Logo   Banner   TopRight
WD Caviar Green 3TB Hard Drive Review
Date: Oct 19, 2010
Author: Mathew Miranda

While solid state drives get faster, mechanical hard drives get larger. Not long ago, we celebrated the first 1TB hard drive, and since then, welcomed 1.5TB and eventually 2TB drives to the consumer market. Yes, the performance increase that SSD's offer is more than impressive. However, they still can't touch the capacity that traditional hard drives provide tech-savvy, budget conscious consumers and system builders. When it comes to cost per gigabyte analysis, hard drives possess a huge advantage over SSD's.

Western Digital Caviar Green 3TB Hard Drive

Today, Western Digital announces the world's highest density hard drive, as they reach the 3TB mark with their newest, 5th generation Caviar Green product. To go along with its massive storage capacity, the Caviar Green 3TB serves up a super-sized combination of reduced power consumption, lower operating temperature, and a quieter working environment. Read on to find out how well it performs and if it deserves to be on your upgrade list.

Western Digital Caviar Green 3TB
Specifications and Features

SATA 3.0Gb/s
Capacity 3TB
Average Seek Time
Average Latency
Form Factor
3.5" (4 Platter Design, 750GB/Platter)
3 Years Limited

While the specs are straightforward, there are a couple of points worth mentioning. First, Western Digital is announcing two Caviar Green drives today. Along with the 3TB drive we're reviewing, there's also a 2.5TB model with the model number WD25EZRSDTL, selling for $189. Besides capacity though, the two drives are identical. Second, it's worth noting the Caviar Green 3TB drive makes use of the older SATA 3Gb/s interface, versus the newer SATA 6GB/s. But you won't hear us complaining about this omission, mainly because we've seen that traditional spinning HDD's still fall short of saturating the previous generation 3Gbps SATA interface. Next, let's dig a bit deeper into how Western Digital achieved the 3TB mark.

Breaking the 2.19TB Barrier

Unfortunately, if you're still using Windows XP, don't expect your system to make full use of any 3TB drive (yet). The problem is that older operating system, in combination with a legacy BIOS and master boot record (MBR) partition table scheme face a barrier at 2.19TB. Why? It's because they can only address up to 2^32 logical blocks, multiplied by sector size capacity. Since the most commonly used sector size is 512 bytes, mathematics tells us there is a capacity limit of 2,199,023,255,522 bytes or 2.19TB.

Advances in technology make the use of large capacity drives possible. One way would be to use a larger sector size, while keeping the number of addressable blocks the same. For example, using 4096 (4k) byte sectors would allow for systems to address a maximum of 2^32 x 4096 bytes, or 17.59TB. Unfortunately, there are too many application incompatibility issues when you go over 512 bytes.

Western Digital has made the transition to physical sector sizes of 4096 bytes and calls it Advanced Format (AF) technology. To address the problem associated by making this move, the hard drive reports and emulates a disk using 512 bytes.

Another solution is to utilize GUID partition tables (GPT) instead of master boot record (MBR) tables. While MBR restricts a disk's partition size to 2.19TB, GPT allows for a maximum size of 9.4 zettabytes. GPT forms part of the extensible firmware interface (EFI) standard and is Intel's proposed replacement for the BIOS.

Hopefully you like acronyms because we're going to throw some more your way. The EFI specification is governed by the Unified EFI forum. UEFI defines a new way for operating systems to work with system platform firmware. It's a community effort by a group of companies within the industry to bring the legacy booting process up to date. It's unlikely the motherboard in your system today supports UEFI, but according to Western Digital, most systems shipping now through Q2 2011 will be UEFI capable. 

Existing motherboards utilizing BIOS (non-UEFI), GPT ready operating systems like Windows 7 64-bit, and appropriate storage class drivers can use hard drives larger than 2.19TB as storage. A problem is a number of host bus adapter (HBA) and chipset vendors don't offer driver support for these types of drives.

To provide a solution for this compatibility issue, Western Digital bundles an HBA with the Caviar Green 3TB drive that allows the operating system to use a known driver to correctly support extra large capacity drives. Granted, this bundle is a short term solution until updated storage drivers and system software support become available industry wide. 

Early adopters should not disregard the bundled HBA. If you decide to add the Caviar Green 3TB as a secondary drive to your existing system that incorporates, for example, an Intel chipset on a non-UEFI mobo, the third party storage driver may not properly support it. If the drive is directly attached to the board's SATA port, the storage driver will probably not recognize its full capacity. In addition, any attempt to uninstall the driver could render the system inoperable. Bottom line is to make sure you use the bundled HBA for now. 

As with every hard drive, you can use the Caviar Green 3TB as a primary boot drive, or a secondary storage option. Just know that booting a current Windows operating system from any drive larger than 2.19TB requires a UEFI capable motherboard and a 64-bit version of the OS. We've only been able to verify a handful of consumer boards that support UEFI (several Intel models and one from MSI), so think of this drive as a secondary storage solution as of right now. 

Test System and ATTO

Our Test MethodologiesUnder each test condition, the drives tested here were installed as secondary volumes in our testbed, with a different hard disk used for the OS and benchmark installations.  The drives were left blank without partitions wherever possible, unless a test required them to be partitioned and formatted, as was the case with our ATTO and Vantage benchmark tests. Windows firewall, automatic updates and screen savers were all disabled before testing. In all test runs, we rebooted the system and waited several minutes for drive activity to settle before invoking a test.

HotHardware Test System
Intel Core i7 Powered

Processor -

Motherboard -

Video Card -

Memory -

Hard Drives -


Hardware Used:
Intel Core i7 870

Gigabyte P55A-UD7

GeForce GTX 280

4GB Kingston DDR3-1333

WD Caviar Green 3TB
Seagate Barracuda XT
Seagate Barracuda 7200.11
WD Raptor 160GB (OS drive)


Chipset Drivers -

Video Drivers

Relevant Software:
Windows 7 64-bit


NVIDIA ForceWare v260.89

Benchmarks Used:
HD Tach
ATTO ver 2.02
PCMark Vantage 64-bit
SiSoftware Sandra 2010

ATTO Disk Benchmark - Read/Write Performance
Version 2.41

ATTO is a more straight-forward type of disk benchmark that measures transfers across a specific volume length.  It measures raw transfer rates for both reads and writes and graphs them out in an easily interpreted chart.  We chose .5kb through 8192kb transfer sizes over a total max volume length of 256MB.  This test was performed on blank, formatted drives with NTFS partitions.

Western Digital Caviar Green 3TB

Seagate Barracuda XT 3Gb/s

Western Digital RE4

Seagate Barracuda 7200.11

Right from the start, the Caviar Green 3TB did well with very small transfer sizes. Unfortunately, that advantage quickly disappeared once we get over 8kb files. By the end of the benchmark, the drive recorded 139MB/s read and 106MB/s write speeds.

SiSoft SANDRA 2010

Testing began with SiSoftware's SANDRA XII, the System ANalyzer, Diagnostic and Reporting Assistant. Here, we used the Physical Disk test suite and provided the results from our comparison drives. The benchmarks were run without formatting and read performance metrics are detailed below. We also included SANDRA's graph so you are able to see how the drive performs over time along with the average rated result.

 SiSoft SANDRA 2010
 Synthetic Benchmark

Western Digital Caviar Green 3TB

Seagate Barracuda XT 3Gb/s

Western Digital RE4

Seagate Barracuda 7200.11

The Western Digital Caviar Green 3TB hit 100MB/s read performance. It was about 10% slower than Seagate's Barracuda XT and WD RE4, but was on par with the older Barracuda 7200.11.

Western Digital Caviar Green 3TB


Seagate Barracuda XT 3Gb/s


Western Digital RE4

Seagate Barracuda 7200.11

With write performance at 76MB/s, the Caviar Green trailed the other drives we tested by a wide margin. On average, it was 45% slower in this benchmark. 

CrystalDiskMark Testing

CrystalDiskMark is a synthetic test that evaluates both sequential as well as random small and large file transfers.  It does a nice job of providing a quick look at best and worst case scenarios with regard to hard drive performance, best case being large sequential transfers and worse case being small, random 4K transfers. 

CrystalDiskMark Benchmarks
Synthetic File Transfer Tests

Western Digital Caviar Green 3TB


Seagate Barracuda XT 3Gb/s


Western Digital RE4

Seagate Barracuda 7200.11

The Caviar Green 3TB offers competitive read speeds at 149MB/s, especially considering it was second only to the RE4 in this area. But as we saw with SANDRA testing, its write speeds are slowest of the group. Still, we were pleasantly surprised by its CrystalDiskMark performance numbers overall.

HDTach Benchmark

Simpli Software's HD Tach is described on the company's web site as such: "HD Tach is a low level hardware benchmark for random access read/write storage devices such as hard drives, removable drives, flash devices, and RAID arrays. HD Tach uses custom device drivers and other low level Windows interfaces to bypass as many layers of software as possible and get as close to the physical performance of the device being tested."

HD Tach v3

Western Digital Caviar Green 3TB


Seagate Barracuda XT 3Gb/s


Western Digital RE4

Seagate Barracuda 7200.11

Our HDTach results confirm the previous benchmarks we've run. With an average read speed of 111MB/s, the Caviar Green 3TB was able to keep up with the rest of the comparison group. In comparison, the Barracuda XT was only 5% faster. Unfortunately, read performance remains a weak point, reaching only 31MB/s.

PCMark Vantage

Next we ran the four drives through a battery of tests in PCMark Vantage from Futuremark Corp. We specifically used only the HDD Test module of this benchmark suite to evaluate all of the drives we tested. Feel free to consult Futuremark's white paper on PCMark Vantage for an understanding of what each test component entails and how it calculates its measurements. For specific information on how the HDD Test module arrives at its performance measurements, we'd encourage you to read pages 35 and 36 of the white paper.

Futuremark's PCMark Vantage

We really like PCMark Vantage's HDD Performance for its real-world application measurement approach to testing.  From simple Windows Vista start-up performance to data streaming from a disk drive in a game engine and video editing with Windows Movie Maker, we feel confident that these tests best illustrate the real performance profile of our hard drives in an end user/consumer PC usage model.

Although it turned in the slowest scores in almost every test, the Caviar Green 3TB was not that far behind. It was almost on par with the Seagate Barracuda 7200.11 drive and about 25% behind the Barracuda XT. 

PCMark Vantage Continued

Our next series of Vantage tests will stress the write performance. Applications like video editing, streaming and recording command a high mix of random write transactions. 

Futuremark's PCMark Vantage

None of the drives did particularly well in our Media Player or Application Loading tests. But the Caviar Green drive fell behind in comparison to the others, specifically during Windows Media Center and Movie Maker tests. On average, it was 25% slower than the Barracuda 7200.11, its closest competitor.

Performance Summary and Conclusion

Performance Summary: Although the Caviar Green 3TB drive was not designed for high end performance, we felt it necessary to run these benchmarks to find out how it stacks up in comparison to the other options available on the market. In general, the Caviar Green drive produced the slowest speeds out of all the high capacity drives we tested, but that was expected considering its competition. Keep in mind that the Barracuda XT and RE4 represent two of the fastest mechanical drives on the market. On a positive note, we found the drive turned in surprisingly competitive read speeds throughout testing. It even hit 149MB/s during the Crystal Disk Mark test. However, write speeds were relatively slow in comparison. The Caviar Green drive only reached a speed of 76MB/s, averaged across four different write tests

Let's consider price for a moment. At $239, the 3TB Caviar Green steps into a market loaded with competition. While there are no other individual 3TB drives to compete with (Seagate uses 3TB drives in their new BlackArmor NAS), there are plenty of options for those looking to upgrade their storage solution.  Within Western Digital's own lineup, we found a speedy 1.5TB RE4 at the same price point. Coincidentally, a 2TB RE4 could be had for an additional $10. Furthermore, the 2TB Caviar Green sells for $100 less than the 3TB version, at $139. Seagate drives also provide money saving options for consumers. The 2TB Barracuda XT drive we used in this article for comparison results goes for $199, while their "green" drive, the 2TB Barracuda LP, retails for $99. We also found Samsung EcoGreen and Hitachi Deskstar drives can be had for $129 in 2TB capacities.

The Caviar Green is definitely not the most affordable hard drive available. But a quick glance at the cost per gigabyte graph above illustrates its overall value. Western Digital didn't charge a premium to the cost of the drive, as it lands between the 2TB Caviar Black and the 2TB Caviar Green in terms of cost/GB, right where we would expect to be.

More is better - this old maxim definitely applies to data storage capacity. And now that we've hit 3TB, another milestone has been reached while providing a strong argument for hard drives in the HDD vs SSD debate. With the Caviar Green 3TB, we found a drive with solid read performance to go along with it a staggering amount of storage capacity. Granted, the need for an additional host bus adapter is a small inconvenience for early adopters to ensure compatibility for all users. Of course it's not ideal, but it's a temporary solution while the rest of the industry can catch up to the point where UEFI capable motherboards become the standard. Until then, if you're in the market for the maximum amount storage capacity available, you might want to check out the colossal Caviar Green 3TB hard drive from Western Digital. 


  • Massive Capacity
  • Good Value
  • Decent Read Performance
  • 64MB Cache
  • Bootable only when used with UEFI capable mobo
  • Requires additional Host Bus Adapter
  • Relatively slow Write Speeds

Content Property of HotHardware.com