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

  • risa2000 - Wednesday, October 20, 2010 - link

    I have 4 years "old" Intel board D975XBX, which sports EFI boot. The only effect I saw so far, it confuses Win 7 Ultimate installation disk to the point it presents strange menu after the boot, which does not display the choices. Searching on Internet returns this is related to EFI (since it has been also observed on Intel Macs). So EFI has been around for quite a while already - whether it works is different story.

    For 4KiB sector size. I hope WD will soon come out clear on this point and have their drives to report it properly. So far I have seen two Caviar Greens (640G and 2TB), which both claimed logical and physical size 512b. It seems the situation now is forced by Windows XP compatibility, but it then has negative impact on any other system and performance if not handled manually and correctly.

    For example the mentioned 4K random read&write: Were those 4K blocks aligned to physical disk sectors or were they random on 512b boundary?
  • alpha754293 - Wednesday, October 20, 2010 - link

    I thought that LBA48 was supposed to fix the whole LBA32 issue?

    At 48-bits of Logical Block Addressing, that would be 2^48 blocks. Multiply that by even 512-byte sectors, you end up with 144,115,188,075,855,872 bytes of storage max. (144 TB).
  • QChronoD - Wednesday, October 20, 2010 - link

    This drive looks very interesting. I'm looking to add a bunch more storage to my computer and these new 3TB are very tempting especially with such a small price premium.

    Since I have 8 open drive bays but no free SATA ports, I'm debating between getting a good 12 or 16ch raid card and then running one ginormous RAID5 or 6, or just picking up a pair of cheap SATA cards and dealing with a dozen drive letters.
    ATM I'm leaning towards RAID since I think I would be less likely to loose data. Anyone's opinion on which way I should go (or what cards/drives to get)
  • mark3450 - Wednesday, October 20, 2010 - link

    My understanding is that Western Digital is now deliberately crippling RAID support in all new consumer level drives. Specially by removing the users ability to set what WD terms the "Time-Limited Error Recovery" flag in the drives firmware.

    Anyone have and idea if this is also the case for this drive?
  • JNo - Wednesday, October 20, 2010 - link

    First of all, I think most of us know that a 3TB 5,400rpm (ok 'up to 6k rpm') is not meant to be a boot drive so there is not much point reiterating it so many times or carrying out 20 different tests that all show it. However I do take point with one statement:

    "At $239 for an internal drive, the 3TB offering isn't too expensive. You can shave off another penny or two per GB if you go with a smaller drive, but if you want the space of a single drive Western Digital's offering isn't a bad deal."

    A penny or 2 per gigabyte is a *huge* amount when gigabytes are only 3-6p each.
    In the UK, the pre-order price for this drive ( is £189.05 or 6.3p/gb whereas the 2TB caviar green (WD20EARS) is only £73.21 or 3.7p/gb. That's 42% less! I know there is always a premium for cutting edge but I'm not sure there are too many people for whom 3TB is mission critical where 2TB would fail.

    So unless you have an SFF/HTPC with v limited drive bays, the 2TB drives win everytime. You've admitted yourselves that speed is not a factor, that these are slow storage drives, so the only metric of interest, really, is cost / gb. There's a lot of analysis this write up for a straight forward conclusion unfortunately.
  • softdrinkviking - Wednesday, October 20, 2010 - link

    So, does using Linux Effect the hardware requirements?
    You still need a mobo with efi support, right?
    And you also are restricted by SATA and have to use IDE?
  • mariush - Thursday, October 21, 2010 - link

    Is Anandtech so poor that they can't buy a license for that software used to determine the transfer speed? It shows "trial version" in the top left corner...

    I guess the extra cost is also in part because of the controller, which is a custom HighPoint RocketRAID 620 (see that's available for 60$ ... well custom, if you think custom means removing the beeper.

    I guess if you need a sata controller or you wish to sell the controller on eBay it would be worth getting this drive.
  • marsbound2024 - Thursday, October 21, 2010 - link

    "It's barely any faster than an old Seagate Barracuda ES and even slower than the old 150GB VelociRaptor. "

    I believe it is just "Raptor" not "VelociRaptor."
  • Hrel - Thursday, October 21, 2010 - link

    The only way I'd forgo using a 7200rpm drive is if I could get a 500+GB SSD for under 100 bucks. That's the only way I could install every single program I use and have enough space space to keep things running smoothly. And that's today, I'd want room for expansion, more games, bigger games, bigger media editing programs. SSD's are still WAY WAY WAY too expensive. The price of them needs to come WAY down or they'll never see market penetration. I'm honestly shocked they're still so expensive. Where's the sub 50 cents per GB SSD? Reply
  • Hrel - Thursday, October 21, 2010 - link

    I've seen 1TB drives for 50 bucks. That's 5 cents per GB. You'd think we could get at least 25 cents per GB in SSD's. Hell, they're only 5 times faster at best, so 5 times more/GB seems totally fair. Greedy Bastards; most us are still struggling out here and they're just getting greedier. Reply

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