Fujitsu Laboratories has developed a solid-state drive (SSD) in which flash memory can be directly controlled by software running on a server. The result is a processing performance three times faster than that of ordinary SSDs. With in-memory databases, which enable high-speed analysis by loading data onto servers on a type of memory called DRAM (Dynamic Random Access Memory), when the volume of data exceeds the capacity of memory, lags in access to storage and other factors reduce processing speeds. One way of resolving this issue is to expand memory capacity by using high-capacity SSDs, and progress is being made on technologies for separately using DRAM and memory expansion.
SSDs are equipped with multiple flash memory chips, but from the perspective of software running on a server, the inside of an SSD is a black box, and read/write operations cannot be directly performed on the flash memory inside. As a result, there are times when read/write instructions are competing for the same flash memory chip which is a factor that degrades performance.
Fujitsu Laboratories has developed a prototype PCI Express SSD that enables read/write commands for each flash memory chip directly from software. The software-controlled SSD was equipped with 16 control channels and 256 flash memory chips, in which the interface enables read/write commands directly to each flash memory chip from server software.
The company developed a "read-ahead" feature which, in accordance with the access pattern, enables parallel data retrievals from multiple flash memory chips without the instructions interfering with each other. By loading data into DRAM before using the data from the in-memory database, data usage and data loading are processed simultaneously, enabling high-speed big data processing, with no access lags, even with limited DRAM capacity.
With the newly-developed software-controlled SSD and technology for data "read-ahead," Fujitsu Laboratories was able to improve processing performance by roughly three times compared to a conventional SSD, even with limited DRAM capacity.
Fujitsu says that the SSD achieved transmission speeds of roughly 5.5 gigabytes per second.
Fujitsu Laboratories plans to increase the parallelization of data retrievals and consider applications beyond in-memory databases with the aim of bringing this technology into practical use in fiscal 2017.