“The coolest consumer devices use NVM (non-volatile memory)” said Intel Fellow Knut Grimsrud, who gave a keynote speech at this week’s Flash Memory Summit http://www.flashmemorysummit.com. We’ve seen SSD (solid-state disk) performance advances on the order of 20x from 2005 through 2011, just based on data from three generations of Intel’s SSDs he said. Then Grimsrud looked forward to the next 20x in performance improvement—from 20,000 to 40,000 IOPS (I/O operations/sec) to more than 1 million IOPS. Surprisingly, it’s not the foundation NAND Flash technology that’s needed to get there. SSDs are inherently parallel devices with several banks or ranks of NAND Flash devices that can operate simultaneously. No, the bottlenecks are the SSD I/O interface and the OS driver.
Consequently, said Grimsrud, we’ll be using something like an 8x PCIe Gen3 interface to connect these future SSDs and we’ll need a more efficient programming interface like NVM Express (NVMe), released just last March by the NVMe Work Group (www.nvmexpress.org). A slide Grimsrud presented during his keynote showed command-processing overhead dropping from 7.6 microseconds to 1.6 microseconds just by switching from a SAS I/O driver to an NVMe driver.