Western Digital Caviar SE 2500JS HDD - SATA vs. SATA-II

Today we're taking a look at one of Western Digital's latest hard drives to hit the market. The WD2500JS is a 250GB hard drive with a 7,200RPM spindle motor which supports the new SATA-II interface allowing for a theoretical maximum 300MB/s transfer speeds. Read on as take a close look at the drive and compare it against a high-performing SATA-150 drive to find out the performance differences between SATA and SATA-II.
| Oct 2, 2005 at 11:00 pm CDT
Rating: 80%Manufacturer: Western Digital


IntroductionUnless you have been living under a rock, you will be no stranger to the Serial ATA standard that has become the new medium for mass storage connection to the PC. Serial ATA standards have now started to produce in mass on motherboards, with upwards of 4 ports standard on Intel, ULi, SIS and nVidia Southbridge's - not to mention the amount of additional controllers being added by motherboard makers, its not uncommon to see 6-8 SATA ports per motherboard.Serial ATA's main claim to fame is serial transfer of data from the I/O logic to the HDD controller chips. Serialisation means using serial communication architecture, similar to that which was introduce by RAMBUS for its RDRAM memory. Serial ATA Generation 1 is able to transmit at a theoretical 1.5Gbps (or 150MB/s) between the Southbridge and the onboard system controller of the Hard Disk, however, limits in magnetic storage doesn't permit the HDD to actually take advantage of this - speed wise, SATA is no more faster than ATA-133 HDD's until NCQ come along.NCQ or Native Command Queuing is fairly new to the Serial ATA standards. NCQ allows the HDD to smartly access data out of order rather than having to go though an order state to grab the required files, which can be located in different parts of the drive platers.Another feature of Serial ATA is the reduced size of the cables while lengthening them at the same time. SATA cables are only 7 wires wide, as opposed to IDE which are 80 wires across. IDE also limits the size at just over 60cm long while Serial ATA can go up to 1 meter before a repeater is needed to power re-transmit data over longer cables.Serial ATA Gen 1 did make some changes, now we have received Serial ATA Generation 2. SATA-II as it is known speeds the data transmission from 150MB/s up to 300MB/s between the HDD and the Southbridge chipset. nVidia and Intel are the first to offer this in their south bridges, with ULI, SiS and ATI soon to follow.Today we are looking at the first SATA-II HDD to cross our labs, Western Digital's Caviar SE WD2500JS and comparing it to a high-performing Seagate SATA 7200.8 HDD.


Specifications of the Western Digital Caviar SELet's take a quick look at the drive specifications before taking a closer look at the drive.Performance SpecificationsRotational Speed: 7,200 RPM (nominal)Buffer Size: 8 MBAverage Latency: 4.20 ms (nominal)Seek TimesRead Seek Time: 8.9 msTrack-To-Track Seek Time: 2.0 ms (average)Full Stroke Seek: 21.0 ms (average)Transfer RatesBuffer To Host (Serial ATA): 300 MB/s (Max)Buffer To Disk: 748 Mbits/s (Max)Physical SpecificationsFormatted Capacity: 250,059 MBCapacity: 250 GBInterface: SATA 300 MB/sBytes Per Sector: 512User Sectors Per Drive: 488,397,168Servo Type: EmbeddedPhysical DimensionsHeight: 26.1 mm (Max)Length: 147 mm (Max)Width: 101.6 mmWeight: 0.6 kg (+/- .082 kg)Pretty standard specifications except for the 300MB/s transfer speeds but will it make a difference in the real-world?


Features of the Western Digital Caviar SEBefore we jump into what everyone wants to see, the benchmark data, we best have a look at the drive itself. The Caviar SE and SE16 are Western Digital's first to market SATA drives supporting the new SATA-II spec line. The drives themselves come in 160GB, 200GB, 250GB and 300GB models.Western Digital has two separate models, the Caviar SE and the Caviar SE16. Both drives have almost identical specifications, the only difference is the cache sizes - the SE has an 8MB cache, and the SE16 has, you guessed it, 16MB.
Looking at the drive, there is very little difference in physical characteristics that would distinguish the drive from any of the other Western Digital drives on the market. There are no markings on the drive that indicate SATA-II support unless you take a look at the jumper settings.
The back of the drive also resembles the back of all the WD SATA drives on the market. Western Digital is the only manufacturer that supports both SATA power connector and the legacy 4 pin Molex power connector on the one drive. A word of warning, don't use both SATA and legacy power connectors together or you will damage the drive.While there are no Master/Slave settings for SATA drives, there is a bank of jumpers on the back of the drive. Each controls a set of functions. Here you can disable SATA-II support and revert to SATA-150, disable Spread Spectrum clocking and a few other features that weren't in the manual at this stage.
The bottom of the drive it totally clean. Western Digital puts the controller circuit chips on the inside of the PCB between the HDD casings. In all we would like to see the chips, as they could be actively cooled in a hot running system.

Benchmarks - Test System Setup and HD Tach

Test System SetupProcessor: Intel Pentium 4 660 (800MHz FSB) (Supplied by Intel)Memory: 2x Corsair 512MB DDR2-800 (Supplied by Corsair)Motherboard: ASUS P5WD2 Premium (Supplied by ASUS)Graphics Card: ASUS Radeon X800XT Platinum (Supplied by ASUS)Operating System: Microsoft Windows XP SP2For our testing we used the ASUS P5WD2 Premium motherboard with the ICH7-R SB. Only Intel and nVidia have full SATA-II standard support in their latest chipsets. SiS currently has SATA-II on the cards as does ULi and ATI. VIA has not announced any new SATA-II support yet.Both of our test drives were connected to the system through the ICH7-R SB and it's worth noting Seagate's current generation of SATA drives (7200.8) offer pretty good performance (as discussed here in our review of the drive earlier this year) so the Western Digital SATA-II drive will be under some pressure to perform well.We would have liked to test in RAID 0 but unfortunately we only received one drive from Western Digital so we'll just be testing with single drives.Let's get started!HD TachVersion and / or Patch Used: 3.0Developer Homepage: http://www.futuremark.comProduct Homepage: http://www.simplisoftware.com/Public/index.php?request=HdTach /Buy It Here
HD Tach has been around for a long time and is excellent when it comes to testing hard drive performance. It is also a very handy program when it comes to testing the controller used on particular motherboards. Tests such as Read, CPU Utilization and Burst are available at a click of the button and give you a good idea of how the hard drive can perform from system to system.
Despite a higher Host to drive transfer speed of SATA-II, it still has no real world advantage.

Benchmarks - PCMark05

PCMarkVersion and / or Patch Used: 2005Developer Homepage: http://www.futuremark.comProduct Homepage: http://www.futuremark.com/products/pcmark04/Buy It Here
PCMark is a multipurpose benchmark, suited for benchmarking all kinds of PCs, from laptops to workstations, as well as across multiple Windows operating systems. This easy-to-use benchmark makes professional strength benchmarking software available even to novice users. PCMark consists of a series of tests that represent common tasks in home and office programs. PCMark also covers many additional areas outside the scope of other MadOnion.com benchmarks.
PCMark05 doesn't show any real advantage to SATA-II.

Benchmarks - File Copy Test

X-Bit Labs File Copy TestVersion and / or Patch Used: 0.59Developer Homepage: http://www.xbitlabs.comProduct Homepage: http://www.xbitlabs.com/articles/storage/display/fc-test.html
X-Bit Labs File Copy Test is a real world benchmark used to measure the performance of IDE subsystems. In this test, we time how long it takes to copy 2.3GB worth of data (four x 590MB files) onto the same hard disk drive with File Copy Test program optimizations disabled to help provide the most accurate time possible.
Here we see that the file copy on the drive that supports SATA-II does have a fair advantage over SATA-I NCQ.

Final Thoughts

Final ThoughtsSerial ATA has taken off as the standard for mass storage; it's only a matter of time before ATAPI devices will start showing up on SATA, allowing a much broader range of transfer rates for DVD-R units.Serial ATA has had some teething issues, such as getting wide range support, as well as adding features that would distinguish it from Parallel ATA architecture but Serial ATA-II has finally done this.Serial ATA-II adds speeds of 300MB/s between the host to drive buffer as well as full support for hot plug, which allows for using HDD's as swappable media - no need for rebooting, much like USB.In our testing, Serial ATA-II running at full speed doesn't offer any great speed advantage over the SATA-150 drives, so until the magnetic storage components are replaced with high speed non-violate memory, we won't see much in terms of speed upgrades with SATA-II at its current form.Overall the speed of the Western Digital drive isn't impressive as a single drive not in RAID, but the additional features make SATA all the more enticing as the new storage interconnect standard and in a RAID 0 array we've seen SATA-II drives really shine. Western Digital's implementation of SATA-II is good and drive is built to typical high-quality WD standards however unfortunately our performance benchmarks were not as impressive as we imagined they would be.- ProsSATA-II supportMolex power connection optionQuiet operationVery well priced (around 44 cents USD per GB at time of publishing)Good performance but not spectacular- ConsNo real advantage over SATA as a single drive- Current Pricing The Western Digital 2500JS HDD is for people building a new system with SATA-II support and want a very affordable yet decent drive with plenty of space and is not for people thinking of upgrading from a single SATA to SATA-II drive expecting to see massive jumps in performance.Rating - 8 out of 10

Last updated: Apr 7, 2020 at 12:26 pm CDT

PRICING: You can find products similar to this one for sale below.

USUnited States: Find other tech and computer products like this over at Amazon.com

UKUnited Kingdom: Find other tech and computer products like this over at Amazon.co.uk

AUAustralia: Find other tech and computer products like this over at Amazon.com.au

CACanada: Find other tech and computer products like this over at Amazon.ca

DEDeutschland: Finde andere Technik- und Computerprodukte wie dieses auf Amazon.de


We openly invite the companies who provide us with review samples / who are mentioned or discussed to express their opinion. If any company representative wishes to respond, we will publish the response here. Please contact us if you wish to respond.
Go to top of the page