• WD Green 2TB Variable RPM HDD ($72) – WD20EZRX.
• WD Blue 1TB 7200RPM HDD ($53) – WD10EZEX.
• WD Black 2TB 7200RPM HDD ($132) – WD2003FZEX.

WD Blue, Black, & Green Specs

The problem with “general rules” in the hardware space is that they lead buyers to believe there's a clear buying hierarchy without regard to use case scenarios. WD's general rule is Black > Blue > Green, but it's not always that simple – there are different use case scenarios attributed to each color, and “best” is classified more by the usage than by the color of the label on the drive chassis.

WD Green Pros & Cons

The WD Green HDDs have had a shaky history. In concept, WD Greens were an attempt at affordable archival storage with a variable RPM, theoretically allowing boosted speed during higher load times and an overall lower power consumption. The RPM for WD Green drives isn't advertised, but it is generally understood to rotate between 5400 – 5900 revolutions per minute.

Earlier revs of the WD Green drive exhibited failure from header disconnects and seek errors, attributed to the variable RPM. These issues have been largely resolved with the newer WD Green drives.

WD Green's primary advantages are regarded as:

• Higher capacity at a more affordable price.
• Lower power consumption.
• Useful as cheap, archival storage.
• Quieter.

Its disadvantages are:

• Slower speeds that are inadvisable for primary and gaming HDD usage.
• Slower wake and seek times.
• Lower reliability over its life.
• 2-Year warranty.

WD Blue Pros & Cons

WD's most recent Blue HDDs use a single 1TB platter, which allows for higher speeds due to its higher data density. Due to the density of the disk, the travel requirement on the header is minimized (more data in a square inch, so less movement is required) and seek times are reduced. This increases raw speed beyond what is possible even on some of the WD Black drives. Higher data density also reduces cost, as a single 1TB platter has a cheaper BOM than multiple platters.

The Blue drives ship at a maximum capacity of 1TB (1 platter, unless it's an older model) and are always 7200RPM. In the event an SSD isn't present, we generally encourage 7200RPM HDDs as the baseline for primary and gaming drive usage.

Cache for a WD Blue HDD tends to be 64MB, which is more than enough for higher-speed bursted operations; consumer HDDs will generally never (or very rarely) utilize >64MB cache.

The warranty sits at 2 years, less than half of the WD Black's 5-year warranty.

WD Blue's primary advantages are:

• Higher speeds – 7200RPM makes it ideal for primary drive and gaming use.
• Highest density – best cost-to-performance ratio and speed, even over WD Black.
• Relatively quiet for the speed.

WD Blue's disadvantages are:

• Max 1TB capacity.
• 2-Year warranty.

WD Black Pros & Cons

Performance industries have adopted “black” as a general indicator of a flagship device, including nVidia's Titan Black. Somewhat confusingly, WD's Blue drives recently surpassed WD Black in performance when the 1TB platters were adopted. WD Black drives have now been updated to utilize 800GB platters, reclaiming some speed, but are billed more heavily for high-endurance, high-reliability use than for raw speed.

WD Blacks operate at 7200RPM and scale to 4TB ($230), making increased capacity one of their biggest advantages over WD Blue. WD Black drives use a beefier chassis than WD Blue as a part of their vibration control. The drive chassis is built to help handle high-speed fan vibration and odd mounting orientation (think: mini-ITX), reducing the chance of read errors and keeping the header in place.

For users hoping to buy 2TB of WD storage on 7200RPM platters, this is the only real performance-class consumer option. A 5-year warranty accompanies the WD Black drive, making for a more tempting option for production rigs and performance computing.

WD Black's primary advantages are:

• A 5-year warranty.
• Up to 4TB of 7200RPM storage.
• Improved endurance in production environments.

WD Black's disadvantages are:

• Significantly noisier than WD Green and Blue.
• More expensive per GB.

WD Black vs. Blue Comparison & The Best HDD for Gaming

Ultimately, WD Green HDDs are only useful for mass archival storage at a budget. These are the drives you buy for storing mass media (movies, music, photos) that doesn't require high-speed access and doesn't get accessed constantly.

WD Blue and WD Black are the best two Western Digital options for gaming, if we're ignoring competitors momentarily. WD Black 7200RPM HDDs ($100-$230) make the most sense for high-performance computing that requires increased capacity and endurance, though the vast majority of gamers would do well to opt for 1TB WD Blue 7200RPM HDDs at around $54.

In speaking with Western Digital, we learned that there's not any real technological difference between Blue and Black in terms of the processing and caching architecture; the differences primarily stem from platter density, platter count, and the chassis.

Of course, for the ultimate in performance and reliability, we recommend an SSD (Crucial's MX100 256GB SSD is only $111).

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- Steve “Lelldorianx” Burke.