Momentus 5400.6 & Scorpio Blue: Seagate & WD 2.5″ HDDs at 500GB

The current flagships of WD’s and Seagate’s 2.5″ notebook drives go head to head in our review. 5400RPM, 500GB on two little platters with areal density at nearly 400 GB/inch: What performance and noise do the Momentus 5400.6 500 and Scorpio Blue 500 offer?

March 2, 2009 by Mike Chin

Products	Seagate Momentus 5400.6 500GB ST9500325ASG WD Scorpio Blue 500GB WD5000BEVT
Manufacturer	Seagate and Western Digital
Market Price	US$100~130

In the 15 months since our last review of a 2.5″ notebook drive, they more than doubled in capacity, dropped signicantly in price, and moved entirely to the SATA interface. Their use in small desktops is now much more common, so SPCR is no longer alone in encouraging such use. The era of nettops is on us, and 2.5″ notebook drives are frequently used in place of standard 3.5″ desktop drives for their smaller footprint and lower power/heat disspation. Since they are usually quieter than 3.5″ desktop drives, this is a good trend for noise-conscious computer users (although as our review of the Dell Studio Hybrid mini PC showed, how a 2.5″ drive is mounted in the chassis has a substantial impact on propagated noise).

The two 500GB 2.5″ drives under review here are the current capacity flagships of the respective brands, Seagate and Western Digital. Samsung and Hitachi reached 500GB capacity a little sooner, but they did so with 3-platter designs. With Hitachi, this resulted a physically thicker 12.5mm drive rather than the standard 9.5mm. The latter dimension is necessary for a drive to fit into a standard notebook.

The half-terabyte capacity on the Seagate and WD drives is achieved with just two platters, so both drives adhere to the standard notebook drive form factor. The areal density is 394 GB per square inch, according to Seagate. Given the much smaller platter size, this is probably at least as high as the 375 GB/platter achieved in their 1.5 TB 4-platter 3.5″ desktop 7200.11. Refinements in perpendicular recording helps achieve such high density. These 2-platter designs provide several advantages over the 3-platter competition:

• Higher areal density means higher throughput speed.
• Fewer platters means lower complexity and manufacturing cost.
• Fewer platters also means lower power usage and cooler operation, especially important for battery-powered mobile devices.

We’ll examine each drive in turn, then compare and contrast the two.

SEAGATE MOMENTUS 5400.6 500GB

Seagate Momentus 5400.6 500GB (from Seagate’s web page)
FEATURE & BRIEF	Our Comment
8-MB cache delivers fast performance.	Does not seem so much for a 500GB drive.
SATA 3.0Gb/s interface with Native Command Queuing	The highest SATA bus speed currently available, but NCQ is not really useful for desktop computing.
Up to 1000 Gs of Shock Resistance in non-operating mode	Seems high, but it’s not really. If the drive falls 1m and the impact lasts less than half a millsecond (quite plausible with a hard floor and rigid drive casing), then 1000G will be reached. (Thanks to Chris Friesen for this insight.)
Designed-in G-Force Protection technology for added durability and reliability during accidental drops	Senses when the drive is in free-fall, moves heads off the platter and locks them in place within 0.3 second.
QuietStep™ technology enables ultra-quiet load/unload acoustics.	Better than previous generation Seagate laptops?
Seagate laptop power management technology and ramp load features that remove the head from the disk during idle to improving idle power consumption	OK, we’ll measure and see if there’s any change from previous drives.
5-year limited warranty	Standard for Seagate packaged drives.

 

WD SCORPIO BLUE 500GB

WD Scorpio Blue 500GB (from WD’s web site)
FEATURE & BRIEF	Our Comment
Massive capacity	No argument there.
Reliable and rugged – WD’s ShockGuard™ protects drive mechanics and platter surfaces from shocks. SecurePark™ parks the heads off the disk during spin up, spin down, and when the drive is off.	Sounds familiar, doesn’t it?
Quiet – WhisperDrive™ combines state-of-the-art seeking algorithms to yield one of the quietest 2.5-inch hard drives on the market. These algorithms also optimize the way a drive seeks for data, which significantly improves power consumption.	OK, we’ll be testing for acoustics to verify.
Fast and efficient – 5400 RPM spin speed, 12 ms access time and up to 3 Gb/s SATA interface speed.	OK
Tested for compatibility – We perform tests on hundreds of systems and a multitude of platforms in our FIT Lab™ and Mobile Compatibility Lab to give our customers confidence that our drives will work in their systems.	Sounds good, but we’d expect all the drive makers to do the same, no?
3-year limited warranty	Standard for WD Blue.

SPECIFICATIONS

The specifications of the particular drives are compared below. There isn’t a lot to differentiate them, and the most important parameters — transfer rate and acoustics — are cited differently, so a quick comparison is not simple. The difference in the acoustic specs are interesting. Bels, used by Seagate, is a measure of sound power. Decibels A-weighted (presumably at 1m distance) is a measure of sound pressure level. A sound that measures 2.4 bels generally measures considerably lower than 24 dBA@1m SPL, so the Seagate would appear to be quieter. One would not expect such differences from such similarly spec’d drives. We’ll see from our own measurements soon enough.

Specifications: Momentus 5400.6 500GB & WD Scorpio Blue 500GB (from their respective data sheets)
Model	Seagate Momentus ST9500325ASG	WD Scorpio WD5000BEVT
Capacity	500 GB	500 GB
Cache	8 MB	8 MB
Disks / Heads	2 / 4	2/4
Interface	SATA 3Gb/s	SATA 3Gb/s
Spindle Rotation Speed	5,400 RPM	5,400 RPM
Latency	5.6 ms	5.5 ms
Random read seek	14 ms	12 ms
Maximum Transfer Rate Internal (Mb/s) External (MB/s)	1175 300	Host to/from drive: 106 MB/s (maximum)
Weight	98.8 g	117 g
Operating Temperature	0 – 60°C	0 – 60°C
Power Requirements (W): Seek Read / Write Idle / Standby	1.54 2.6 / 2.85 0.8 / .23	n.a. 2.5W 0.85 / 0.25
Acoustics: Idle / Seek	2.4 / 2.6 Bel	24 / 26 dBA

TEST RESULTS

Our samples were tested according to our standard
hard drive testing methodology. The significant change in our testing procedure is that as of mid-2008, we’re conducting most acoustics tests in our own anechoic chamber, which results in more accurate, lower SPL readings than before, especially as the SPL approaches 20 dBA and below, which is the territory of laptop drives. Our methodology focuses specifically on
noise, and great effort is taken to ensure it is comprehensively measured
and described. Performance is not tested comprehensively, for reasons discussed in detail in
the methodology article. In essence, between similar drives, we feel the performance differences are trivial, while the noise differences can be significant. Furthermore, many other hardware review sites (such as The Tech Report, Anandtech, and X-bit Labs) do a good job of covering the performance (speed) aspects of HDDs, while none of them do a thorough job of noise analysis.

A. ACOUSTICS

Two forms of hard drive noise are measured:

1. Airborne acoustics
   
2. Vibration-induced noise.

These two types of noise impact the subjective
perception of hard drive noise differently depending on how and where the drive
is mounted.

Both forms of noise are evaluated objectively and
subjectively. Airborne acoustics are measured in our anechoic chamber using a lab reference
caliber microphone and computer measurement system. Measurements are taken at a distance of one meter from the top
of the drive using an A-weighted filter. Vibration noise is rated on a scale
of 1-10 by comparing against our standard reference drives.

A final caveat: As with most reviews, our comments
are relevant to the samples we tested. Your sample may not be identical. There
are always some sample variances, and manufacturers also make changes without
telling everyone.

Ambient conditions at the time of testing were 11 dBA and 20°C.

NOTEBOOK DRIVE NOISE EVALUATION
Drive Mfg date firmware version	Vibration 1-10 (10 = no vibration)	Activity State	Airborne Acoustics	Measured Power
Seagate Momentus 5400.6 500GB ST9500325ASG Date: 12/02/2009 firmware 0001SDM1	8	Idle	16 dBA@1m	0.65 W (heads unloaded) 0.8 W (heads loaded)
		Seek (Normal)	18 dBA@1m	2.2W
WD Scorpio Blue 500GB WD5000BEVT Date: 08/08/2008 firmware 01.01A01	7	Idle	15 dBA@1m	0.8 W (heads unloaded) 0.95 W (heads loaded)
		Seek (Normal)	15 dBA@1m	2.5 W

The results of the acoustic and vibration tests were somewhat surprising. First, despite the Seagate’s apparently lower acoustic spec, the WD was actually quieter at idle — by just under 1 dBA@1m. Subjectively, this difference is insignificant. What’s more surprising is that the WD measured lower in airborne noise despite its much higher level of vibration. Our standard procedure of placing the tested drive on a soft foam pad helped keep the measured SPL of the WD low by isolating the vibration from being transferred to the workbench — the workbench top would have become an acoustic diaphragm for the drive.

The WD Scorpio’s vibration level was high enough for possible shipping damage to be suspected, but S.M.A.R.T analysis using WD’s own Lifeguard Diagnostics sofware indicated perfectly good health for all of the tracked criteria.

The frequency spectrum captures below shows that the WD measures 10 dB higher at the primary 90 Hz tone of the spin speed (5400RPM), which is indicative of the vibration difference between the drives. Also evident is a higher midband peak in the Seagate which is probably responsible for the slightly higher overall SPL.

In the WD, the difference in perceived noise between seek and idle was so small to be trivial under the test conditions. There was a touch more audible noise when listened at about 1′ distance, but the measured SPL increase was less than 1 dBA@1m on average. Hitachi Tool gave access to AAM on the WD; there’s no point enabling it because there is no perceptible difference between lowest acoustic and highest performance. The low noise position always increases the access time.

Seek noise in the Seagate was more marked. AAM is not supported on this drive, so HD Tach was used to engage seek. The chattering caused SPL to rise about 2 dBA@1m higher than at idle.

Both drives had very low power demand, with the Seagate a touch lower across the board. With both drives, the heads unloaded after less than ~10 seconds of inactivity, then power demand dropped another 0.1~0.2 W. The load figures of 2.2 W and 2.5W are peaks; average load power was probably at least 10% less.

B. PERFORMANCE

High transfer speed is expected with the high areal density of these drives, and both samples delivered the expected performance. There’s little to separate the two. It’s interesting to note that the ~70 MB/s read speed of these 5400RPM drive easily surpass the manufacturer’s specification of performance 59.0 MB/s for the 160GB 7200RPM Seagate Momentus reviewed a little over a year ago.

Seagate Momentus 5400.6 500GB: 66.9 MB/s avg read, 18.1ms random access. WD Scorpio Blue 500GB: 68.6 MB/s avg read, 16.9ms random access.

 

PRACTICAL NOTES

Considering their use in a notebook computer…

• At idle, which represents ~80% of typical usage, the Seagate would be quieter because of its lower vibration. The WD’s higher vibration would increase the residual noise of the system.
• During seek, the Seagate’s higher seek noise would be more plainly audible.
• Despite their high capacity, neither of these drives will consume any more power than a 80GB drive from several years back, and the performance boost (mostly in throughput) should be very noticeable.

In a desktop PC…

• The WD really would have to be soft-mounted for the user to benefit from its low air-borne noise.
• You’d want the Seagate soft-mounted to reduce the higher noise at seek.
• It’s easy to rig up an elastic cord suspension to hold any 2.5″ notebook drive in most 3.5″ HDD bays. But if you’d rather have a ready-made product, the NoiseMagic NoVibes 2.5 Silent Hard Drive Mounting System eliminates HDD vibration as well as any DIY solution.
• While random access speed is significantly slower than a typical 7200 RPM 3.5″ drive (12~14ms vs 17~18ms), the ~70 MB/s average read speed is not far off from the 80~90 MB/s typical of today’s 600~1,000 GB desktop drives.

COMPARED TO…

One problem we run into when trying to compare the acoustics of these drive with those of previously tested ones is that the latter did not have the benefit of our anechoic chamber and improved audio test equipment. They were measured in the same room, but before the treatments which eliminated the echoes in the room and lowered the noise floor. The drives tested in this review are quiet, but how exactly they stack up again the previously tested drives is difficult to say precisely.

The last complete comparison table of tested 2.5″ drives is on page 3 of the Seagate Momentus 160GB 7200RPM 2.5″ drive review. The lowest measured SPL of any drive on that table was 17 dBA@1m, for a Samsung 40GB MP0402H, which has been our quiet HDD champion since it first came to our attention. One of those drive samples happens to be with us still today, so we ran it through our new test procedures in the anechoic chamber.

NOTEBOOK DRIVE NOISE EVALUATION
Drive Mfg date firmware version	Vibration 1-10 (10 = no vibration)	Activity State	Airborne Acoustics	Measured Power
Seagate Momentus 5400.6 500GB ST9500325ASG Date: 12/02/2009 firmware 0001SDM1	8	Idle	16 dBA@1m	0.65 W (heads unloaded) 0.8 W (heads loaded)
		Seek (Normal)	18 dBA@1m	2.2W
WD Scorpio Blue 500GB WD5000BEVT Date: 08/08/2008 firmware 01.01A01	7	Idle	15 dBA@1m	0.8 W (heads unloaded) 0.95 W (heads loaded)
		Seek (Normal)	16 dBA@1m	2.5 W
Samsung 40GB MP0402H	8	Idle	13 dBA@1m	0.75 W
		Seek (Normal) Seek (AAM)	15 dBA@1m 13 dBA@1m	2.35 W

The little old Samsung retains its crown, being quieter by about 3 dBA@1m, and with AAM engaged, it’s just as quiet seeking as in idle. Will you be able to hear the increased loudness of the Seagate and WD 500 GB drives over the old Samsung? Maybe. In a laptop computer and quiet room, probably; but in a desktop, if you use soft mounting, probably not.

But drive technology has advanced; increased areal density alone has led to a big jump in read/write speed. The screen capture of HD Tach results for the Samsung tells the story. Few users would accept the 26.2 MB/s speed of the Samsung even if it is 3 dBA quieter; the WD and Seagate, with soft mounting, can be made quiet enough.

The 40 GB PATA Samsung random access keeps pace with the latest 500 GB drives under review here, but the read speed is nearly three times slower.

Another question that comes up is. “How much noise difference is there between these 2.5″ drives and standard desktop drives?” Here’s a quick comparison between them and the latest desktop drives tested (or retested) in the anechoic chamber.

REVIEWED 500 GB 2.5″ DRIVES
Drive Mfg date firmware version	Vibration 1-10 (10 = no vibration)	Activity State	Airborne Acoustics (dBA@1m)	Measured Power
Seagate Momentus 5400.6 500GB ST9500325ASG Date: 12/02/2009 firmware 0001SDM1	8	Idle	16	0.65 W (heads unloaded) 0.8 W (heads loaded)
		Seek (Normal)	18	2.2W
WD Scorpio Blue 500GB WD5000BEVT Date: 08/08/2008 firmware 01.01A01	7	Idle	15	0.8 W (heads unloaded) 0.95 W (heads loaded)
		Seek (Normal)	16	2.5 W
DESKTOP DRIVES
Seagate Pipeline HD Pro 1TB ST31000533CS September 2008 firmware SC15	4	Idle	15	7.1 W
		Seek	16	10.1 W
Western Digital WD1001FALS July 2008 firmware 05.00K05	4	Idle	21	8.5 W
		Seek (AAM)	21	10.9 W
		Seek (Normal)	25	11.0 W
WD VelociRaptor WD3000GLFS 300GB, 10K RPM 15 May 2008 firmware 03.03V01	8 [w/o frame]	Idle	15	8.2 W
		Seek (AAM)	20	12.2 W
		Seek (Normal)	22	12.2 W
Western Digital WD6400AAKS February 2008 firmware 01.03B01	7	Idle	16	6.8 W
		Seek (AAM)	16~17	8.1 W
		Seek (Normal)	18~19	9.3 W
Western Digital Raptor WD1500ADFD March 2006 firmware 20.07P20	5	Idle	16	8.2 W
		Seek (AAM)	26~27	12.2 W
		Seek (Normal)	26~27	12.2 W
Samsung F1 3D HD753LJ February 2008 firmware 1AA01109	6	Idle	16	6.9 W
		Seek (AAM)	18~19	8.9 W
		Seek (Normal)	20~21	10.2 W
WD Caviar SE16 500GB WD5000KS March 2006 firmware 07.02E07	4	Idle	19	8.5 W
		Seek (AAM)	19	8.6 W
		Seek (Normal)	22	10.7 W
* These drives are references in the sense of previously tested and known entitities to which newly tested products can be compared and contrasted against.

The usual advantages of 2.5″ drives over desktop drives are lower noise, lower vibration and lower power / heat. The laptop drives are still far more energy efficient, but these days, the difference in noise is starting to blur, especially if all the drives are softmounted. The quietest desktop drives are now quite close to the laptop drives. Their higher moving mass tends to increase the overall vibrational noise more than the smaller 2.5″ drives, so they still still benefit more from soft mounting.

AUDIO RECORDINGS

These recordings were made with a high resolution, lab quality, digital recording
system inside SPCR’s own 11
dBA ambient anechoic chamber, then converted to LAME 128kbps encoded MP3s.
We’ve listened long and hard to ensure there is no audible degradation from
the original WAV files to these MP3s. They represent a quick snapshot of what
we heard during the review.

These recordings are intended to give you an idea of how the product sounds
in actual use — one meter is a reasonable typical distance between a computer
or computer component and your ear. The recording contains stretches of ambient
noise that you can use to judge the relative loudness of the subject. Be aware
that very quiet subjects may not be audible — if we couldn’t hear it from
one meter, chances are we couldn’t record it either!

The recordings start with 8 seconds of silence, then 10 second segments
of the drive in the following states: idle, seek with AAM disabled. Ideally, you should set the volume of the playback during the “sound of silence”, then do not touch the volume control again throughout the listening.

• Seagate Momentus 5400.6 500GB ST9500325ASG — Idle: 16 / Seek: 18 dBA@1m— One
  Meter
• WD Scorpio Blue 500GB WD5000BEVT— Idle: 15 / Seek: 16 dBA@1m— One
  Meter

Recordings of Desktop Drives in the anechoic chamber:

• Seagate Pipeline HD Pro ST31000533CS — Idle: 15 / Seek: 16
  dBA@1m— One
  Meter
• WD Caviar Blue WD6400AAKS — Idle: 16 / Seek
  (AAM): 16~17 / Seek (Normal): 18~19 dBA@1m— One
  Meter
• Samsung F1 3D HD753LJ — Idle: 16 / Seek (AAM): 18~19
  / Seek (Normal): 20~21 dBA@1m— One
  Meter
• Seagate 7200.11 1.5TB ST31500341AS — Idle: 17 / Seek: 19
  dBA@1m— One
  Meter
• Seagate 7200.11 1TB ST31000340AS — Idle: 18 / Seek: 19 dBA@1m—
  One
  Meter
• Western Digital Caviar SE16 WD5000KS — Idle: 19 / Seek (AAM):
  19 / Seek (Normal): 22 dBA@1m— One
  Meter
• Western Digital Caviar Black WD1001FALS — Idle: 21 / Seek
  (AAM): 21 / Seek (Normal): 25 dBA@1m— One
  Meter
• Western Digital Raptor WD1500ADFD — Idle: 16 / Seek
  (AAM): 26~27 / Seek (Normal): 26~27 dBA@1m— One
  Meter

CONCLUSIONS

The WD Scorpio Blue and the Seagate Momentus 5400.6 500GB 5400RPM notebook drives both provide very good performance and capacity that would have been gi-normous even in a desktop drive a couple of years ago. The ~70 MB/s average read speed of these models makes them nearly as fast as today’s desktop drives in data transfers. Yet, they are miserly in their energy demand, asking less than 1W in idle and no more than 2.5W at any time.

We’ve usually associated high capacity and performance with higher noise. In these 500GB notebook drives, the acoustic level is quite low, nearly equal, but there are subtle differences. The WD has a bit more vibration, which will cause the case it’s mounted in to vibrate and increase its noise floor. The Seagate has much lower vibration but a bit more seek noise, and the contrast between that and idle will be more noticeable. It’s a toss-up as to which is the better choice for the noise conscious user.

For a desktop PC, either of these drives should be soft-mounted for best noise benefits. As a replacement notebook drive, the Seagate gets the nod; its noise will be less evident in idle, which is the dominant mode even for power users. (Owners of older laptops should ensure that their machine accepts the SATA interface of these drives.)

At the ~$100 asking price, the capacity and speed of these little drives is astonishing for anyone who recalls paying $300+ for a 40GB 3.5″ drive less than a decade ago. These are good times for HDD consumers.

Many thanks to Seagate
and to Western Digital for the respective drive samples.

* * *

POSTSCRIPT In early 2009, looming over these and every other spinning drive is the dramatically declining curve of the price of solid state drives. SSDs’ usability continues to improve, with performance besting the fastest of current disc drives. At time of writing, an excellent 128 GB Samsung based SSD is selling “on the street” for little over $300. For most laptop users, this capacity is perfectly adequate, and the relatively high price is balanced against the benefits of hugely improved shock resistance, zero noise and constant sub-1W power demand with attendent lack of heat. These are compelling factors that will transform the storage sector as price continues to fall and performance/reliability keeps improving. Spinning disk drives may soon be relegated to the task of mass data storage, while the SSD takes over the role of the OS drive.

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SPCR Articles of Related Interest:
SPCR’s Hard Drive Testing Methodology
SPCR’s Recommended Hard Drives
Seagate Momentus 7200.1 100 GB SATA Notebook
Drive
Seagate Momentus 5400.3 160 GB Notebook Drive
Hitachi E7K100 7.2k-RPM Notebook Drive

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Discuss this article in the SPCR Forums.