An epic quest to get his hands on a SATA drive behind him, John Gillooly gets some real world performance numbers out of the future of hard drive technology.
ABOVE: The SATA version of Seagate's Barracuda V.
We had almost given up hope with this one, after months of searching high and low for Serial ATA drives we still had nothing to show. In fact we had been searching so long that we initially had to line up a preproduction motherboard from Taiwan for testing, purely because at that time there was no product that actually had SATA ports.
Our digging uncovered some startling facts; despite the fact that SATA was touted to appear mid-2002, and even after working setups were shown at IDF and Computex, drive manufacturers were holding it back and drives would not be seen until the end of the year. If they were lucky, motherboard manufacturers had a single sample drive for their entire research and development effort even though for the past few months, SATA has replaced IDE RAID as the premium component of choice on high-end motherboards.
But as the search continued word hit the street that, unbeknownst to most of the hardware community, a crate full of 120GB Seagate Barracuda V SATA drives had wound its way into the hands of a local distributor. Unfortunately, the drives did not have the expected old style Molex connectors; instead they had new SATA power connectors and hence required new cables (of which there were none in the country).
ABOVE: On the left is the data connector and on the right the new power plug.
After some hunting around, those fine techies at Xenon (www.xenon.com.au) came through, supplying us not only a SATA Barracuda V but also the cable to go with it.
Seagate then jumped in and supplied some identical parallel ATA models for comparison and the great SATA adventure began.
Driving forwardSerial ATA is a new standard designed to replace the aging Parallel ATA disk drive interface. Built around serial communication it is designed to do away with ugly ribbon cables, increase the reliability of data transfers, and provide bandwidth for future improvements in disk drive technology. It is designed as an internal interface for storage devices, sitting hand-in-hand with the increasingly commonplace USB 2.0 for external connections and the upcoming PCI-Express technology for expansion cards.
One common misconception with SATA is that it somehow replaces IDE. IDE, or Integrated Drive Electronics, refers to the design in which the drive controller is mounted not on the motherboard but on the drive itself. The IDE controller is still there, but it talks to the host controller on the motherboard via an ATA connection. To the operating system SATA looks exactly the same as Parallel ATA for the moment. Future operating systems may be able to take advantage of new features inherent to SATA.
SATA has a maximum 150MB/s data throughput, up from the 133MB/s throughput of ATA133 and the 100MB/s of ATA100. However, because it is just the interface that has been changed, the data throughput is still bottlenecked by the drive design. Hence, for the same reason that ATA133 is a Maxtor-only initiative, SATA is being pushed for reasons other than data throughput.
Using a simple two wire data connection (with some grounds thrown in), one dedicated to upstream traffic and one to downstream, SATA is set to revolutionise airflow within the case thanks to tiny cables that are a fraction of the size of the tightest of rounded parallel ATA cables.
This wire configuration also allows for drives to be hot-pluggable. A nifty pin configuration means the drives are grounded before being powered and can safely be attached and detached at will. An interesting spin on this aspect is the external SATA connector supplied with the Gigabyte GA-8INXP motherboard that we used for testing. This takes up an expansion slot and allows you to hook up and power SATA drives when they are outside the case, great for spontaneous leeching binges.
Hot-plugging is ultra cool. There is a certain thrill to be had from sitting at the testbench, watching Windows Explorer and plugging and unplugging the drive. Connection is instant -- plug in the drive, power it up and away you go. One tip though -- it would be smart to disable write caching if you want to use the drive constantly as a hot plug device and actually keep your data intact.
Currently using SATA for your primary drive in Windows XP is identical to using one on a RAID controller. When you begin the install you are asked for the driver disk, after which there is no outward appearance that the drive is different from any other.
Benchmarking cablesHard drive testing is always a tricky business. We have tested drives in three configurations, SATA, Parallel ATA and one using an ABIT Serillel SATA-to-Parallel adaptor. We chose to test with the Serillel adapter because, while most motherboards that have RAID controllers and SATA ones have enough ports for two of either drive, some recent boards have had one Parallel and one SATA controller. Therefore in order to use RAID, one of the drives must be SATA. ABIT's Serillel adaptors are quite popular solutions for this, so performance becomes an issue.
Our testbench was a mixed bunch of best and worse. The CPU was a 3.06GHz Pentium 4 with Hyper-Threading disabled to eliminate any influence on performance. We chose the Gigabyte GA-8INXP motherboard for testing as it used separate Parallel ATA RAID and SATA controllers rather than a mixed chip. The SATA controller on the Gigabyte motherboard is a Silicon Image SATALink chip.
ABOVE: On the left are Drivespeed32 results for Pararell ATA; in the middle SATA and on the right Serillel. Note the influence of serial cabling on access patterns.
We tested with two configurations. For the first IPEAK and Diskspeed32 benchmarks, we ran the drives as secondary ones to our standard Maxtor ATA100 drives. For these tests we used 1GB of dual channel DDR266 to eliminate any bottlenecking.
Then we ran some real world tests, using the drives as primary ones, installing Windows XP with Service Pack 1 and the benchmarks, defragging and then benchmarking the system. In order to increase the swapfile use and hence the amount of disk accessing done the testbench only had 128MB of RAM.
One thing to note is that these Seagate Barracuda V drives may be quiet and fast, but they do get very hot (almost untouchable at times) and so we recommend a few fans nearby, as we ended up doing while testing. At least, when we weren't using the drives to heat our coffee for between-benchmark drinks.
Our selection of benchmarks has a couple of new programs and some familiar ones. Firstly we used SiSoft Sandra 2003 to get theoretical burst speeds for the drives, but as Sandra is at bes
Issue: 137 | June, 2012