Toshiba's new MG04ACA series are Enterprise class HDDs available in increments of 1TB, from 2TB to 6TB and ship with either 4K or 512B emulation depending on your preference.  Mad Shrimps just wrapped up a review of the 4TB model which certainly cannot match a SSD for speed but it is rated for 1400000 hours and workloads of 550TB a year, constant usage.  You do pay a premium for enterprise level drives but spinning rust is still far more economical in high densities that flash based drives are.  If you are looking for reliable HDDs for your servers, check this review out.

"The new MG04ACA series from Toshiba is composed from drives which are meant for enterprise, mission-critical applications, while sporting higher transfer rates and capacities. The tested sample comes with 128MB of cache and comes in two versions, depending on the applications it is needed for: with 512 sector emulation or strictly with 4K sector. Make sure to choose wisely which drive is for you and your setups in order to bypass any incompatibilities which may arise."

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