Serial ATA

[Hardware Secrets Team]

There has been a new article posted.

Title: Serial ATA
URL: http://www.hardwaresecrets.com/article.php?cat=&id=27

Here's a snippet:
Serial ATA - or simply SATA - is the new hard disk standard that will finally reaching the market. Although the standard was set up in 2000, makers of hard disks and motherboards have taken some time to unveil ...

Comments on this article are welcome.

[Merman]

Quote from page 1:

Native Command Queuing (NCQ) increases the hard disk drive performance by reordering the commands send by the computer. Read our tutorial NCQ (Native Command Queuing) and TCQ (Tagged Command Queuing) Explained to a full explanation on this technology. In summary, if your motherboard has SATA II ports supporting NCQ, prefer buying an NCQ-enabled hard disk drive.

I thought you should have gone one step further here or when talking about installation that the BIOS also has to be configured to AHCI mode and that it only works with Vista.

This is the way my P35 Gigabyte motherboard works. GA-P35-DS3L. Maybe you can talk about this if you do a review of the GA-EP31-DS3L.

[Gabriel Torres]

Thanks for your advice, I will take a look into that.

Gabriel.

[B.Slisk]

There is a lot more to port multipliers than what's said in the article. First of all there was no mention of the two standards used for SATA port multipliers.

Here is a bit of cut and paste:

Command-based switching, conceptually similar to a mechanical A/B switch, limits the host to issue commands to only one drive at a time. Commands to other drives will not be issued until the command queue is completed for the prior transaction. Since command-based switching only accesses one drive at a time, it does not take advantage of the higher speed 3Gb/s host link. Therefore, command-based switching is ideal for simple drive expansion where capacity is more important than performance.
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FIS–based switching offers high performance storage connections to multiple drives simultaneously. The host issues and completes commands to drives at any time. The port multiplier will direct data to any drive ready for I/O. An arbitration algorithm ensures a balanced data flow. Unlike Command-based switching, FIS-based switching allows aggregation of reads to fully use the higher bandwidth of the 3Gb/s host link and takes full advantage of the performance benefits of Native Command Queuing (NCQ) on the port multiplier, resulting in aggregated throughput of up to 300MB/second.

Then there is the fact that not all SATA controllers support SATA port multipliers, and even fewer supports both command based switching and FIS.

This kind of information is unknown to most users, and the way SATA controller manufacturers fail to draw attention to port multiplier compatibility it's easy to start thinking in terms of conspiracy. After all FIS based SATA ports multipliers are encroaching on classic SCSI territory. A place where SAS is destined to rule. It's also a fact that SAS equipment carries a price premium over SATA, so if manufacturers choose to push for SAS even where SATA with FIS base multipliers could be a alternative then it's probably because it's good for the bottom-line.

[Gabriel Torres]

Thanks a million about sharing this information with us. I will study more about that and update our tutorial accordingly.

Cheers,
Gabriel.

[snarley25]

Originally Posted by Gabriel Torres

Thanks a million about sharing this information with us. I will study more about that and update our tutorial accordingly.

Cheers,
Gabriel.

Thanks for the most comprehensive article on SATA that I've read to date.
Another benifit of using SATA drives is that if you have more than one SATA drive and at least two SATA ports on your motherboard, you can build a low-cost physical switch to boot between multiple Operating Systems. Go to
www.thesataswitch.com for detailed instructions on how to build one!