SAS 24G+ Unleashed: Next-Gen Storage for Hyperscale Data Centers

For today’s hyperscale data centers, although solid-state drives (SSDs) are gradually transitioning to products supporting the NVMe protocol with PCIe physical interfaces, many applications still rely on Serial Attached SCSI (SAS) technology. SAS storage is far from obsolete. Recently, the SNIA SCSI Trade Association Forum (STA) and the INCITS/SCSI Standards Organization introduced the SAS 24G+ specification, specifically targeting the next generation of hyperscale data center hard disk drives (HDDs) and SSDs.

According to TomsHardware, the SAS specification upgraded data transfer speeds to 2.4 GB/s in 2020, with the first HDDs supporting this interface already on the market. The new SAS 24G+ specification offers the same performance while adding five new features aimed at enhancing storage performance for traditional servers and hyperscale data centers.

The SAS 24G+ specification introduces the Command Duration Limits (CDLs) feature, which controls HDD latency, ensuring operations are completed within specific timeframes, thereby guaranteeing efficiency and reliability in large-scale data environments. Another feature related to HDDs is the “Format Preset” function, which simplifies the management process for CMR and SMR HDDs, reducing the number of models used in data centers. Additionally, the “Logical Depopulation” feature identifies and removes faulty platters from datasets running in hyperscale applications. For SSDs, the “Rebuild Assist” function helps identify unreadable partitions that need to be rebuilt from other sources. The Persistent Connections feature optimizes performance by maintaining an open state, eliminating the wear and tear from repeatedly opening and closing connections, which is particularly beneficial for high-performance SSDs.

Cameron T. Brett, Chairman of the SNIA STA Forum Board, stated that the key features of the SAS 24G+ specification encompass both HDDs and SSDs, marking a significant advancement for the industry. It benefits storage systems in hyperscale data centers and traditional servers by providing high performance, reliability, and scalability. The SAS 24G+ specification continues the legacy of the SAS and SCSI systems, which have been around for over 30 years, elevating data storage to a new level.