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Western Digital Raptor WD1500ADFD - Bigger, Faster, Stronger
Date: Jan 19, 2006
Author: Dave Altavilla
Intro and Tech Specs


Western Digital has earned themselves quite a reputation in the Computing Enthusiast market with their line of Raptor hard drives.  Originally targeted as "Enterprise class" SATA variants of what WD had historically brought to market for high-end SCSI server storage solutions, the 10K RPM Raptor was an overnight success for end user performance freaks, including many of us here at HotHardware.com.  WD's first iteration of the drive was a somewhat overly-svelte 36GB version that came outfitted with an 8MB cache.  And it was actually not what one would term a "native SATA" drive, with a Marvell PATA to SATA bridge chip handling calls for the drive's SATA 1.5GBps interface back into what was essentially a PATA circuit block.

The second coming of the Raptor (yes it was near god-like to some), marked a welcomed increase in capacity to 74GB, with a pair of 36GB platters inside.  The drive retained the bridge chip for its SATA interface, but updated firmware along with quieter operational acoustics and overall better performance, just offered more of a good thing.  Plugging a pair of Raptor WD740s into a RAID 0 array was becoming commonplace in many Gaming Rigs and high-end Workstations.  Regardless, the insatiable need for more storage capacity marches on, along with the need-for-speed; it almost goes without saying.  With huge capacity drives like Hitachi's 7K500 entering the market, as well as new advances in 3GBps SATA interfaces speeds and other technologies like NCQ (native command queuing), Western Digital had to answer the call.  Their answer?  The new Raptor WD1500 series, which we'll be evaluating today.

Western Digital Raptor WD1500ADFD and WD1500AHFD
Specifications & Features
Physical Specs -
- Capacity 150GB
- Interface:  SATA 150 MB/s
- Spindle Speed:  10,000 RPM
- Cache Buffer:  16MB
- Number Of Platters:  2
- Number Of Heads: 4
- Bytes Per Sector: 512
- Height 1.028 Inches
- Length 5.787 Inches
- Width 4.00 Inches
- Weight 1.81 Pounds

Performance Specs -
Seek Times

- Read Seek Time 4.6 ms
- Write Seek Time 5.2 ms (average)
- Track-To-Track Seek Time 0.4 ms (average)
- Full Stroke Seek 10.2 ms (average)
Transfer Rates
- Buffer To Host (Serial ATA) 1.5 Gb/s (Max)
- Buffer To Disk 84 MB/s (Sustained)
Idle Mode 29 dBA (average)
- Seek Mode 0 36 dBA (average)
Power Dissipation
- Read/Write 10.02 Watts
- Idle 9.19 Watts
- Standby 2.66 Watts
- Sleep 2.48 Watts

Features -
- Native Command Queuing (NCQ)
- RAID-specific, time-limited error recovery (TLER) — a feature unique to WD, prevents drive fallout caused by the extended hard drive error-recovery processes common to desktop drives.
- Rotary Acceleration Feed Forward (RAFF™) — optimizes operation and performance when the drives are used in vibration-prone, multidrive systems such as rack-mounted servers or network storage.
- FlexPower™ — connector technology that accepts power from either industry-standard or new SATA power supplies.

5-year warranty
600,000 hour MTBF - Raptor X
1.2M hour MTBF - Raptor WD1500ADFD

Standard Western Digital
Raptor WD1500ADFD

(cover off)


Western Digital Raptor X
With Clear Cover Cas






NCQ, TLER and RAFF - Where's our acronym dictionary anyway?

In addition to the new Raptor WD1500's obvious enhancements in capacity and a larger cache, the drive boasts a few new additions to its feature-set, some of which are specifically targeted at RAID applications.  You've probably read a fair amount regarding Native Command Queuing, so we won't dwell too much there except to say that the technology has limited benefits currently, unless your usage of the drive will be based in rigorous multi-threaded scenarios where requests on the hard disk can actually expand such that the queue depth and ordering need to be more efficiently managed. It's within situations like these that NCQ can very much have an impact by ordering multiple simultaneous commands from the OS and thus reducing associated rotational latencies pulling data from the disk.  Regardless, as time goes on NCQ will have a more significant impact on performance and as such it's a nice feature to have for its future-proofing benefits.

Western Digital has also incorporated RAID-specific TLER (time-limited error recovery) and RAFF (rotary accelerated feed forward) technology with the Raptor WD1500.  TLER is method of signaling the system RAID controller in the event that an error recovery process is taking longer than time-out specifications allow.  This prevents the RAID controller from dropping the drive from the array during this period.  This feature doesn't do much for you in a single drive configuration though and in fact TLER is turned off by default with the drive, only available to toggle on with a special utility we have yet to receive from WD. 

RAFF (Rotary Acceleration Feed Forward) is a method of sensing RV (rotational vibration) of other drives in a multi-drive installation and then compensating for it, controlling drive head position and keeping within a safe tolerance during read and write operations.  This feature supposedly can increase performance significantly, avoiding costly retry efforts where the drive head is ever so slightly bumped off the track, resulting in performance degradation.  We weren't able to specifically prove out this claim but it goes without saying that RAFF is a welcomed feature, especially for those of us considering RAID array setups with this new breed of Raptor.

A Closer Look, Acoustics, Thermals And Test Setup


Hard Drives can be sexy, right?  If that's the case then may we suggest getting out a bit more?  There's this bright yellow thing in the sky sometimes that's kind of nice.  People are OK too, really.  All kidding aside, we have a bit of show-and-tell for you here and Western Digital decided to up the ante a bit on appearance as well, with a version of the new Raptor dubbed "Raptor X".

A Closer Look At The New Raptor WD1500 Series
Native SATA 150, 10K RPM, 150G, 16MB Cache, NCQ



First, what might not be obvious to you, resides in the picture of the back side of the drive above.  The absence of the tiny Marvell 88I8030 Parallel ATA to SATA bridge chip indicates this version of the Raptor has true "native" Serial ATA electronics within.  Also above we've given you a look at Western Digital's special SATA cable assemblies that have a fantastic locking mechanism providing much better secured connectivity with the cable at the drive end of the connection.  The other end needs to remain a standard SATA plug to maintain cross-platform compatibility, but regardless the drive side of the cable has a far superior connector design, even if it's only available by WD and fits only on their drives.  And can you blame them?  These cables will be bundled in with full retail box versions of the drive but not with bare OEM units.

Then of course, last but not least is the Raptor X, pictured in all its geek-sexy glory.  The only thing that differentiates this drive from the non-windowed version you see above, is its clear polycarbonate window.  This version of the drive retails for $50 more than the standard Raptor WD1500 ($349 versus $299 MSRP) but for those of you with cold-cathode lighting, windowed side-panels and low-rider-pimped-rig-techno-bling, it certainly is macktastic yo! Errr, or something like that anyway.  It is pretty cool to watch the platters spin with the heads tracking back and forth.  Just make sure you're super careful not to scratch the window.  The material does seem to be rather prone to scratches from even the slightest abrasion.

A Note On Acoustics And Thermals:

We've spent many hours testing these new WD1500 Raptors and also took note of the drive's performance relative to thermal radiation and noise levels.  Suffice it to say that this drive is very much on par with the WD740GD Raptor drive in both of these areas.  We actually took an infrared temperature meter to the WD1500 drives and compared surface temps under load versus the WD740 and a pair of 250GB Maxtor DiamondMax 10 drives.  Both the WD740 and WD1500 series Raptors recorded max temps in the 105o - 109oF range under a full load HD Tach Write test.  The WD1500 actually exhibited the highest reading in one area of its casing where temps hit a peak of 109oF, while the WD740 topped out around 105o - 107oF.  The DiamondMax 10 drives were the coolest of the bunch, but not by much, registering in at 102oF or so.  All of our testing was done on an open air test bench, so thermals enclosed in a system chassis will undoubtedly be higher if proper air circulation isn't supplied.  Regardless, we would characterize both the WD1500 and WD740 drives as middle of the road in terms of their thermals.  They're 10K RPM drives that generate a bit more heat than most 7200 RPM drives but the variance is not that significant.

On the acoustics side of the equation, subjectively we would offer that the WD1500 and WD740 are also very similar.  These drives do have an audible whine on spin up and spin down that is perhaps more pronounced than many 7200 RPM drives but again we wouldn't classify their noise levels as offensive, even for those of you that are hell-bent on a super quite system.  By comparison, the 7200RPM DiamondMax 10 drives we tested along side the WD1500 Raptors, list a 25 - 38db acoustic specification, while Western Digital lists 29 - 36db (idle to seek noise levels) for the WD1500 series.  We would concur with these specs.  The Raptor WD1500 has ever so slightly louder spindle and motor acoustics than some 7200 RPM drives but under seek operations the heads are relatively quiet.  These new Raptors are pretty much middle of the pack as far as noise is concerned as well.  At least on our humble opinion.

Test System Specifications
AMD Athlon 64 FX-60 (2.6GHz)

Asus AN832-SLI
(NVIDIA nForce 4 SLI X16)
(On board nForce 4 MCP MediaShield Storage Controller)

2x512MB Corsair PC3200
CL 2-2-2-5

GeForce 7800 GTX
On-board Ethernet
On-board Audio

Western Digital "Raptor" WD740GD 74GB HD X2
10,000 RPM SATA 150
Western Digital "Raptor" WD1500ADFD 150GB HD X2
10,000 RPM SATA 150
Western Digital "Raptor X" WD1500AHFD 150GB HD X1
10,000 RPM SATA 150
Maxtor DiamondMax 10 6B250SO 250GB HD X2
7200 RPM SATA 150
Western Digital "Raptor" WD360GD 36GB HD - OS Drive
10,000 RPM SATA 150

Windows XP Pro SP2
nForce 4 Drivers v6.82
NVIDIA Forceware v81.98
DirectX 9.0c

Our test methodology for all drives we benchmarked was fairly straight forward.  In tests like HD Tach, we installed the drives and left them completely unpartitioned and unformatted.  This allowed us to utilize HD Tach's Write performance test feature as well.  For our SANDRA File System and PCMark05 Hard Disk tests, we were required to partition and format all volumes whether in single or RAID 0 array configurations.  For single drives tests we set up a standard Windows XP NTFS partition, and then formatted the drives leaving them completely blank.  For RAID arrays we utilized nVIDIA's RAID BIOS menus to configure a striped RAID 0 array with the default "maximum performance" 64K stripe size.  Partitions were then configured with a 16K cluster size, formatted and again left completely blank for testing.  Our OS and all benchmarks were installed on a separate Western Digital Raptor WD360.

SiSoft SANDRA File System Tests


We began our testing with SiSoftware's SANDRA File System benchmark module. This test's method of hard disk performance analysis it what we would consider a "light duty" consumer-level evaluation tool.  The folks in IT would have your head for recommending a drive based solely on SANDRA File System test results.  However, the benchmark is a popular utility within the performance PC enthusiast community and it does give a decent quick swag at high-level throughput characteristics of the total storage subsystem, which of course includes HD controllers and other associated system components.

Preliminary Benchmarks With SiSoft SANDRA 2005 SR2

SANDRA's Random, Sequential and Buffered read statistics show a commanding lead for the new WD1500 Raptor.  We'd place more stock in the Random and Sequential Read tests since standard desktop and gaming application file access places moderate to high loads in these areas.  The Raptor WD1500 is showing a 42% Random Read advantage over its smaller sibling and about 35% over the Maxtor drive, with about 19 - 25% better performance in Sequential Reads.


Write performance of the Raptor WD1500 scales about the same with the exception of Buffered Writes which are pretty much all over the map.  Again buffered reads and writes are representative of performance with short bursts of data and thus not as representative of typical real-world performance, though Maxtor's DiamondMax 10 perhaps makes more efficient use of their on-board cache memory than the Raptors do according to this benchmark.

SANDRA's Drive Index rating is probably the most familiar score to many of you reading here and clearly this benchmark shows the new Raptor WD1500 series as the leader far and away, whether in single drive or RAID 0 installations.  For what it's worth, this is the fastest RAID 0 performance we've recorded with SANDRA to date, utilizing standard SATA hard drives.

PCMark05 Hard Disk Drive Tests


Next up is PCMark05 from FutureMark Corp.  We specifically used only the HDD Test module of this benchmark suite to evaluate all the drives and configurations we tested versus the new Raptor WD1500.  We consulted Futuremark's white paper on PCMark05, for an understanding of what this test component entails and how it calculates its measurements.

Futuremark's PCMark05

Courtesy, FutureMark Corp. -
For these tests, we use RankDisk, an application developed and copyrighted by Intel. In our testing, we found RankDisk to be suitable for a neutral benchmark. RankDisk is used to record a trace of disk activity during usage of typical applications. These traces can then be replayed to measure the performance of disk operations for that usage. RankDisk records disk access events using the device drivers and bypasses the file system and the operating system's cache. This makes the measurement independent of the file system overhead or the current state of the operating system. In replaying traces, RankDisk always creates and operates on a new "dummy" file. This file is created in the same (or closest possible) physical location of the target hard disk. This allows the replaying of traces to be safe (does not destroy any existing files) and comparable across different systems. The traces contain different amount of writing and reading on the disk; total ratio in the HDD test suite disk operations is 53% reads and 47% of writes.  The following input traces are used:

Windows XP Startup:  This is the Windows XP start trace, which contains disk activities occurring at operating system start-up. The test is 90% reading and 10% writes. This trace contains no user activity.

General Hard Disk Drive Usage:  This trace contains disk activities from using several common applications.
These are:
- Opening a Microsoft Word document, performing grammar check, saving and closing
- Compression and decompression using Winzip
- Encrypting and decrypting a file using PowerCrypt
- Scanning files for viruses using F-Secure Antivirus.
- Playing an MP3 file with Winamp
- Playing a WAV file with Winamp
- Playing a DivX video using DivX codec and Windows Media Player
- Playing a WMV video file using Windows Media Player
- Viewing pictures using Windows Picture Viewer
- Browsing the internet using Microsoft Internet Explorer
- Loading, playing and exiting a game using Ubisoft™ Tom Clancy's Ghost Recon
The General Usage trace is 60% reads and 40% writes.

Virus Scanning:  Virus scanning is a critical task in today's PC usage. As the major bottleneck of scanning
viruses is in hard disk activity, it is reasonable to include virus scanning as a HDD test. The test consists of HDD
activity of scanning 600MB of files for viruses. The Virus Scanning test is mostly disk reading (99.5%).

Our detailed PCMark05 tests show the Raptor WD1500 significantly ahead of the WD740 Raptor, and even more so versus the 7200RPM DiamondMax 10.  Furthermore RAID 0 configurations with the WD1500 show an increase in performance for WinXP start-up and general usage on the order of 20-25% (RAID 0 versus single drive performance compared between just the WD1500 series installations).  Our PCMark05 Virus Scan test, again a test that is representative of almost exclusively read performance, the clear winners are the 16MB cache enabled drives, in this case the Raptor WD1500 and the DiamondMax 10. 

PCMark05's overall Hard Disk Drive test scores are representative of a weighting of two other tests in addition to the tests we've given detail for above, specifically File Write and Application Loading.  PCMark05 shows the Raptor WD1500 to be ~ 20% faster than the Raptor WD740 and ~ 38% faster than the DiamondMax 10 drive.  RAID 0 performance scales down a bit to the 10 - 28% range respectively.

HD Tach Benchmarks



The four HD Tach metrics that we sampled for each drive are Random Access, which is largely dependent on spindle speed of the drive, Read Average, Write Average and Burst Read throughput.  Again Read and Write Average scores are what we would consider the most meaningful to the end user.  Whereas Burst Read is typically tied the drives on-board caching and SATA interface speed.

Single / RAID 0 Performance
Performance with HD Tach

Simply put, the new Raptor WD1500 once again "kicks it up a notch" on its little brother WD740 and pretty much out-classes the DiamondMax 10, as far as Average Read/Write performance goes.  Burst Read performance did fall slightly in favor of the Maxtor drive but only by a hair.  Perhaps a firmware tweak or two down the road will bring even better burst performance for the Raptor WD1500, but then again slightly higher burst throughput typically doesn't equate to higher tangible end user performance.

Quake 4 Level Load Time Tests


Practical? Yes.  Indicative of a complete end user experience? Probably not.  But regardless we've included a gaming test where we simply measure the time it took to load up Quake 4's first level when starting a new game for the first time.  In this test we re-booted the system each time since Quake 4's engine tends to cache levels a bit even though you have dropped out to the desktop.  The scores below represent worst-case level load times based on a reboot of Windows XP and a few minutes of stabilization time, waiting for XP to load all its associated drivers, etc.

Single / RAID 0 Performance - Quake 4 Level Load
Gaming Load Times Examined


So there you have it, a RAID 0 array has very little impact on actual level load times in this particular game engine, versus a single drive array.  Beyond that we see the prowess of the Raptor WD1500's 10K RPM spindle speed and it's 16MB cache buffer.  A few seconds spared waiting for levels to load may afford you one more death-dealing exchange with the baddies but perhaps what may be more important would be potentially more responsive texture and map loads during live game-play.

Benchmark Analysis Wrap-up And The Rating


Benchmark Analysis:
Hands down the Western Digital Raptor WD1500ADFD and its windowed counterpart, the WD1500AHFD, are the fastest standard SATA desktop hard drives we've tested thus far.  The WD1500 drives out-paced their predecessor, the Raptor WD740GD, in every single test by a comfortable margin and offered a significantly more impressive performance profile over the DiamondMax 10 7200 RPM drives we tested as well, which historically have been competitive alternatives with their 16MB caches and NCQ. 


In short, we'd challenge any other drive manufacturer out there today to offer a standard SATA drive that can compete with this new Western Digital Raptor in terms of performance.  The WD1500 series Raptor is simply, in a word, impressive.  Those of you looking for the fastest file system, OS and application performance will be thoroughly impressed with Western Digital's third generation Raptor.  It may be smallish versus some of the larger current generation SATA drives on the market, but plugged into a high-end system as the main OS drive and supported by a second storage element (internal or external) for mass storage, this new Raptor makes all the sense in the world.  Sports Car-like random read/write performance coupled with a 10K RPM spindle speed, 16MB cache and the latest storage command queuing algorithms, adds up to enthusiast-class storage excellence; not to mention what these drives could do in a server environment, as lower cost alternatives to traditional SCSI 320 offerings.  After all, WD does technically classify the Raptor WD1500 as a "high performance enterprise" drive, so we can't forget that target market either can we? (wink, wink)

With an MSRP of $299 for the windowless WD1500 and $349 for the Raptor X (street prices are already dipping below these marks), we're confident the drives will be a big hit in the mainstream Performance Desktop market.  We can't say enough about the Raptor WD1500, the drives are just that good.  With comparatively higher costs versus many 7200 RPM drives, to the tune of almost 2 times the price in some case,  we'll have to stop short of a perfect score for the new Western Digital Raptor WD1500 series but you can bet your barracuda we're giving them an Editor's Choice.

_Fastest SATA drive we've ever tested
_16MB cache buffer
_10K RPM
_Relatively cool and quiet
_Tradition of reliability for the Raptor series
_A trade-off of speed versus capacity

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