppy disks, finally we're free!). When I set up my array I had to go and buy a floppy drive just so that I could install Windows XP. I now have a brand new floppy drive to add to me discarded computer parts museum. It's one of those interesting examples of how fast computer technology moves forward. There are still plenty of computers out there with 3.5" drives installed. They use disks that store a whopping 1.44 MB, which you can still buy for $1 each. However, I can buy a much snaller 8GB Compact Flash card to plug into my multi-card reader (which occupies my 3.5" bay) for $180. That small piece of plastic holds the equivalent of 5,555 floppy disks. That's $5,555 dollars worth (although you might get a volume discount). And can you imagine how long it would take to read them. At about 2 minutes per disk, that's almost 8 days.
Anyway, getting back to RAID 0, the only other issue I've had was a problem with Adobe Creative Suite CS2 product activation. It was quickly resolved with a patch from Adobe.
Note also that with two drives, your system will be noisier.
So, what would I recommend?
Unless you're a real performance/hardware enthusiast, I wouldn't recommend you go to the trouble of pulling your computer apart and installing RAID. It's a huge job on an existing system as you have to reinstall windows (assuming Windows will be on the RAID drive). I know as I've done it. Also, this route will cost you money as you'll have to buy at least one extra drive (unless you already have two identical drives in your system), probably two matched drives.
The ideal time to think about RAID 0 is if you are building a new performance box from scratch. Just remember, if you're installing XP, you'll need a floppy drive. Building a new box also means you'll have the latest technologies "“ the latest RAID controller, and a SATA/300 interface.
Out of interest, my current plan for when I move to Vista later this year is to, initially at least, move back to a single high capacity drive. One of the new high performance perpendicular Hitachi drives (if I can afford it). Currently only the 1TB model has been released, but smaller capacities are expected. I want to do this partly to minimize the chances of running into problems under Vista, partly because I would like more storage capacity, and because I'd like to reduce overall system noise (I also plan to add the 8800GTX into my water cooling loop to rid myself of that fan).
That's all - thanks for reading.
