- WD Caviar Green hard drives reduce power consumption bу up tο 40%
- A fine-tuned balance οf spin speed, transfer rate аnԁ caching algorithms designed tο deliver both significant power savings
- IntelliSeek – Calculates optimum seek speeds tο lower power consumption, noise, аnԁ vibration.
- 2TB capacity holds up tο 400,000 digital photos, 500,000 MP3 files, аnԁ 240 hours οf HD video.
- Ships іn Certified Frustration-Free Packaging
List Price: $ 159.99
Price: $ 109.99
Western Digital 2 TB Caviar Green SATA Intellipower 64 MB Cache Bulk/OEM Desktop Hard Drive WD20EARS
WD Advanced Format technology increases media format efficiency, thus enabling Ɩаrɡеr drive capacities. WD Advanced Format drives аrе specifically optimized fοr Mac аnԁ thе latest Windows operating systems such аѕ Windows Vista аnԁ Windows 7. WD Advanced Format drives work wіth legacy operating systems such аѕ Windows XP bυt require thе υѕе οf thе free WD Align software available οn www.wdc.com/advformat. Available іn capacities up tο 2 TB, WD Caviar® Green™ SATA hard drives reduce power consumption bу up tο 40% аnԁ offer best-іn-class acoustics аnԁ operating temperature. Based οn WD’s exclusive GreenPower™ technology, thеѕе drives аrе designed tο deliver power savings аѕ thе primary attribute. Aѕ hard drive capacities increase, th
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For you EE propeller heads out there, here is some electrical data,
I have bought a LOT of the 2TB WD Caviar drives. I have had excellent results with them on my iMac. I use them primarily for data storage where fast data retrieval is not a consideration. I’m more concerned with plugging them into these USB-based drive docks when I need the data. However, I’m also interested in them from an electrical perspective, just because … well, just because I’m interested in them. Over the years I have worked my way up the ladder of hard drive storage capacities. Like many of you, I’ve been rather appalled at how hot these older models would get. I swear, you could fry an egg on some of them. I never felt comfortable with their longevity, fearing that they would most likely burn themselves up. Fortunately, none did.
When the Caviar Green product line came out (1TB was when I first took notice), I was quite intrigued at the claimed power reduction. In electronics, heat is the main enemy of components. Usually every 10 degree C rise in temperature translates into a halving of component life. The Caviar brand looked like a way to get a much more reliable drive if the power reduction numbers actually panned out.
I took one of the drives in to work where I have fancy test gear at my disposal. In particular, I have some very good Tektronix current probes that let me measure DC and AC currents. I built a little cable that let me get to the +12V and +5V lines so that I could clamp my current probes around the wires to measure current consumption. I connected the two power leads to power supplies so that I could also vary the two voltages. In this fashion, I can accurately see and measure power consumption of the drive as I exercise the drive. I get far more accurate measurements this way than you can with a simple watt-meter, which seldom let you see fractional watts.
Since I can’t (actually, don’t know how to) embed scope photos in this review, all I can do is verbally describe my observations. My tests are far from extensive, but they will give you a good idea of how much power these drives draw, and when they draw it.
* When the drive is just sitting there, doing nothing but spinning, the +12V current drain is 0.24A and the +5V drain is 0.13A. That totals 4.2 watts of power during idle. I have not measured earlier, high-power drives, but I’m willing to bet the Caviar Greens draw at most half the power of traditional hard drives. I would not be surprised if it were 1/3 the power.
* If you shut off one voltage, the other supply stops drawing all power. It’s a convenient way to power the drives on and off. I would suggest power cycling the +5V rail as the circuitry to shut off the +5V supply with a simple PFET is simpler than that for the +12V rail.
* When the drives are first powered up, +5V draws an almost constant 500-600 mA. +12V current is a ramp, starting at 200 mA and works its way up to 600 mA after about 10 seconds, when the drive is then up to speed. At this point, the +12V peak current drops down to idle spinning) current of 0.24A. It does not vary much after this, regardless of disk activity (erase, write, read, etc.). On the other hand, the +5V supply current gets busy. It’s pretty clear that the head servo is driven from the +5V supply and not the +12V supply. It’s hard to verbally describe the +5V current, but I would say the average current during head movement activity is about 400 mA. When there is no activity, the +5V current is about 0.13A. When the drive is done doing what it is doing, then it drops into the 4.2W idle power mode that I mentioned above. If you are a power supply designer, you should be aware that these DC currents I cite are averages, and that you have a “hash” of AC currents that result in the average values I list. The +5V current has a hash of about 300mA p-p, and the +12V current hash is maybe 400mA p-p.
* I have never succeeded in getting OSX to put the drives to sleep. I’ve tried all the utilities in the Mac universe (SpinDown, Cocktail), but no matter what you do, the drives never want to got to sleep, at least for me. If WD puts out a utility for the PC, they certainly offer no support for OSX. Even if you properly eject the drives from the desktop, they sit there spinning and drawing 4.2W. Hardly seems “fully green” to me.
* During the idle mode, my infrared thermometer measures a case temperature rise of 12 degrees C, which is a pretty low number. UL safety limits for human hand touch temperatures are usually between 50-55 degree C — you’ll begin to pull your hand back at that temperature range. So if the drive is 12 degrees above ambient, and you are sitting at normal room temperatures (25 degrees), then your drive temperature is only about 37 degrees (98.6 degrees F, just like a human!). This explains why people are reporting that the drive “feels pretty cool.” As these things go, they do indeed run quite cool…
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|Buy this drive,
I’ve bought six of these. They are quiet. After many hours, they are barely warm to the touch. Every other hard-disk drive made can be used as a space heater.
They are a bit slower, adding about 33% to the seek time, but nothing noticeable to data reads. This only matters when reading lots of small files like during boot-up. I use an Intel SSD for my main drive and one of these for data. It is the best of both worlds.
I’ve found that most computers recognize these drives but must be told to mount them, format them, and assign them a drive letter. (This only needs to be done once.) This is a problem with large drives, not with these specifically. For true ease of setup, get a 1TB drive.
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|Not worth the trouble; Returned my drives.,
I’m a software engineer and I have enormous archives of data. I currently have more than fifty drives on the shelf behind me, totaling about 20 terabytes of data.
For the last two years, I’ve used almost exclusively the Western Digital Green drives. Perhaps a half dozen each of the 750gb, 1tb, 1.5tb drives. They’ve been fantastic for data storage.
When the 2tb version reached the right price point, I ordered a couple of those. I was aware of the issues with sector size, detection, and formatting in Windows, but I use Solaris, Linux, and OSX almost exclusively. These drives were being used in OSX, which does have support for these drives.
However, when I plugged both drives in, I had a hell of a time formatting them through the Disk Utility and had to do it manually on the command line.
The real problems began after the drives were formatted and I had moved a ton of data to them. On one of the drives, I renamed a folder which contained about 1.25tb of data. Instantly, the folder disappeared and the drive appeared empty. That’s right. I renamed the folder all my data was in and that magically deleted all my content.
Upon closer inspection, the data was still there – it just didn’t appear in the file system. Thankfully, I was able to recover the data with some command-line-fu. I then reformatted the drive and gave it a torture test until the time I had to get these back in the box to return to Amazon before the refund period expired. I found boh of the drives to be questionable, but the one drive above to be particularly bad. It could have been just a bad drive or it could be a consistent problem across all of the 2tb WD Greens. My test sample (two drives) isn’t adequate to extrapolate.
I will say that the experience was enough to drive me away from the 2tb version. I’ve instead gone back to buying the 1.5tb WD Greens and replaced both 2tb drives with three of those.
I don’t believe the EARS vs EADS version has anything to do with it as I’ve been using the 1.5tb versions for a long time now and that includes both EARS and EADS drives. They have been stable and I have never had any issues with them.
I’ve had good experiences until recently with Western Digital’s drives, but I’m too gun-shy from the latest experience to try their 2tb drives again any time soon. Back to the trusty 1.5tbs.
Update: I wrote this review the first week of June and as of the second week of August, I have been running a few 2tb WD EARS drives exclusively in a pair of Drobos (as I mention in further replies to this review, the company behind Drobo sell exclusively WD green drives to meet thermal and power needs for their devices). I’ve had four 2tb WD EARS running in a single Drobo for more than a month now without any of the problems that I experienced on the other 2TB WD EARS that I used. I’m not sure if this is due to how the Drobo interfaces with and utilizes the drives (and compensates for the slow response times, perhaps?) or if there has been some improvement in newer productions of the drive, or if some of us just had a bad batch (the newest drives were purchased from another leading online tech retailer. Think chicken reproduction…).
At any rate, I am not sure I’ll trust these drives directly in a system or as attached storage other than part of a dedicated Drobo-type system. They may be fine for that use (as I’ve said before, I can only comment on my personal experiences and observed experiences of other people with this drive), but I’m not willing to risk it since we’re talking about large amounts of data.
My continued advice based on my latest experiences are that you should still consider these drives, but ONLY if you are aware of and willing ot accept the possibility that you may have to deal with returning/exchanging/replacing your drives. As always, Amazon treats customers very well when they have problems with products — so as long as you can take the time and effort to do that if you encounter severe drive issues with these, then perhaps the nice price on these will be worth it.
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