When it comes to performance, Toshiba was unable to provide performance metrics other than I/O's per second (IOPS) and seek times. Toshiba said its drive has an average seek time of 12 milliseconds, compared to the Momentus XT's 11ms read seek time and 13ms write time.
The Toshiba hybrid has a maximum 4,000 random IOPS using 4K block sizes. Without aid of the SSD element, the Toshiba hard dirve has a maximum data transfer speed of 1,469 Mbps or 184 MBps, said Kim.
"What we've done with our hybrid drive is fully married the benefits of Toshiba's knowledge of rotating media with the in-house expertise, IP and technology know-how in NAND flash," Kim said.
Hybrid drive adoption slow
Hybrid drive adoption has been unremarkable, said the market research firm IHS iSuppli. A report released earlier this year said that while sales of hybrid drives are expected to double over the next year, that increase cannot compare with sales of pure SSDs, which are expected to skyrocket 2,660%.
Hybrid drive shipments will reach just two million units this year, up from 1 million units in 2011. IHS iSuppli predicts hybrid drive shipments will reach 25 million units by 2016.
Pure SSDs are currently the leading storage type in ultrabooks, but low-capacity (20GB to 40GB) cache SSDs, which run along side hard drives in notebooks, will see shipments rise even more this year to 23.9 million units, up an astounding 2,660% from just 864,000 units in 2011. Shipments will then jump to 67.7 million units next year, cross the hundred-million-unit mark in 2015, and hit 163 million units by 2016, said IHS iSuppli.
Higher capacity, pure SSDs (with 80GB to 512GB capacity) will reach 18 million units shipped this year and 69 million by 2016, said iSuppli.
Toshiba scientist Fujio Masuoka invented both NAND and NOR flash memory in 1980. It is Toshiba's ownership of flash intellectual property that Kim said will set it apart from other manufacturers of hybrid drives.
For example, like Seagate's Momentus XT hybrid, Toshiba's drive will have self-learning caching algorithms, which overtime will determine what data should be stored on the flash and what should be stored only on the rotating media for long term access. All data that is written to the hybrid drive's flash cache is automatically written to spinning disk for resiliency, but if access to the data slows over time, it will be removed from cache and placed only on the spinning disk, Kim said. Data that's most frequently access will be kept on the 32MB of RAM, Kim said.