SSD drives continue to evolve as evident by the release of Solidigm’s NVMe (Non-Volatile Memory Express) SSD drives. NVMe is a specification that was designed specifically for flash memory communication and allows solid state drives to connect to the system using the PCIe bus giving these types of Solid State drives the ability to reach their true throughput potential. In addition to being extremely durable, the benefits of NVMe with PCIe over traditional SATA SSD drives are reduced latency, increased IOPS, and even lower power consumption.
As is the case with previous generations, not all SSDs are created equally. Solidigm NVMe SSD drives use their own engineered and manufactured controller, NAND and firmware which offers improved internal bandwidth as well as reduced internal latencies. Solidigm offers PCIe/NVMe SSD in several form factors including U.2 2.5”, M.2 22×110, and E1 (Ruler) options providing capacity up to 15.6 TB using Intel TLC NAND. There are distinct advantages to each form factor starting with the 2.5” U.2 disk drive style that allows you to connect the drive using standard or hot swap drive enclosures, the space saving M.2 22×110 provides adding capacity in standard or small footprint servers without consuming disk bays, and the innovative E1 that provide massive SSD capacity in a storage server.
Performance
SSD drives deliver many benefits for both enterprise and client users including high performance, extreme durability, and low power consumption. No matter the interface, SSD drives still maintain these inherent characteristics but with NVMe SSD drives users get the benefits of even higher performance mainly measured in IOPS (Input/Output).
As previously mentioned, the Solidigm NVMe family of drives use the PCIe 3.0 x4, PCIe 3.1 x4, or PCIe 4.0 x 4 slot which delivers up to 8GB/s of throughput which is 2x that of PCIe 3.0 x4 and is over 13x that of the 600MB/s provided by SATA 3. Transfer Rate is not the only limiting legacy technology for traditional SSD drives. In addition traditional SATA 3 SSD drives utilize the AHCI interface. This communication protocol was designed for high latency mechanical disks and actually resulted in high CPU usage when coupled with low latency SSD drives.
| NVMe | AHCI | |
|---|---|---|
| Latency | 2.8us | 6us |
| Maximum Que Depth | Up to 64K queues with 64K commands each |
Up to 1 queue with 32 commands each |
| Multicore Support | Yes | Limited |
| 4KB Efficiency | One 64B fetch | Two serialized host DRAM fetches required |
Removing the bandwidth limitations of SATA and shedding the AHCI communication protocol with technologies such as NVMe and PCIe that were specifically designed for SSD devices results in dramatically improved performance. When measuring IOPS, Solidigm NVMe drives are capable of up to 700,000 IOPS compared to the best performing SATA drives which could potentially achieve up to 100,000 IOPS. This not only results in higher performance but also better CPU utilization particularly in applications that have multiple processors.
| Protocol | Solidigm NVMe | SAS HDD | SATA SSD |
|---|---|---|---|
| Random 4K Read/Write (IOPS) | Up to 700,000 | Up to 190,000 | Up to 100,000 |
| Sequential R/W Performance (MB/s) | Up to 6,500 | Up to 1,000 | Up to 550 |
| Form Factor | 2.5”, U.2 | 2.5” | 2.5” |
| Interface | PCIe 4.0 | SAS 12 GB/s | SATA 6GB/s |