The difference between blue disk, black disk and green disk of WD

Black disk
High performance, large cache, fast 
Fit: enterprises, throughput large server
Code: LS WD Caviar Black desktop
HDD 2 TB, SATA 3 Gb/s, 64MB cache, 7200 RPM suitable for the ultra-high performance of high end computers. It equipped the most sophisticated high-capacity hard disk for your personal computers. WD Caviar Black HDD has high performance electronic architecture and rock solid mechanical structure, it provides perfect store solution for your fully equipped PC or high-performance game. Low heat HDD running, non-contact head technology and highly sophisticated vibration protection, which ensure higher reliability and more durable data processing capability.
Main features: High performance electronic sarchitecture, Dualprocessor- double processing capacity, maximize performance, Large cache-larger, faster 64 MB cache means better performance, Rock solid mechanical structure.
Dual Drive System - Use head positioning system of dual drive, which could significantly improve the positioning accuracy of data tracking. Main driver using conventional electromagnetic actuator principles provides coarse-grained displacement. Spare driver using pressure electric technology optimizes head positioning so that it achieves a higher level of accuracy. (limited 2 TB)
Stable Trac - The motor shaftat both endsare fixed to reduce fibrillation of system operation and stabilize platters, so that you could seek track accurately when read and write.
No Touch ramp load technology - The recording head never touch the disk media to ensure minimize the wear of the recording head and media and provide better protection in transportation.
Large capacity – the capacity of WD Caviar Black SATA HDD has been reached 2 TB.
Compatibility – we tested hundreds of systems and many platforms in FIT Lab and mobile communication Lab to make users believe our HDDs could well run in their system. 5 years maintenances is most suitable for high-performance computing applications, such as media videos, photo edits and high performance gaming machines. How does these WD HDDs protect your data?
Data Lifeguard is a senior data protecting functions, which including anti-vibration, environmental protection system, real-time embedded error protection and repair function.
Data Lifeguard technology of WD could automatically find, isolation and repair problems which may caused by HDD overused. Data Lifeguard Tools is software tools specially design for WD HDDs, it could cooperate with embedded Data Liftguard tools and make HDD installed, diagnosed and repaired easy. Short Guard real time protect HDD against damage from the instant bumps and vibrations when running. This technology enables WD Caviar drives to achieve industry-leading shock specifications.

 Blue disk
Household, Cost-effective, Overall more balanced, Longest life
Fit: store data and common use
Code: KS WD Caviar Blue SATA HDD, 1TB, SATA 3 Gb/s, cache 32MB, 7200 RPM is suitable for performance and reliability for everyday computing applications. Rely on SATA and PATA interface and 32MB cache, the series HDDs have overall stronger performances. It is provide you the suitable HDDs and believe that all WD Caviar Blue HDDs could fulfill the highest quality and reliability. In order to facilitate you to choose HDDs, we make all common WD Caviar SE16, WD Caviar SE and WD Caviar into one category, which we called WD Caviar Blue. These HDDs are built by the quality standard of acclaimed Western Digital and they have many features related to performance.
Main features:
PATA interface - Enhanced Integrated Drive Electronics(EIDE) HDD, also called parallel ATA(PATA) HDD, which has been become the standard of computer industry for 10 years.
SATA - Serial ATA（SATA）HDD is become the new standard rapidly. Motherboard manufacturers installed SATA interface in their board card. Compare with PATA HDDs, SATA HDDs’ cable is narrower so that use SATA HDD can Increase air flow and reduce the confusion of computer case.
Performance difference – The highest data transfer rate of PATA HDD supports is 100MB/s and all WD Caviar Blue SATA HDDs are support 3 Gb/s transfer rate.
How to choose – Our concise interface guide could help you to choose export.
Reliable performance – Rely on SATA and PATA interfaces and up to 32 MB cache. These series HDDs have overall stronger performance.
Capacity – We provide WD Caviar Blue HDD capacity is up to 1 TB, it could fulfill your store needs.
Reliability – We know your data is important deeply and we are devote to protect these important data through highly reliable products, advanced data protection technologies and excellent customer support service.
Low heat – Maintain low heat of HDD could improve its reliability. WD is always find new create way to low HDD’s working temperature.
Quiet operation – The technology is high