fzabkar, those graphs do not show RPMs but only transfer speed, so it is only assumption that RPM is 5900 which unfortunately doesn't prove anything

It would be interesting to measure real RPM, physically, or at least through Victoria (it has some clever ways to do it)

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SAN, NAS, RAID, Server, and HDD Data Recovery.

I have made no assumptions.

Those results don't show the RPMs directly, but if you follow my WD forum links, I have explained in detail how to determine the spin speeds from the access time graphs.

An interesting drive

WD5000AAVS
Real physical RPM = 5000
The spec sheet says "RPM IntelliPower"

From Amazon

"WD Caviar Green WD5000AAVS - Hard drive - 500 GB - internal - 3.5" - SATA-300 - 7200 rpm - buffer: 8 MB"

I wonder how hard I need to push it for RPM to increase :O)

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All went well until I plugged the drive in.

Well you are assuming again
Because you don't know why the rate is low
You are assuming that the only speed factor is RPM but there are possibly some others
1. FW of HDD can make rate lower because of marketing reasons
2. SATA spectrum or SATA mode can influence the rate
3. Hardware quality
3. SATA controller may not work properly with some drives
4. Density of platters

As at seems the RPM and density are the major factors but you cannot move something from "assumptions bucket" to "facts bucket" until you sure
And you cannot be in this case

_________________
SAN, NAS, RAID, Server, and HDD Data Recovery.

If you push enough you damage the cover

I don't understand the difficulty.

The label says that the drive is an RE4. WD's product specs say that RE4 drives spin at 7200 RPM, not Intellipower. HD Tune proves that that the drive is actually spinning a 5900 RPM. Therefore the drive is not really an RE4 model, but some other 5900 RPM model. Also, the firmware version reported by the drive, 01.00A01, appears to be associated with green Caviar models and Scorpio Blues, but not RE4 drives.

Here is an interesting claim:

Western Digital WD5000AAVS 500GB 5400 to 7200 RPM 16MB Cache SATA 3.0Gb/s 3.5" Hard Drive:
http://www.newegg.com/Product/Product.a ... 6822136230

RPM: 5400 to 7200 RPM

That said, I am aware that WDC uses "IntelliPower". Unfortunately WD's public information on the technology is no better than marketing-speak:

http://www.wdc.com/en/products/greenpow ... nology.asp

"For each drive model, WD may use a different, invariable RPM."

BTW, are there any drives that can operate at two different spin speeds?

AIUI, a drive's heads fly on an air bearing generated by the spinning platters. If the rotation speed were to vary, then so would the flying height, leading to variations in read/write amplitude. Therefore the heads are aerodynamically tuned to a particular speed, and that speed is tightly controlled. I expect that Thermal Flying Height Control (TFC) could compensate for minor changes, but it wouldn't make sense to use it for wide speed variations. Maybe Intellipower utilises moving aerodynamic devices. :-)

BTW, I am aware that there are drives which spin at lower speeds during power saving modes, but the heads are parked on a loading ramp during such times. See the following white paper.

Power and Acoustic Management:
http://www.hitachigst.com/tech/techlib. ... 5March.pdf

Here are more HD Tune results which show how RPM affects access time:

WD15EARS-00Z5B1 - 5400 RPM ?
http://sylphys.ddo.jp/upld2nd/pc3/src/1267687303631.png

WD15EADS-00P8B0 - 5400 RPM ?
http://ettcweb0.aa0.netvolante.jp/log/20090830004.png

ST32000542AS Barracuda LP - 5900 RPM:
http://users.telenet.be/Mastakilla/HDs/ ... write2.JPG

WD2001FASS-00U0B0 - 7200 RPM:
http://dl6.getuploader.com/g/6%7Cnews23 ... 4kB%5D.png

WD5001AALS-00L3B - 7200 RPM:
http://bbsimg01.kakaku.com/images/bbs/0 ... 6059_m.jpg

WD1500HLFS-01G6U0 - 10K RPM:
http://dl7.getuploader.com/g/6%7Cnews23 ... 01G6U0.png

ST3600057SS - 15K RPM:
http://images.kbench.com:8080/kbench/ar ... 31p1n6.jpg

The problem with changing drive serial numbers, is that it can be used for MASSIVE fraud.
I have seen examples of this in China.

There used to be an 'issue' with the Seagate website, for looking up serial numbers, now they have a 'person' detector.
I went to one shop in china In Guang Zhou where they had linked a barcode scanner to the seagate website.
they were using it to :
1. Get the money back that seagate offered for "oversizing" the drives. (you would take in a computer with a "real" seagate, they would jack it and put a refurbished part in, but flashed with new serials and bigger drive space)
2. Using it to 'jack' unused/ un expired serial numbers to print labels & flash the serial into refurbished drives.

I have also seen other frauds with other manufacturers, usually implemented by flashing a serial (some centers allow a walk in replacement service ) I.E you take a shite dead drive, replace the labels , re flash serial, get a refurbished drive back you can sell.

_________________
Universal Declaration of Human Rights: Article 19

Some easy to read specs

10,000 RPM SATA
600GB WD6000HLHX-01JJPV0 32MB SATA 6.0Gb/sec 3 Platters 6 Heads
600GB WD6000BLHX-01V7BV0 32MB SATA 6.0Gb/sec 3 Platters 6 Heads
450GB WD4500HLHX-01JJPV0 32MB SATA 6.0Gb/sec 3 Platters 5 Heads
450GB WD4500BLHX-01V7BV0 32MB SATA 6.0Gb/sec 3 Platters 5 Heads
300GB WD3000HLFS-01G6U3 16MB SATA 3.0Gb/sec 2 Platters 4 Heads
300GB WD3000BLFS-01YBU3 16MB SATA 3.0Gb/sec 2 Platters 4 Heads
150GB WD1500HLFS-01G6U3 16MB SATA 3.0Gb/sec 1 Platter 2 Heads
150GB WD1500BLFS-01YBU3 16MB SATA 3.0Gb/sec 1 Platter 2 Heads

3.5 SATA
2TB WD2003FYYS-02W0B0 64MB SATA 3.0Gb/sec 4 Platters 8 Heads
2TB WD2003FYYS-01T8B0 64MB SATA 3.0Gb/sec 4 Platters 8 Heads
2TB WD2002FYPS-02W3B0 64MB SATA 3.0Gb/sec 4 Platters 8 Heads
2TB WD2002FYPS-01U1B0 64MB SATA 3.0Gb/sec 4 Platters 8 Heads
1TB WD1003FBYX-01Y7B0 64MB SATA 6.0Gb/sec 2 Platters 4 Heads
1TB WD1002FBYS-02A6B0 32MB SATA 3.0Gb/sec 3 Platters 6 Heads
750GB WD7502ABYS-02A6B0 32MB SATA 3.0Gb/sec 3 Platters 5 Heads
500GB WD5003ABYX-01WERA0 64MB SATA 6.0Gb/sec 1 Platter 2 Heads
500GB WD5002ABYS-02B1B0 16MB SATA 3.0Gb/sec 2 Platters 4 Heads
320GB WD3202ABYS-02B7A0 16MB SATA 3.0Gb/sec 1 Platter 2 Heads
250GB WD2503ABYX-01WERA0 64MB SATA 6.0Gb/sec 1 Platter 1 Head
250GB WD2502ABYS-02B7A0 16MB SATA 3.0Gb/sec 1 Platter 2 Heads
3.5 SAS
2TB WD2000FYYG-01A21V0 64MB SAS 6.0Gb/sec 4 Platters 8 Heads
1TB WD1000FYYG-01A21V0 64MB SAS 6.0Gb/sec 2 Platters 4 Heads

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All went well until I plugged the drive in.

Exactly. That's it. The boundaries between "legitimate use" and "fraud" are very thin.