Stefan Mileschin

At OCP Summit last week, Marvell unveiled a new generation of NVMe SSD controllers and a unique NVMe switch that blurs the lines between a standard PCIe switch and a traditional RAID controller.

The most straightforward of Marvell's three new NVMe products is the 88SS1098 "Zao" NVMe SSD controller. With 8 NAND channels and a PCIe 3 x4 host interface, the 88SS1098 is the direct successor to the 88SS1093 "Eldora" and 88SS1092 "Eldora Plus" controllers for high-end client SSDs and low-end enterprise NVMe SSDs. Performance increases will be enabled primarily by the introduction of Marvell's fourth-generation LDPC error correction engine with improved throughput, and by a 50% increase in the maximum supported NAND interface speed. The new controller also adds a fourth ARM Cortex-R4 CPU core. The DRAM controller has been upgraded to support LPDDR4, which should help reduce power consumption of M.2 NVMe SSDs. Up to 8GB of DRAM is supported, matching the 88SS1092's primary advantage over the 88SS1093 that is limited to 2GB of DRAM.

A number of new enterprise-oriented features have been added to Marvell's latest NVMe controllers. The PCIe host interface can be operated as a dual-port pair of PCIe 3 x2 links for high availability. SR-IOV virtualization support is included with support for up to 64 virtual instances of the controller. The new NVMe Streams and IO determinism features are supported, allowing drives to offer improved performance and endurance under mixed workloads when the host system's NVMe drivers support those features. Even without streams and IO determinism, latency QoS is improved by the migration of more controller functionality from the CPU cores to dedicated fixed-function hardware, and better support for suspending in-progress NAND program operations to perform a quicker read operation. The new controllers support a total of 132 queue pairs of up to 256 I/O commands in flight, so the controller can handle intense workloads and won't require host systems to share queues between CPU cores. QLC NAND is officially supported.

https://www.anandtech.com/show/12577...le-nvme-switch