topic Re: detailed specifications for SATA and SCSI disks in Disk

detailed specifications for SATA and SCSI disks

Andreas Kamer — Wed, 04 May 2005 09:35:23 GMT

Hi all

We are planning to implement SATA-based server solutions for our very small customers.
I was looking for some detailed specs (MTBF, duty cycle, reliability, etc.) to compare HP's SATA and SCSI disks. Unfortunately I didn't find any.

Are there any detailed specification sheets for SATA and SCSI disks available or does anyone of you have experienced significant differences between HP's SATA and SCSI disks?

Thanks a lot for your help.

Best regards,
Andreas

Re: detailed specifications for SATA and SCSI disks

Oleg Koroz — Wed, 04 May 2005 14:50:12 GMT

http://h18004.www1.hp.com/products/servers/proliantstorage/serial/sata/index.html

http://h18004.www1.hp.com/products/servers/proliantstorage/drives-enclosures/docs/index.html

Re: detailed specifications for SATA and SCSI disks

e4services — Thu, 05 May 2005 09:21:45 GMT

Take a look at Seagate
http://www.seagate.com/products/discfamily/esgintfcs/index.html
They are the first level and can give you the most information for your decision. Of course you will need some sort of Thesaurus, "SATA enterprise disc drives are purpose-built for nearline use in direct-attach tiered storage environments"
God Love Marketeers.

Re: detailed specifications for SATA and SCSI disks

Alzhy — Thu, 05 May 2005 14:07:48 GMT

It used to be that SCSI/FC drives lords it over its ATA/IDE cousins in terms of performance, reliability and MTBF's. Not anymore - there are now available a new generation of SATA drives that are Enterprise Rated -- see Western Digital's Raptor series .. they are rated for up to 1,000,000 hours MTBF.. basically approaching the MTBF of SCSI drives.

See http://www.wdc.com/en/products/Products.asp?DriveID=40

I am not sure though if HP's SATA offerings (some of which are hot plug btw) are based on Western Digital drives.

Re: detailed specifications for SATA and SCSI disks

Larry Dana — Thu, 05 May 2005 16:31:41 GMT

But,

The Western Digital Raptor has an MTBF of 1.2 Million Hours, where the Seagate Cheetah has an MTBF of 1.4 Million hours, all the other specs are about the same until you get to the Data Transfer Rate, a whopping 320 MBps! more than twice the rate of those "oh so cool" SATA disks.

And it is only about $70 more.

Let's see; 200,000 more hours (estimated), twice the data transfer rate, hmmmm... I think I'll spend the extra $70.

Re: detailed specifications for SATA and SCSI disks

Cass Witkowski — Mon, 08 Aug 2005 12:23:15 GMT

I was at a recent boot camp and was told that the MTBF for SATA drives was around 600,000 hours and 1,200,000 for SCSI drives. It looks like newer drives have improved that.

The main thing they pointed out was that the MTBF for SATA drives is only valid if your duty cycle on the drives was 20% or less. If you use the drives more than that the failure rate goes up. SCSI drives are designed for 100% duty cycle.

Regards

Cass

Re: detailed specifications for SATA and SCSI disks

generic_1 — Mon, 08 Aug 2005 13:39:35 GMT

Check out storagereview.com They have some nice articles on disk performance. As far as disk life I think those specs are crap. Do you really think your data is going to last 60 years or more LOL. Find a product that meets your throughput and redundancy requirements, and do a google search to find complaints or problems. The Ones with the most complaints and failures are usually the ones that will cause you the most grief if your dumb enough to buy one cause you got a good deal scsi or sata. You are going to have to look more at the storage solution than a disk model in most caes though, because they may use different disks in their products, due to cost, problems, and who had the best salesperson, on a given day. They way you layout your data on the product you use will make a very large impact. Remember to keep firmware up to data. This can really bite you in the storage arena.

Re: detailed specifications for SATA and SCSI disks

generic_1 — Mon, 08 Aug 2005 13:43:10 GMT

The raptors are nice, but I have not seen any major vendor offering them as a specific option. I would be interested to know who does for sata reasons. Just remember you cant just go stick em in your storage solution unless they are supported. Sometimes they modify disk firmware for their product.

Re: detailed specifications for SATA and SCSI disks

Cass Witkowski — Mon, 08 Aug 2005 13:43:21 GMT

Do not confuse MTBF to life of a drive. MTBF is just a failure rate while the drive is in it's normal service life. Typically 5 years. After the drive has exceeded its service life then the failure rate increases