Two months ago I looked at the world’s first 3TB desktop hard drive. It was a 5 platter, 3TB Seagate Barracuda XT inside an external GoFlex Desk chassis. The performance of the drive wasn’t anything out of the ordinary, but the poorly ventilated chassis seemed ill equipped to deal with the thermal load a 5-platter, 7200RPM 3TB drive would throw at it. I wasn’t terribly pleased and I wondered if Western Digital’s external enclosure might be better suited for heat dissipation. WD’s 3.5” external drives fall under the My Book brand and they have visibly more ventilation than the GoFlex Desk I reviewed.

As luck would have it, last week Western Digital announced its own 3TB external drive: the My Book Essential. The Essential suffix somehow implies USB 3.0 support.

Today, Western Digital takes it one step further and announces availability of the internal drive as well. The Caviar Green line is now home to a 2.5TB and a 3.0TB model, priced at $189 and $239 respectively.

Let’s go ahead and review both shall we?

The Caviar Green 3TB

Seagate’s external 3TB offering used five 600GB platters to hit the magic capacity point. While increasing platter count is a quick way to get a larger drive, increasing areal density is the desired approach. Seagate’s quick time to market justified the former, while Western Digital’s desire to deliver a low power drive demanded the latter.

As a result the Caviar Green 3TB uses only four 750GB platters, giving this drive the highest platter density of any 3.5” hard drive.

Western Digital Caviar Green 3TB
Interface SATA 3Gbps
Formatted Capacity (Base 10) 3,000,592 MB
User sectors per drive 5,860,533,168
Cache Size 64MB
Load/unload cycles 300,000
Limited Warranty 3 years

Spindle speed is another differentiating factor between WD’s drive and the earlier Seagate offering. While the GoFlex Desk houses a 7200RPM hard drive, WD’s 3TB drive is sold under the Green label. Western Digital doesn’t disclose actual spindle speed as it isn’t consistent across all Green label drives. The 3TB specs simply list it as IntelliPower.

I asked WD for more specifics and I got a reasonable explanation. In the Green line WD optimizes for power consumption. It attempts to make all drives consume roughly the same amount of max power, which happens to be 3 - 5W below a typical 7200RPM drive. The spindle speed isn’t dynamic, it’s set at manufacturing and remains at that.

All green drives will spin below 6000 RPM and the spec never drops below 5400RPM. What this means is that all 2.5TB drives will spin at one speed while all 3TB drives may spin at another, both between that 5400 RPM to 6000 RPM range.

Like many modern drives, the 3TB Caviar Green uses 4KB sectors internally however it emulates 512-byte sectors for compatibility reasons.

Unlike Seagate, Western Digital’s 3TB drive ships with a 3Gbps SATA interface. This isn’t a problem given that neither drive can push enough data to saturate the 3Gbps SATA interface. Without SSDs there’s very little reason for 6Gbps SATA support on desktop storage these days.

Where the 3TB Caviar Green really breaks the mold is that it is shipped with a HighPoint RocketRAID 620 PCIe SATA card. The purpose? Breaking the 2.19TB barrier of course.

The 2.19TB Barrier


View All Comments

  • pvdw - Wednesday, October 20, 2010 - link

    I use Linux MD RAID 10 (near-copies) on my home "server". For those who don't know, this is a non-standard RAID level that simulates RAID-10 using only two drives. In addition to redundancy this provides read speed improvements and some write speed improvement. I've set up automatic backups to protect from user error; and use Linux, so no viruses (yet). So I'm protected from all but fire/theft/bomb/hurricane/etc. For this I have off-site storage that syncs on a less frequent basis.

    Since we've had a number of power cuts here recently, the RAID setup also gives extra security.

    Also, I don't know where you get your data from. None of my customers have lost data due to malware (I recover data from systems riddled with them), theft, or fire, but they have due to disk failure. I would put user error at the top of the list. I can see theft moving up the list due to the increase in portable data storage (tablets, smartphones, etc.)
  • daneren2005 - Wednesday, November 23, 2011 - link

    You must be kidding me. Although it happens, not a single person I know has ever had a fire in their house. House break ins once again happen, but are not every day occurrences. I haven't heard of a widespread wipe virus since the early XP days. And when it comes right down to it, the common backup method (external HDD) prevents NONE of these things either. For 99.9% of the population, a RAID 1 provides IDENTICAL protection as an external backup drive. Especially since most consumer backups delete files that were deleted on the main drive, anything but a immediately noticed user error/virus wipe (and usually getting it out of the trash is going to be enough for these cases) would be propagated to the external drive as well.

    Now I both backup (update ~once a moth and store at brothers house) and RAID my data, but I do both because neither is enough by itself, but RAID isn't any less of a backup option then external backups.
  • CharonPDX - Tuesday, October 19, 2010 - link

    I've had Intel Desktop boards for a few years that support EFI boot. I installed Windows 7 this way onto a 3 TB Intel chipset RAID a while ago, no problem. (Boot to the EFI installer on the Windows 7 disc, rather than the BIOS installer.) Reply
  • TSnor - Tuesday, October 19, 2010 - link

    re: "Simply look at worst case seek time and you’ll get an idea for how quickly the platters are spinning" Worse case seek time should be the time it takes the heads to move from one extreme to another. While there might be a correlation between seek time and RPM, it would be because high performance drives tend to maximize both and green drives accept compromises on both.

    re: "Random performance is significantly lower, presumably because of the translation that happens at the USB controller level. " No, reading random 4K records is much harder for disk drives than reading sequential data. The R/W heads need to get positioned to the correct track between each random IO operation (that's the 'seek time' above) and the correct data has to rotate under the R/W heads (that's rotational latency effected by drive RPM). Reading sequential data the disk drive just reads each record as it comes under the R/W head, with a 1 cylinder (very short) seek to get to the next cylinder. This is why rotating disks can compete with SSDs for sequential data but get crushed on random data.
  • dertechie - Tuesday, October 19, 2010 - link

    He's comparing the 4K reads of the external drive to the 4K reads of internal and other HDDs, not to sequential reads. If you actually look, you'll note that the drive lost over half of its random 4K read performance when using it over USB3 (0.18 MB/s) compared to the numbers it posts as an internal drive (0.40 MB/s). Write performance also dropped compared to internal, but not as much. Reply
  • TSnor - Tuesday, October 19, 2010 - link

    re: "If you actually look..." ok. I agree with you. Reply
  • Sufo - Wednesday, October 20, 2010 - link

    um, pretty sure he was comparing the internal drive to the external one here (so essentially sata to usb 3). I would be surprised if Anand had forgotten that random reads/writes are slow work on mechanical drives - it's not been that long since he published the last round of articles on the subject... Reply
  • Sufo - Wednesday, October 20, 2010 - link

    oops sorry, didn't check next page >_< Reply
  • Dainas - Tuesday, October 19, 2010 - link


    Can you please do some reviews on Samsung's Spinpoints? Only asking because Western Digital and Seagate always seem to have this or that issue with their +1TB drive. Also from what I've seen Samsungs efforts are also consistently faster and more reliable. Would be nice to know what you think of them.
  • musicman1352000 - Tuesday, October 19, 2010 - link

    Yes please!

    Also, what happened to the noise figures?

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