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Serial ATA vs. SCSI - Will it Compete?
fazzumar asks: "I've been checking out serial ATA (SATA) and it seems like it's got a lot of potential. The first generation spec was finalized August 2001 and members of the SATA group anticipate a 12-18 month acceptance period. They've planned for a cut-over phase and adapters that allow connecting SATA devices to ATA adapters and vice versa. The cables alone are a worthwhile advantage (4 pins, up to 1 meter in length), and the 150MB/sec bandwidth is a (minor) improvement over current ATA drives & adapters. Infoworld has a story on SATA that provides a few tidbits of information. What I really want to know is, will manufacturers of the new host adapters be able to integrate many of the advantages that SCSI provides or will the cost of adding these features push the retail cost too high for the anticipated market?" I just picked up a new WD Hard drive just yesterday for the planned MP3 jukebox I hope to be building near the end of the summer. I really wanted to go SCSI, but couldn't. While the poster claims a near ~7x in price difference, I saw about a ~5x difference in my local store. Is SCSI in danger of falling behind IDE drives (especially serial IDE drives) in popularity?
"I love SCSI, and I can bring myself to accept the additional cost of the controller, but with IDE hard drive prices dropping, I frequently wonder if SCSI drive prices are artificially inflated. Just a few years ago, SCSI drives were ~10-20% more than IDE and now they're ~7X more than an IDE drive. (Seagate 10k RPM SCSI - ~18 gig for ~175. Western Digital 7200 RPM IDE - ~120 gig for ~175) If the option comes out to get SCSI performance from an IDE drive I'm going to take it."
I frequently wonder if SCSI drive prices are artificially inflated.
... but generally speaking, they're the same thing. There are certainly not enough differences to justify the price. Is there some magic spell they cast on SCSI drives that quadruples the price? SCSI's "enterprise capabilities" make using SCSI on the desktop really expensive, so they continue to gouge us.
:(
Hell yes - There's no way they aren't. I'm sick of this price barrier myself.
Look at a SCSI drive and an IDE drive. Sure, there are some differences, MTBF, blah blah
What do we get in return, Technology that Should Not Exist(tm) - Things like IDE RAID.
Sucks being a SCSI zealot.
If the option comes out to get SCSI performance from an IDE drive I'm going to take it."
Review of the Western Digital 1200JB (The 8MB Cache Special Edition.)
With desktop performance and capacity vastly superior to the competition as well as a surprisingly low operating temperature, the Caviar WD1200JB reaffirms Western Digital's preeminence in the IDE desktop performance segment. In fact, for desktop usage, the JB bests all 10k RPM drives save only Maxtor's Atlas 10k III.
Once again we're obligated to point out an interesting fact. The hardware enthusiast market, comprising a significant portion of StorageReview.com's readership, has always pledged it would respond enthusiastically to the world's first 10,000 RPM drive. These folks want the performance of a 10k RPM SCSI drive without the SCSI premium. The WD1200JB, like the WD1000BB-SE, delivers the desktop performance of a good 10k RPM drive according to tests constructed from real-world, high-level applications. If you want SCSI's performance without its price or capacity limits, the WD1200JB is the drive for you.
The major difference is Queuing and Parallel Processing. Even today's IDE RAID controllers can't get more than one instruction down the pipe at the same time, and queuing is non-existent. Recently I have seen IDE cards that support extra RAM, but specs on the boxes don't read like they support queues. SATA will introduce the concept of a queue, and that will speed I/O greatly, but the biggest speed barrier is the speed at which the instructions are sent to the disk.
I run a small video editing shop. Real time video editing taxes disk I/O on PC's more than anything else I know of. I HAVE to run SCSI, and still, even with SCSI, I have to wait. Most of the time I am waiting on the I/O.
That being said, after reading the SATA standards, I will feel safe replacing more than half of my high-speed I/O channels with it. I am willing to have it manage everything except the most extensive reads and writes. I will soon be dedicating a portion of my web site to the explanation of SCSI vs. SATA. Bookmark it now.
tagged queueing has been in ide drives for many, many years now
Sometimes, you have to love ebay. I still need a few drives, for which the smaller ones go about $1 per gig. 256 drives before I run out of room. The only thing that will hurt me price wise, is a decent rackmount drive case. Software raid, at very nearly the max theoretical throughput.
SCSI was nice, but it is dead. IDE is alive, but it sucks. Fibre channel is seen as an enterprise-only tech, and they no longer have use for the small stuff on their SANs. I'm not so proud that I won't humbly accept their table scraps.
Oh, and before anyone else mentions it... I don't have to use expensive fiber. That's only for ridiculously long cable runs. 20 meters max for stp cat5. More than enough.