backtop


Print 72 comment(s) - last by Starcub.. on Sep 25 at 10:20 AM

Not many motherboards support new standard yet

Seagate is launching today the latest in the  Barracuda family of 7200 RPM hard disk drives. The Barracuda XT is the first drive to market that supports SATA interface speeds of up to 6Gbps. 

The 2TB monster features a large 64 MB cache, which is the largest seen on a regular HDD. However, several SSDs already use 128MB caches, and at least one controller design in the works is capable of accessing up to 256MB of cache. It is these large and fast caches that are driving SATA standards forward.
 
The latest version of Seagate's SeaTools software allows for short-stroking, in which data is stored only on the outer tracks of the drive, allowing greater access speed at a reduction in capacity. The company claims that a short-stroked Barracuda XT using 1TB of storage will be able to compete with a 10k RPM Velociraptor drive from competitor Western Digital.

The company is targeting high performance and gaming PCs, low cost servers for SMBs, and external storage applications using eSATA for the new drive. Seagate expects almost 20% of all HDDs sold in 2010 will have a capacity of  1TB or greater.

The new drive (model ST32000641AS) comes with a 5-year warranty at a MSRP of $299. It should be available at retail by the end of this week.

Despite all the enthusiasm from Seagate, it will be SSDs that see the greatest performance jump with the move to the next generation for the SATA interface. Several SSDs are already hitting the limits of SATA II when reading from their cache.

Adoption of the new SATA standard is currently slow, as the ASUS P7P55D is the only motherboard that is natively capable of support 6Gbps. Older motherboards are capable of such speeds only through the use of a PCIe adapter card.

The problem is that motherboard manufacturers are waiting for a new I/O Controller Hub (ICH) from Intel. Commonly known as a southbridge, the new ICH is expected to support new technologies such as SuperSpeed USB 3.0 and SATA 6Gbps. AMD is also working on a new southbridge to support these technologies.



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: Short Stroking
By Fat32 on 9/21/2009 2:34:09 PM , Rating: 2
quote:
As I understand it, short stroking a drive makes the outer 1/3 of the disk available, leaving the remainder of the disk inaccessible. In some areas, this is actually desired. Especially since computer performance can bottle necked on a slow performing hard drive. That means these drives would have about 680 Gigs of high performance disk area if they're short stroked. Not bad at all.


I'm afraid you're wrong. Short stroking is partitioning drive in the following manner: 1) Primary partition beginning 5-10% of the drive size 2) Extended/secondary partition is the rest 95-90%. As a result your data located on outer 5-10% surface of the disk will be much faster and require shorter movement of the head - thus it is called shortstroking. You still can use the rest of the drive, it won't just disappear.

http://en.wikipedia.org/wiki/Disk_partitioning


RE: Short Stroking
By TomZ on 9/21/2009 2:46:15 PM , Rating: 2
Using the rest of the drive will naturally also degrade the performance relative to leaving it unused, so there is a trade-off there.


RE: Short Stroking
By gstrickler on 9/21/2009 8:32:01 PM , Rating: 2
Actually, short stroking a disk drive is using any method (controller setup, partitioning, etc.) to limit the range of travel of the read write head armature. It's not a specific percentage of the range or storage capacity, nor is is necessarily the outer tracks (although those almost always gives the best performance).

Since the performance benefit is related to the reduction in maximum and average seek time, and because seek time is not linear on modern drives, short stroking will generally need to reduce the maximum head motion by 50% to have a notable performance impact. Since all modern drives record more information on the outer tracks, the "outer half" of the tracks contain about 2/3 of the total capacity of the drive. Therefore, to benefit from short stroking, you generally need to use less than 2/3 of the total capacity of the drive. If you can use less of the capacity, you may see even better performance, although the improvement will diminish as you decrease below using 20% of the total capacity.

A related technique, commonly used on 10k and 15k RPM drives, is to slightly increase the spacing between tracks, which allows reducing the "head settling" time for the "servo tracking" to lock on to a track for an accurate read/write. This must be done on the drive controller, it can't be accomplished using partitioning or other methods like short stroking can. You don't have to do this on a 10k/15k drive, but since those drives are focused on performance, it makes sense to do so. That's a major reason why 10k/15k RPM drives have lower maximum storage capacities.

It should be possible to build a 10k/15k drive with 1.5x-2x the storage capacity, but it would cost some the performance, and performance is the reason to go to a 10k/15k drive in the first place. It might still be a bit faster than a 7200 RPM drive, but it probably wouldn't be a good compromise.


"What would I do? I'd shut it down and give the money back to the shareholders." -- Michael Dell, after being asked what to do with Apple Computer in 1997














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki