Western Digital's Raptors in RAID-0: Are two drives better than one?
by Anand Lal Shimpi on July 1, 2004 12:00 PM EST- Posted in
- Storage
Parallelism has been a topic of interest within the PC technology industry ever since its inception. The basic principle of computing is to accomplish incredibly large and complicated tasks through the completion of smaller individual tasks, which in some cases, can be executed concurrently to maximize performance. We've seen examples of exploiting parallelism in computing with technologies such as multiprocessor systems, Hyper Threading and, of course, the long-missed Voodoo2 SLI.
The benefits of parallelism vary depending on the application. For example, the impact of dual processors or a Hyper Threading enabled CPU can be as little as 5% for a normal desktop user, but as much as 50% for a server system. Graphics rendering is virtually infinitely parallelizable, with a doubling in raw GPU power resulting in close to a doubling of performance. But what about hard drive performance? Are two drives better than one?
Of course, the technology that we are talking about is RAID, standing for Redundant Array of Independent (or Inexpensive) Disks. As the name implies, the technology was introduced for redundancy, but has morphed into a cheap way to add performance to your system. With the introduction of their 875P/865 chipsets, Intel brought the two simplest forms of RAID to desktop users for free: RAID 0 and RAID 1. With the majority of Intel's chipset shipments featuring RAID support, desktop users are beginning to experiment, now more than ever, with RAID as a method of increasing performance.
On paper, RAID can provide dramatic increases in performance. But as we've shown in our other hard drive reviews, the real world often differs greatly from the realm of synthetic disk benchmarks. So, what happens when you measure the real-world impact of RAID on today's fastest, most disk limited systems? Should we all start buying two hard drives instead of one? Or should RAID still be used for redundancy and not for performance when it comes to the average desktop user?
Let's find out...
Facebook
Twitter
RSS
127 Comments
View All Comments
Insomniac - Thursday, July 1, 2004 - link
I was wondering how RAID1 reads back data. I thought if it was smart, it would use both drives and improve performance. If that wasn't the case, I wondered if you could choose which drive it read from. That way, you could get a WD Raptor II and a low cost 80GB hard drive to pair up. You get the redundancy and speed of the Raptor for a lower cost. What about RAID5? (I know the ICH5/6 doesn't support it, but I thought there were some chipset m,akers that did. I would like to see what that brings to the mix. Given the choice right now, I'd take redundancy over performance. Maybe RAID 5 can give you both for less than 0+1.Pollock - Thursday, July 1, 2004 - link
I really wish some regular 7200 RPM drives had been used, considering someone who can afford a 74GB Raptor won't care about the costs of RAID anyway. =P Besides, to me it seems like Raptors already perform so well that it's hard to find any performance gain anyway. I was also under the impression that a lot of people with SATA drives in RAID 0 were actually getting much more noticeable performance gains; i.e. outperforming lone Raptors. Well, whatever.goku21 - Thursday, July 1, 2004 - link
I noticed that they came to the conclusion of only using 2 drives in a RAID setup, but in my expereince the more drives the supposed increase in performance. Perhaps they should revisit this with 4 Raptors in a RAID setup.kuk - Thursday, July 1, 2004 - link
Just one small thingy ... why is the manufaturer stated in the article summary "3Com/U.S. Robotics"?parrybj - Thursday, July 1, 2004 - link
While your overall disk bound throughput may be higher, seek times are sill only as fast as the slowest drive in the array. Since seek time is a more important desktop performance metric, I would think there would be very little benefit to doing this.Marlin1975 - Thursday, July 1, 2004 - link
Well the review was nice if you are thinking of running 2 raptors on a ICH5/6 SATA ports, but what about the other 99% of use that may use VIA, SiS, etc.. and/or other 7200 rpm hard drives?Matthew Daws - Thursday, July 1, 2004 - link
I'd be interested in seeing how using RAID0 with older drives, or one old drive and a newer drive, works out. If you're upgrading your motherboard, then given that RAID comes "for free", it could be a good way to save money by buying a second, smallish hard-drive, and using your old hard-drive with this new one in parallel...parrybj - Thursday, July 1, 2004 - link
Very good article. The results are not surprising. I have one comment about RAID1. While in theory it is simply a data redundancy mechanism, in practice there are performance benefits. Any good RAID1 algorithm will use read optimizations that will allow for parallellism during read requests. Thus, under the right conditions, most RAID1 arrays will achieve higher read IOPS than a single drive. Also, there may be a performance hit on writes due to the fact that writes will only be as fast as the slowest drive.djm2cmu - Thursday, July 1, 2004 - link
#4: Excellent introduction to all the common RAID levels here: http://www.acnc.com/04_01_00.htmlnofuse - Thursday, July 1, 2004 - link
This article doesn't seem to be up to the standards I've come to expect from Anandtech.It would be more fair to say "Intel's onboard RAID 0 solution offers no performance gain." I'd be interested to see results from other RAID controllers. You can't take one product and make a blanket comment like "RAID 0 is not worth it." That would be like me reviewing an NVIDIA Vanta graphics card and saying "3D acceleration is not worth it."