Japanese hardware vendor Buffalo claims to have worlds fastest external hard disk drive, the HD-GDU3. The boost in speed is achieved by the addition of 1 GB of DRAM that acts as a cache. Buffalo specifies that the HD-GDU3 is able to achieve transfer speeds of up to 408 MB/s. To be able to reach this speed it will need to be connected to an USB 3.0 port.
The 408 MB/s means that thousand 800 KB images can be transferred in 3.5 seconds on a Core i7 with 4 GB RAM and an internal SSD. The super fast 1 GB DRAM cache is used to store the data before writing it to the slower HDD.
Other manufacturers have used NAND memory in their HDDs but that isn't as fast as DRAM. However the latter loses its data once the power is lost and Buffalo hasn't disclosed how it deals with that. The drive will become available in Japan at the end of February in 3TB, 2TB and 1TB versions. The 3 TB version will cost about $300. It's unclear whether and when it will become available in other countries.
