Western Digital’s Caviar Green 2TB hard drive

I have a theory that data expands to fill available capacity, much in the way work expands to fill available time, and Jessica Simpson expands to fill available magazine covers. If the capacity is there, we tend to use it. And why not? There’s no sense in letting gigabytes go to waste.

Our thirst for capacity largely drives the storage industry. Sure, enthusiasts crave performance; we’re constantly clamoring for faster seek times and higher sustained transfer rates. But most folks simply want more room to put more stuff. In recent years, most of that stuff has become digital media—pictures, music, and video, with the latter in increasingly gigabyte-gobbling high definition.

For most of the past year and a half, we’ve sated our appetite for capacity on a steady diet of terabyte hard drives. Hitachi was the first to reach the milestone with a 1TB Deskstar 7K1000 back in 2007. Last fall, Seagate raised the bar one notch higher with the 1.5TB Barracuda 7200.11. Now it’s Western Digital’s turn to claim the capacity crown with the Caviar Green 2TB.

This latest Caviar is of course interesting for its record capacity and the high areal density that enables it. The first 2TB drive is also a member of a GreenPower family renowned for energy efficiency and low noise levels, making it even more intriguing. Join us to find out if Western Digital has managed to squeeze 2TB into a drive that’s quiet, power-efficient, and potentially fast enough.

New platters for GreenPower
The Caviar Green 2TB may be Western Digital’s third-generation GreenPower drive, but the technology behind it is similar to existing members of the family. These drives feature IntelliSeek just-in-time drive head delivery, which reduces seek power consumption, noise levels, and even vibrations. They incorporate NoTouch ramp load tech inherited from WD’s Scorpio mobile line that completely moves the drive head off the disk when it’s not in use. On higher-capacity models like the new 2TB variant, a StableTrac motor also makes an appearance, securing the spindle shaft at both ends to keep the platters spinning true.

It’s on the platter front that the latest Caviar Green brings something new to the table. Western Digital stacks four platters inside the drive, and each weighs in at 500GB—50% more capacity per platter than the last Caviar Green’s 333GB discs.

While 500GB platters may be new to the Caviar Green, this isn’t the first drive to offer such a high areal density. Seagate has been selling single-platter Barracuda 7200.12 500GB drives for some time now, and those platters have already made their way into a 1TB model. However, the company’s 1.5TB Barracuda is based on 375GB platters, and it doesn’t expect to hit 2TB until the third quarter of this year.

Western Digital has taken a different approach to 500GB platter deployment, electing to launch them in a flagship capacity first. The new platters will migrate down to lower capacity points in the coming months, with 500GB and 1TB models due in March. A 1.5TB Caviar Green will follow, although WD hasn’t been more specific about when that drive will arrive.

When 500GB and 1TB takes on WD’s fresh platter tech do arrive, they might be difficult to spot in the wild. There wasn’t a problem when the Caviar Green 1TB jumped from 250 to 333GB platters because its model number changed from WD10EACS to WD10EADS. However, that’s because the D actually denotes a change in the drive’s cache size from 16 to 32MB. With 500GB platters, the 1TB Caviar Green will still be known as the WD10EADS, making it difficult to distinguish from the existing 333GB/platter model. Western Digital says that drives based on the new platters will quickly replace their predecessors in the marketplace, but there should really be an easy way for prospective customers to identify which version they’re buying.

Speaking of unnecessary obfuscation, Western Digital remains stubborn in its refusal to publish spindle speeds for its Caviar Green line. The company will only say that the spindle speeds for these drives sit between 5,400 and 7,200RPM, with rumor, speculation, and deduction pegging speeds closer to the former than the latter. Western Digital collectively refers to the Caviar Green line’s spindle speed as IntelliPower, which indicates that actual RPMs are set based on a collection of target characteristics including power consumption, noise levels, and performance. These spindle speeds are not consistent across the entire range of Caviar Greens, either; drives that use more platters tend to consume more power and generate more noise, so they likely run at slower speeds to compensate. But only slightly slower speeds—WD says that Caviar Green spindle speeds differ by no more than 5% across the line.

Having power consumption and noise levels play a part in determining the Caviar Green’s spindle speed makes perfect sense, and so does adjusting the RPMs to take into account the characteristics of different platter counts. After all, it’s not like Western Digital has stopped making performance-oriented drives at 7,200 and 10,000RPM. Failing to divulge spindle speeds under the guise of the GreenPower line not being a performance product is just silly, though. That’s like an automobile maker deciding not to publish horsepower or engine displacement numbers for a mini-van, arguing that it’s simply fast enough to get you to your destination in a reasonable amount of time.

What makes this situation even more puzzling is the fact that Western Digital does publish a sort of top speed specification, claiming that the Caviar Green 2TB’s maximum sustained data rate is 100MB/s. Oddly, though, that transfer rate is actually slower than the 111MB/s WD claims for the 333GB/platter Caviar Green 1TB. Even if the 2TB drive’s spindle speed is at worst 5% slower, it still has 50% more gigabytes per platter, which should yield significantly higher sustained transfer rates because so much more data is available under the drive head in a given track.

Of course, we’ve measured such things ourselves, and we’ll get to the results in a moment. The new Caviar Green’s power consumption and acoustic specifications are probably more relevant than its projected performance, anyway. WD claims the drive idles at just 25 decibels, consuming only four watts in the process, which is mighty impressive for a four-platter drive. Naturally, we have the results of our own power consumption and noise level tests to pore over.

This latest Caviar Green’s prodigious capacity adds a new wrinkle to the power consumption picture. It’s important to think of power consumption here not just as an absolute figure corresponding to the draw of one drive, but also as the wattage per gigabyte. The Caviar Green 2TB doesn’t need to be the most power-efficient hard drive around just as long as it consumes less power than other 2TB solutions, which today, require multiple drives.

Like other members of the Caviar Green family, this latest 2TB model is covered by a three-year warranty. Western Digital reserves five-year coverage for enterprise-class products and its premium Caviar Black line. Incidentally, WD is working on a RAID-optimized RE version of the 2TB Caviar Green, although there’s no word on when the drive is expected to hit the market.

Test notes
We’ll be comparing the performance of the Caviar Green 2TB with that of a slew of competitors, including some of the latest and greatest Serial ATA drives from Hitachi, Samsung, Seagate, and Western Digital. These drives differ when it comes to external transfer rates, spindle speeds, cache sizes, platter densities, and capacity, all of which can have an impact on performance. Keep in mind the following differences as we move through our benchmarks:

Note that we have three versions of Western Digital’s GreenPower desktop Caviar. The Caviar GP is the original GreenPower drive, model number WD10EACS, while the Caviar Green is the newer WD10EADS derivative with 333GB platters. The latest Caviar Green 2TB drive should be easy to spot because we’ve included its capacity in the graphs.

Performance data from such a daunting collection of drives can make our bar graphs a little hard to read, so we’ve colored the bars by manufacturer, with the Caviar Green 2TB appearing in brighter blue than the rest of Western Digital’s drives. Special thanks, a shout out, and mad props go to TR regular Usacomp2k3 for whipping up a slick VB script to automate graph coloring, saving me from entirely too much repetitive clicking.

The Caviar Green 2TB is both the highest-capacity drive on the market and a member of the energy-efficient GreenPower family, so you’ll want to pay attention to not only how it fares against the other GreenPower drives, but also Seagate’s Barracuda 7200.11 1.5TB.

Our testing methods
All tests were run three times, and their results were averaged, using the following test system.

Thanks to NCIX for getting us the Deskstar 7K1000 and SpinPoint F1.

Our test system was powered by an OCZ PowerStream power supply unit.

We used the following versions of our test applications:

• WorldBench 5.0
• Intel IOMeter v2004.07.30
• Xbit Labs File Copy Test v1.0 beta 13
• HD Tach v3.01
• Far Cry v1.3
• DOOM 3
• Intel iPEAK Storage Performance Toolkit 3.0

The test systems’ Windows desktop was set at 1280×1024 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled for all tests.

All the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.

WorldBench
WorldBench uses scripting to step through a series of tasks in common Windows applications. It then produces an overall score. WorldBench also spits out individual results for its component application tests, allowing us to compare performance in each. We’ll look at the overall score, and then we’ll show individual application results.

With only four points separating the fastest drive from the slowest in WorldBench, the Caviar Green 2TB doesn’t really set itself apart from the rest of the field. The latest GreenPower offering has an identical overall score to the last two members of WD’s eco-friendly line, putting it one point behind the 1.5TB Barracuda.

Multimedia editing and encoding

MusicMatch Jukebox

Windows Media Encoder

Adobe Premiere

VideoWave Movie Creator

It’s hard to get worked up about differences of just a few seconds in tests that take several minutes to complete. Among WorldBench’s multimedia editing and encoding tests, we really only see the field spread in Premiere, where the 2TB Green sits comfortably in the middle of the pack.

Image processing

Adobe Photoshop

ACDSee PowerPack

ACDSee is another member of the WorldBench suite that tends to prefer faster drives. In that test, the Caviar Green 2TB is actually a little slower than its 333GB/platter predecessor.

Multitasking and office applications

Microsoft Office

Mozilla

Mozilla and Windows Media Encoder

Nothing to see here. Move along.

Other applications

WinZip

Nero

WorldBench’s Nero and WinZip tests are its most demanding of the storage subsystem. In the former, the 2TB Green sticks to the middle of the pack and trails the 1.5TB ‘cuda by just one second. However, Nero turns the tables a little, with the Green trailing its Barracuda rival by a good 13 seconds. Both drives are still middle-of-the-pack performers, though.

Boot and load times
To test system boot and game level load times, we busted out our trusty stopwatch.

The 2TB Caviar Green’s boot time isn’t particularly impressive. It’s nearly the slowest drive of the lot here, although only two seconds behind the terabyte Green and 1.5TB ‘cuda.

While the 2TB Green claws its way out of the back of the pack in our game level load tests, it still lags behind the 1.5TB Barracuda.

File Copy Test
File Copy Test is a pseudo-real-world benchmark that times how long it takes to create, read, and copy files in various test patterns. File copying is tested twice: once with the source and target on the same partition, and once with the target on a separate partition. Scores are presented in MB/s.

To make things easier to read, we’ve separated our FC-Test results into individual graphs for each test pattern. We’ll tackle file creation performance first.

Even with a relatively slow spindle speed, the Caviar Green 2TB’s high areal density allows the drive to deliver competitive transfer rates in this batch of file creation tests. The 2TB Green is consistently faster than not only both of its predecessors, but also a number of 7,200-RPM drives, including the 1.5TB Barracuda.

Switching gears to read performance, the 2TB Caviar Green takes a beating from the 1.5TB Barracuda. The 2TB Green still sits in the middle of the pack, where it’s at least ahead of the other GreenPower drives.

FC-Test – continued

FC-Test’s copy tests stress both read and write performance, and the 2TB Caviar Green is better-equipped to handle that combination than the high-capacity ‘cuda. As expected, the latest Caviar Green continues to be faster than the GreenPower drives that came before it.

These partition copy tests are similar to FC-Test’s first wave of copy tests, except this time, data is copied from one partition to another. That difference doesn’t change the standings, with the 2TB Caviar Green still offering higher transfer rates than Seagate’s biggest Barracuda and other members of the GreenPower family.

iPEAK multitasking
We’ve developed a series of disk-intensive multitasking tests to highlight the impact of seek times and command queuing on hard drive performance. You can get the low-down on these iPEAK-based tests here. The mean service time of each drive is reported in milliseconds, with lower values representing better performance.

While the Caviar Green 2TB is largely quicker than its GreenPower kin in our iPEAK multitasking tests, it can’t catch the 1.5TB Barracuda. If you average the mean service time across all nine workloads, the 2TB Green scores 1.61 milliseconds while the ‘cuda works out to 1.21. Of course, the 333GB/platter Caviar Green 1TB scores a 1.99, so the new model’s denser platters certainly help to improve performance here.

IOMeter
IOMeter presents a good test case for both seek times and command queuing.

Western Digital’s latest Caviar Green may have been able to outrun its predecessors in most of our tests, but IOMeter presents a unique multi-user challenge, and it’s one that flummoxes the 2TB drive. The 2TB Green’s transaction rates are lower than those of both preceding GreenPower Caviars across all four test patterns. Interestingly, though, the 2TB Caviar runs largely neck-and-neck with the 1.5TB Barracuda, which only pulls ahead with the read-dominated web server test pattern.

CPU utilization is low for all our drives in IOMeter.

HD Tach
We tested HD Tach with the benchmark’s full variable zone size setting.

HD Tach’s straight-line sustained transfer rate tests expose the Caviar Green’s slower spindle speed, pushing it well behind the 1.5TB Barracuda and most of the 7,200-RPM field. The gaps between the 250GB/platter Caviar GP, the 333GB/platter Caviar Green 1TB, and the latest 2TB model are particularly interesting. Moving from the four-platter Caviar GP to the three-platter Caviar Green represents a 33% jump in per-platter capacity and about a 30% increase in sustained throughput. However, the jump from the three-platter Caviar Green 1TB to the four-platter 2TB model represents a 50% increase in per-platter capacity but not even a 4% improvement in sustained transfer rate.

Burst speeds are independent of platter counts and densities, so it’s no surprise to see the 2TB Caviar Green near the front of the pack here.

However, a slower spindle speed does tank the drive’s random access time, which is among the slowest of the lot, and roughly equivalent to that of the 1.5TB Barracuda. Both four-platter GreenPower drives have relatively high random access times, but the three-platter Caviar Green is a good millisecond or more quicker.

HD Tach’s margin of error in the CPU utilization test is +/- 2%, which neatly covers the range of drives we’re looking at today.

Noise levels
Noise levels were measured with an Extech 407727 Digital Sound Level meter 1″ from the side of the drives at idle and under an HD Tach seek load. Drives were run with the PCB facing up.

Although it’s a little louder than previous GreenPower drives under a seek load, the 2TB Caviar Green is as quiet as any other desktop drive we’ve tested at idle. What’s more, its seek noise levels are two decibels quieter than the 1.5TB Barracuda, which is a noticeable margin.

Power consumption
For our power consumption tests, we measured the voltage drop across a 0.1-ohm resistor placed in line with the 5V and 12V lines connected to each drive. We were able to calculate the power draw from each voltage rail and add them together for the total power draw of the drive.

Perhaps even more impressive than the Caviar Green’s low noise levels is the drive’s frugal power consumption. The 2TB Green actually consumes less power than the original Caviar GP at idle, and about the same under load. Sure, the 1TB Caviar Green pulls fewer watts, but it’s only spinning three platters and half the capacity. If you factor in the new Green’s whopping 2TB of storage, the drive delivers by far the lowest power consumption per gigabyte at both idle and under load.

Conclusions
Western Digital has captured the capacity crown by a comfortable margin with the Caviar Green 2TB, and it’ll likely hold onto the title for a while. That’s probably why the drive’s suggested retail price is a lofty $299—there’s a premium to be paid for flagship capacities, especially when the competition may be slow to catch up. MSRPs don’t always line up with street prices, though, and already at least one retailer has the 2TB Green listed for $270. At that price, you’re looking at over $0.13 per gigabyte, which is more than not only the $0.10 per gigabyte you’ll pay for a terabyte Caviar Green, but also the $0.09 per gigabyte offered by Seagate’s 1.5TB Barracuda.

So the latest Caviar Green isn’t a cost-per-gigabyte king. However, it’s often faster than the 1.5TB ‘cuda, which is its only competition above the terabyte mark. The latest Caviar Green is almost universally faster than its terabyte predecessor, as well, with the only real exception arising in IOMeter. Enterprise customers looking forward to an RE version of the 2TB Green won’t be impressed by the drive’s anemic performance under multi-user loads, but that matters not for the average desktop, home theater PC, or closet file server. For those applications, the 2TB Caviar Green is most certainly fast enough.

Of course, the Caviar Green isn’t a performance product. The drive’s acoustic and power consumption characteristics are far more important, and it does well on both fronts. Not only is the 2TB Green one of the quietest drives we’ve ever tested, it’s also among the most energy efficient. In fact, the new Green has the lowest power draw per gigabyte of any high-capacity desktop drive.

If you’re looking for conspicuous capacity in a surprisingly inconspicuous package, you’d be well-served to consider the Caviar Green 2TB. The drive is a perfect candidate for secondary storage in a high-performance PC, or even as the primary drive in systems that prioritize noise levels, power consumption, and capacity over blistering throughput and speedy access times. With Western Digital’s new 500GB platters set to quickly trickle down to more affordable price points, the Caviar Green’s future looks very bright indeed.