Originally posted by: LED
Hmmm not to knock your post but if I had a choice between 1 Faster HD with the same space as a slower 1 X2 @ a lesser price than i would go that route as well
Yes Raid0 is not twice as fast as IDE/SATA x2 but faster or equal non the less...prefer RAID5 myself
Nope, not neccesarily. Someone needs to brush up their knowledge of IO.
RAID0 means two things for performance:
1) Twice the bandwidth. Obviously, you can read or write from both drives simultanously, so you only need to do half as much on each drive.
2) Higher latency: Just as obvious. Instead of locating data on one disk, you need to locate it on both. Seek times on harddisks is already a huge bottleneck. Once the data is located, you can read/write in the order of 30-50 mb/s. Thats amazingly fast compared to how much you spent on seek time already. (Yeah, compared to everything else, it's slooow, I know that)
So, now you need to spend more time locating data, but the transfer goes faster. That is *no matter* which controller you use. Yes, a faster controller might mean less performance loss on the former, and more performance increase on the latter, but it doesnt' change the above.
So, now it should be really obvious. Everything that requires big sequential reads or writes (loading big (nonfragmented) files, writing database log files, or possibly loading Windows, can benefit from RAID.
You spend a bit longer locating the place to start reading/writing, but once there, you can double the transfer speed.
But normal desktop use isn't exactly characterized by sequential I/O's. Rather, that's a matter of thousands of small (and usually fragmented) files, which means more time spent searching the disk, which is slower with RAID, and less time spent on transfers (where RAID could be an advantage).
Before you mindlessly defend RAID, read up on on IO and disk performance in general. Yep, most people say it's faster, but that's because they don't look beyond the bandwidth improvements.
There's a reason why even people working with database tuning use RAID for data reduncancy only, and rarely for performance.