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Serial ATA, Here and Now
Xev writes "We have heard a lot about this new technology; over at HEXUS.net they have a review of a retail drive. The first on the internet, it is interesting to see the performance of the unit as well as the hotswap feature, and other new functions. Is this a solution to cheaper hot swap?"
Click here to print review
Review Title: Seagate ST380023AS Hard Drive
Reviewer: Simon Maltby
Date of Review: 30th December 2002
Sample Provided by Seagate
Introduction to SATA
Seagate UK kindly have supplied us with one of their new Serial ATA hard drives. We take a look at the new SATA format and attempt to determine what the new format means in real life. Will SATA produce any real improvement in performance?
Before we begin looking at the physical drive it is worth reading a little about the SATA format. The following extract from Seagate's web site provides us with an insight into the serial ATA standard and more importantly it's expected development path.
About the Serial ATA (SATA) format
Most desktop storage systems today use a parallel bus interface referred to as Ultra ATA/100. The parallel ATA interface has been in use on desktop systems as the mainstream internal storage inter-connect, since the 1980\'s (over 15 years!). Today\'s PCs demand higher speeds, more robust data integrity and flexibility for innovative smaller designs. Physically and electrically, the current parallel bus has run into limitations that will prevent this bus from providing higher speeds of data transfers. The move to a new technology is inevitable in the eyes of industry leaders such as Intel, Dell, Seagate, Maxtor and APT.
These same leaders formed the SerialATA.org and are highly dedicated to bringing this new technology to the forefront of today\'s PCs. Serial ATA is designed to overcome the limitations of parallel ATA while providing scalability for years to come. Setting the goal to be compatible and at cost parity with current parallel ATA drives when in volume, the SerialATA organization is promoting the adoption of Serial ATA in all systems where ATA drives are being used today.
Serial ATA... the future?
What is Serial ATA?
Serial ATA is a \"serial\" architecture as opposed to today\'s \"parallel\" ATA internal disc drive bus. Serial ATA wraps many bits of data into a packet and then at a higher speed (up to 50% higher) than parallel, transfers the packet of data down the wire to or from the host. Today Cyclic Redundancy Checking (CRC) is performed on the data being transmitted back and forth but not on the commands. Serial ATA integrates CRC on the command and data packet level for enhanced bus reliability. Cyclic redundancy code detects all single and double-bit errors and ensures detection of 99.998% of all possible errors. A Serial ATA drive can transfer data at 150MB/sec on the bus to the host system with extremely reliable accuracy and the Serial ATA interface will continue to allow scalability for a very long time.
Generation 1 Generation 2 Generation 3
Approximate Data Rate 150mb/sec 300mb/sec 600mb/sec
Approximate Bus Speed 1.5gb/sec 4gb/sec 6gb/sec
Approximate Introduction Fall of \'02 Mid \'04 Mid \'07
Additional Benefits
In addition to a faster, more reliable bus, Serial ATA improves cabling and connectors for a robust yet simpler integration. Gone are the days of bent pins and clumsy cabling and needless returned hard drives. Serial ATA cables are thinner and longer for improved system airflow and innovative system designs such as small form factor and consumer electronic boxes. Connectors are easier to snap into place without any pins but rather a blind-mate type of connection. Without the wide cables, system integrators can easily route the longer data cables (1 meter) within the system for simplicity or innovative designs.
Seagate Technology, A Native in Serial ATA Still in its early market entry stage, Serial ATA provides immediate benefits to desktop users. Serial ATA, an innovative new interface, allows continued performance growth, enhanced data reliability, and overall improved system dynamics above and beyond what Parallel can efficiently continue to provide.
A true \"Native\" Serial ATA solution offers customers the \"Real McCoy\" in Serial ATA technology. By implementing Serial ATA technology, not only on the physical layer of the drive, but also in the ATA controller link and transport layers, Seagate drives can communicate from the drive to the host directly up to the full 150MB/sec speed on the bus. In addition, the native solution incorporates command queuing, which can be a big performance boost in operating systems that can take advantage of that type of function. Some drive manufacturers may not immediately offer these \"native\" Serial ATA features on their 1st generation Serial ATA drives due to the difficulty of this integration.
The Test Drive I
The drive it\'s self looks just like any other computer hard disk drive. Consistent with other Seagate barracuda drives this one is very well built, solid and as attractive as a rectangular box of metal and plastic can be. The label clearly identifies the drive and provides setup information.
Review Model Seagate ST380023AS
Size 80gb
Speed 7,200rpm
Seek Time (Average) 9ms
Interface Serial ATA
Here is the description of the drive from Seagate\'s web site...
Seagate\'s Barracuda ATA V with Serial ATA Interface leverages the mechanics of the industry\'s quietest 7200 rpm desktop drive. The Barracuda ATA V offers 80GB and 120GB capacities with an 8MB cache for mainstream, high performance PCs, and entry-level servers. The product features all FDB motors, superior reliability and the next generation interface - Serial ATA. The SATA Barracuda includes Seagate\'s exclusive 3D Defense System and a one-year limited warranty.
Features Benefits
7,200 RPM desktop performance Improves overall PC performance
350 Gs nonoperating shock Protects drive from shock and vibration
3D Defense System Industry\'s most comprehensive drive and data protection system
DiscWizard software World\'s best disc installation software utility
SoftSonic(TM) FDB motor Quietest acoustics on any desktop drive
8-Mbyte cache buffer Improved performance
Serial ATA interface Fastest data transfer rates
The Test Drive II
SATA drives can not be connected to your computer with the standard IDE and Molex power connectors as becomes clear when viewing the back of the drive. Two new interfaces are need to use the drive. If you have a motherboard with serial ATA support you will have probably been supplied with an SATA data cable as shown below. However you will also need a Molex to SATA power conversion lead which is not supplied with either the motherboard or hard drive. I can foresee this power lead becoming a source of frustration for many people ordering SATA drives, hopefully when the drives hit the retail market the cable will be supplied with the hard drive.
Connecting the drive is very easy indeed. The SATA connectors are very well designed and will only fit the correct way round. There are no pins to bend or break as the fittings are more like USB than IDE.
Currently motherboards with SATA connectors run via the PCI bus. Some have connection via a SATA RAID controller, but our test board used a single SATA connector which is linked to a stand alone SATA controller chip. Once installed and booted the drive was displayed in the Bios taking the place of the primary IDE device. Windows XP located the drive as new hardware and the drive was fully visible. The Seagate drive is fully SMART enabled. This gives access to drive monitoring information including temperature.
Benchmarks I
Test Setup
* DFI NB80-EA Granite Bay motherboard
* P4 2.66Mhz CPU, 512MB DDR3500 RAM
* Seagate 80GB SATA150 Hard Disk Drive
* Maxtor 120GB 8MB ATA133 Cache Hard Drive on IDE
* Maxtor 60GB 2MB ATA100 Cache Hard Drive
* 2 Weston Digital 80GB 8MB Cache drives on Promise Raid Controller on Raid0
* Speedfan utility for SMART monitoring including hard drive temperature
HD Tech - Read Results Graph
The HD Tech benchmark is recognised as the most comprehensive hard drive test available. The benchmark evaluates the Hard drives performance across the whole drive regardless of how the drive is partitioned. It is common for performance to drop the further into the drive the test goes. This is due to the sectors at the end of the disk being physically further from the drives starting point.
Seagate SATA ATA150
Maxtor ATA133
The graphs above show two interesting trends. Although the computer was able to read information from the Maxtor drive faster than the Seagate drive, the opposite is true when it comes to writing data. The Seagate drive shows a consistent write speed with a few downward troughs, where as the Maxtor drive shows a few peaks in performance. Secondly although both drives show the expected reduction in read speed the further into the drive the test goes, the Seagate drive shows a slower decline dropping from circa 40k to 25k. The Maxtor drops more steeply from 50k down to 25k.
The graphs below show the results of all the HD Tech tests carried out during the review. As the benchmark requires unpartitioned drives to test writing speeds only two drives were able to be tested, the Seagate SATA and the Maxtor 120GB 8MB Cache.
Read speed average results
Write speed average results
The Seagate SATA drive did not perform as well as we had hoped in the read tests. Performance was lower than the other 8MB Cache drives whether in a raid configuration or straight forward IDE. The drive is far from being slow, but with the same 8MB Cache and the equivalent of ATA150 transfer speeds we hoped for more. Despite the average scores showing lower the Seagate drive did display better consistency across the drive as a whole and also proved significantly better in the write tests, some 30% better than the Maxtor.
Benchmarks II
Sandra Benchmark
The Sandra benchmark is less reliable than the HD Tech because it tests a partition rather than the whole drive and as we have seen performance changes depending on where on the drive the partition is located. When testing for the review we ensured that all the test drives had the same sized partition and that it was at the start of the physical disk.
The results show the same story as HD tech, although we are unable to break down the Sandra scores to establish where the Seagate drive falls down.
General Usage
Hot Swapping
An interesting attribute associated with SATA devices is that they should be \'Hot Swappable\', that means that you should be able to move devices around while your operating system is running. On the face of it this would be very useful. Care must be taken when moving hard disks around because while the internal discs are spinning damage can be caused easily. With the SATA drive installed as a non system disk we were able to disconnect the drive with windows XP running. Unlike USB device when removed, windows did not realise that the drive was no longer connected and it remained visible!
Noise
Seagate have produced a very well built drive in the ST380023AS. The casing is very solid and the mechanism well balanced. As a result it is most defiantly the quietest hard disk drive I have ever used. If you are looking for an ultra quiet drive then this one should be on your shopping list.
Reliability
The test drive was run continually for a week cycling the Sandra benchmark. Although the drive can get quite hot, rising to 45c under very heavy load, it performed without fault. SMART monitoring did not detect any problems during our testing. It should be remembered that a weeks hard testing does not give any real indication of the drives long term reliability, but we can take a great deal of comfort from the fact that the IDE Barracuda drives have proven to be one of the most reliable in the market thus far.
Price
Although SATA drives have not hit the retail market place in the UK yet The 80GB Seagate drive is expected to retail for circa £115 including VAT. This puts a small premium on the SATA format.
Conclusion
The read performance of the Seagate ST380023AS was not as good as we had hoped for. On the other hand write performance was better than we hoped for. In summary one fact is clear, the SATA interface works differently to the IDE interface and when you consider that this is a first generation SATA drive, linked to a motherboard that has the SATA interface located on the PCI bus, limiting it's potential, the overall performance is very good indeed.
The benefits of ultra fast data writing would make this drive ideal for write hungry tasks like video rendering or data backup. The Seagate drive itself is very well made and seems to be very robust. Its quiet operation makes it ideal for inclusion in a system where quietness is of benefit.
Serial ATA is in its infancy. Seagate have produced an excellent hard disk drive at the high quality end of the market place which should be very well received. I for one will be very sorry to have to part with this drive when Seagate ask for it back.
Pros
* Very Quiet
* Robust
* Very fast write performance
* Simple SATA data cable connection
Cons
* Needs power adapter (Not supplied)
* Slower read performance than expected
* SATA comes at a price premium
I didn't have a clue what serial ATA was (I'm not a hardware person), so I did a search and found The Serial ATA Working Group web site. That site has an interesting picture showing the difference in cables between parallel and serial cables here . The benefit (with the smaller cables), is that it is easier to maneuver the drives in PC cases. Other benefits of serial ATA are discussed at the web site.
Sex - Find It
Page originally available at: hexus.net
Conclusion
The read performance of the Seagate ST380023AS was not as good as we had hoped for. On the other hand write performance was better than we hoped for. In summary one fact is clear, the SATA interface works differently to the IDE interface and when you consider that this is a first generation SATA drive, linked to a motherboard that has the SATA interface located on the PCI bus, limiting it's potential, the overall performance is very good indeed.
The benefits of ultra fast data writing would make this drive ideal for write hungry tasks like video rendering or data backup. The Seagate drive itself is very well made and seems to be very robust. Its quiet operation makes it ideal for inclusion in a system where quietness is of benefit.
Serial ATA is in its infancy. Seagate have produced an excellent hard disk drive at the high quality end of the market place which should be very well received. I for one will be very sorry to have to part with this drive when Seagate ask for it back.
Pros- Very Quiet
- Robust
- Very fast write performance
- Simple SATA data cable connection
ConsFirewire is 400mbit, USB 2 is over 400mbit... but SCSI-160 is 160 mBYTE, which is considerably faster. The PCI bus is capable of 133ish mBYTEs per second throughput, significantly (8x) faster than 133mBIT. Of course, if you're going to be using SCSI-160 with any real intent for performance, you're going to be using a 64-bit 66MHz PCI bus/device (try finding quality cards that work in 32bit 33Mhz pci slots at 160). That is considerably faster, capable of transfering up to 512 mBYTES per second. That's not too bad, really, for such a general purpose I/O bus. Compare that to the cpu-ram interconnect speed of an Athlon, which is FAST at 2.1 gBYTE per second per cpu.
Firewire and USB are neat, and darned quick (quicker than most drives can go... by themselves) but 400 mBIT is really only about 40 megabytes (ok little more) per second max. Not even in the same league.
How about these for killer features: Drives that don't have share bandwidth with another device? Or even drives that don't have to slow down to match the speed of the other device on the chain? Add-in cards that can host 16 or more drives on a single IRQ? Externally? At IDE-drive prices?
SATA will scale better than parallel ATA - PATA is hard to scale given its bus nature. SATA should scale well up to at least 600MBPS theoretical throughput.
SATA has a smaller footprint than PATA, thus making it more economical to implement in mainboards where PCB space is at a premium. There is also a reduction of signal wires, so again it is more economical to use the drives.
SATA's smaller cables also allow for more creative formfactors and cabling solutions. PATA had short, wide, and ugly cabling. SATA has longer spec cabling, and its much thinner than PATA's, so cable routing is easier for OEMs.
Simply put, in its current form SATA isn't really a revolution, it's an evolution of the ATA standard, more out of convenience than anything.
------- "From bored to fanboy in 3.8 asian girls" ----------
from what i can tell, These guys are addressing that very issue, considering that they're an adopter of it.
Join the TWIT army now!
Note that the reviewer says this 80 gig SATA Seagate drive is expected to cost about 111 pounds, which is about $180. But a quick jaunt over to pricewatch.com shows one place (PC Nation) selling it for just under $140 (including shipping). They actually have the 120 gig version for about $180. Anyway, $140 isn't too out of line for an 80 gig Seagate with an 8MB buffer!
I just rebuilt my main box with the Asus A7N8X-DX, which has 2 SATA channels. I'm itchin' to try out the SATA, but can't afford to buy anything else for awhile (and the next thing I get will likely be another stick of RAM, so I can take advantage of the NForce dual memory bus). I do wonder about the usefulness of a faster IDE bus, though... The most I can get out of my ATA 100 drives is about 36 MB read time. Write time is only about 10 MB!!! Where's the fuggin 100 MB transfer speeds?
Well, I still plan on going SATA eventually (hate those damn ribbon cables). But I really hope we start to see some higher drive transfer times. What's the point of having a 3 ghz processor when the data is trickling off the drive?
(Oh, and while we're on the topic, anyone know were I can get a good, free hard drive bench prog?)
New because the old friction-fit molex power connectors suck.
Actually, it's for hot-swapability. The old molex power connectors would make your drive virtually glued in, and you'd have to jiggle it to get the contacts to fit. The new power connectors are designed for hot-swap operation. They're smaller, easier to slide in and out, and have longer ground wires which ensures the drive is grounded *before* any power is delivered. The same long-short wiring is used in the data cables, where the 3 grounding pins connect before the 4 data pins (two pairs using differential signalling) connect.
I'm not sure how you figure an adapter is less reliable. Have you *ever* had a molex power connector come apart on you unexpectedly? I count myself lucky if I can get them apart on purpose!
This early in the migration, there may be issues here and there, but when SATA becomes the standard, there will be connectors for it right on the PSU's cabling, and motherboards will support tons of SATA channels straight to the northbridge rather than ganged onto the PCI bus, and maybe hotswap drives will start to be the norm. Alright, not that last bit, but the first two should happen pretty quickly since SATA is cheaper for the manufacturer, as well as better for the consumer.
High-speed Road Trip (18.000KPH)
SATA starts at about 150MB/sec in the first generation, but don't forget that your standard 32bit 33mhz PCI slot can only do about 133 MB per second. New bus technology will need to be implemented before real performance will be seen from these drives.
I don't think these geniuses performed the hot swap correctly.
Windows should absolutely NOT report the drive with a letter after you've properly taken out the drive. This is because you are supposed to UMOUNT the fcsking drive before you do it! (There is a windows equivalent to a umount in the drive manager.) This is sort of important considering that any good OS will cache reads and write to physical disks to improve I/O speeds. Pulling a live drive out of a system is likely to create unusable filesystems on that drive.
BTW: If done correctly, you can easily remove drives from parallel ATA controllers already. In fact, you can buy caddies and mounts for hot swapping ATA/100 drives from a bunch of vendors on pricewatch.
Oh well, at least they thought they were helping. lmao!
These drives will also be the first drives available with 'digital rights management" built in. While you may get away with using them in a current MP3 player, be careful. You may find when you get them near a Longhorn system some day that M$ was serious about that "we have the right to delete anything we damn well please" provision in the click through license; even if the company who built the computer clicked it rather than you.
I'm an American. I love this country and the freedoms that we used to have.
The comparison in the review was basically useless. They compared totally different drive models, in addition to the fact that the interfaces were different. Two significant variables, so there's no way to tell if there's something inherently good/bad about SATA from this review. They should have reviewed two very similar Seagate Barracuda drives, with the interface being the main difference.
Without even having to review the drive, I'd have to say that when they get the kinks worked out of the firmware, and possibly the host/drive SATA controller(s), these drives will be just as fast in every respect as their older ATA counterparts.
I know little about SATA, but I would hope that they've fixed the addressing problem inherent in ATA. You should be able to address a large number of devices on a bus, or the benefits of SATA will be limited. SCSI will always be the choice of high-end server class machines until they can fix this problem. Also, the price of the SATA drive doesn't seem all that different from SCSI drives of the same capacity. They need to fix that too.
Or, if you want to be really mean to Windows, just pull power to the disk. It'll notice shortly and scream at you with removal notices and the like, but they can be safely ignored.
To add a disk, just plug it in. Go back to the disk management console, and click the refresh button. Windows will pick it up shortly. If it's a foreign dynamic disk, right-click it and select import - other than that, all you might need to do is assign a drive letter to it and it starts working.
Now, if you're using a REAL OS (linux), I never quite figured out how to have it dynamically reassign the hd and sd devices while the system was booted up, although I noted that it did have device removal and arrival messages in the dmesg output. If you know, please share!
Every cloud has a silver lining (except for the mushroom shaped ones, which have a lining of Iridium & Strontium 90)
Drives can't share bandwidth between other devices because SATA only allows one drive per cable.
You'd still have to contend with the bandwidth of the PCI bus in any event, so you'd be limited to the max peak throughput of 133MB/sec theoretical.
Those messages can NOT be safely ignored unless the device is marked as a removable device by the driver and write caching is turned off. Try this experiment with a firewire disk attached to a card that doesn't default to write caching off and you will pooch the disk contents (or at least whatever is not written when the device is removed, if thats a fat update then things may get interesting)
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
BTW, more heads don't buy you anything, except more heat and noise. Drives can only read from one head at a time.
The review on HEXUS.net left a great deal to be desired. HD Tach and SISandra are interesting numbers, but hardly representative of how the drive will react in the "real world." StorageReview has posted a much more comprehensive set of benchmarks on this drive at StorageReview Although StorageReview does not yet have the formal review posted, some interesting results do emerge. The SATA Barracuda V drive beats the PATA Barracuda V drive in most benchmarks. For instance, the SR High-End DriveMark 2002 goes from 285 for the PATA to 355 for the SATA. However, since the SATA drive has an 8MB cache vs a 2MB cache on the PATA drive, it's not clear how much the improved results are due to the interface versus the cache.
Unfortunately, the numbers are not yet available for the File Server DriveMark test, which might give an indication of how much the drive benefits from support for tagged command queueing like SCSI drives have.
Note that the performance results for the SCSI drives versus the Barracuda V are not a valid indication of the raw capability of the SATA interface. Virtually all of the SCSI drives are 10k and 15k RPM drives, which one would expect to be substantially faster than a 7K RPM drive such as the Barracuda.
Finally, the explanation on HEXUS.net as to why the drive slows down at the end of the HD Tach test is simply wrong. The review says that "[The slowdown] is due to the sectors at the end of the disk being physically further from the drives starting point." The reality is that the drive slows down at the end of the test because the inner rings are smaller and therefore less data passes under the head for each revolution of the disk.
I wrote Seagate sales an email earlier this month asking why the home page of their web site says, "Available now - The Barracuda ATA V" when it isn't actually possible to purchase one of those drives. They replied that the drives have been shipping to OEMs, but not to the retail channel.
The email also said that SATA Barracuda V drives were supposed to start shipping to the retail channel in late December, but I haven't seen one show up as "in stock" on CDW or pricewatch.com yet.
http://www.lostcircuits.com/advice/sata150/
Take a look at the article on that website as it actually talks about the more technical issues including why they switched the power connector.
>Serial ATA is BS. Why create a new standard? We currently have:
You know, it's hard to take someone's opinion seriously when they screw up all the figures.
>IDE (133mbit, a hack; but works well)
Not bit, byte.
>SCSI (160mbit)
Again - not bit, byte. And moreover, Ultra320 is already on the market.
>USB 2.0 (480mbit, again, a functional hack)
>firewire (400mbit).
Wow, you got two right.
>Both USB 2.0 AND firewire exceed the IO of _most_ motherboards. A 32bit 33mhz
>pci slot can only do about 132mbit.
Again - not bit, byte. Neither USB 2.0 nor Firewire exceed even bog standard PCI speeds. This is irrelevent in most cases anyways, as USB and firewire are hung off directly off the south bridge rather than the PCI bus.
Even if that wasn't the case, you're ignoring 64bit (266MB/sec), 66Mhz (266MB/sec), 64bit 66MHz (532MB/sec), and PCI-X (1066MB/sec).
>We don't need anything faster, or different. If anything, companies should be
>getting firewire directly on drives. We don't need to be forced into a
>'upgrade'.
Firewire is slower than just about every current drive interconnect, including USB 2.0, ATA/66 and above, Ultra2 and above, fiber channel, and SATA. Why on god's green earth would companies implement a slower bus?
>We have existing tech that is better. SerialATA=overpriced gear, forcing all of
>your old drives, etc, into obsolesce.
How is it forcing your current drives into obsolescence? It is signal compatible with parallel ATA, so even if manufacturers drop the old interface from their motherboards, you will be able to use your old drives with a simple, cheap adapter.
Matt