Technology Overview

Hard-disk drives (HDDs) are spinning disks so their mechanical actions can create a delay in data retrieval. With HDDs, there is a read/write head on the arm of the device that moves to find and access data while metal platters spin simultaneously. Solid-state drives (SSDs), built from silicon memory chips, have no moving parts, no rotational delay and near-zero seek time, which dramatically reduces response times. SSD data is stored on flash memory chips that are capable of retaining data without power. SSDs can be extremely valuable to applications that need high performance as measured by access latency and input/output operations per second (IOPS).

Reliability

Because SSDs don’t have any moving parts, they are nearly invulnerable to fail in vibration and high-shock environments or extreme temperatures. These traits—particularly the capability of operating in extreme temperatures—allows SSD-based systems to handle more applications in difficult situations where traditional hard drives can fail.

Data Read/Write Rates

As far as measurement, testing and industrial applications are concerned, data-access rates are extremely important. Since SSDs do not need to move drive heads or spin up the drive platter as in the case of traditional HDDs, data in SSDs can be accessed promptly. Due to the lack of these mechanical delays, SSDs exhibit significant increase in read/write rates. This performance boost adds to user productivity by enabling increased data read/write rates, faster loading of applications and decreased system boot-up/shutdown time.

Performance

It’s not only that SSDs have faster read/write rates than traditional HDDs, they also have better deterministic performance. Unlike regular HDDs, the performance of SSDs is almost constant and deterministic across the entire storage space. This is because of the constant seek times offered by SSDs.

This performance advantage can be explained by two key reasons. The first is file fragmentation. Over time, files become more fragmented, requiring a regular HDD to perform additional seeks to retrieve an entire file. This process decreases the effective performance of the HDD compared to the SSD.

The second reason is the method in which data is stored on an HDD. When data is first written to an HDD, it is stored in the sectors close to the outer edge of the spinning platters, which move faster as compared to the sectors nearer to the center of the platter. When the HDD fills up, the data is written to the slower-moving inner sectors, decreasing read/write speeds. Here's where SSDs have another advantage for not having moving parts. They are able to maintain the same level of read/write performance through the entire capacity of the drive.

Lower Power Consumption

Steadily increasing storage requirements pose power and performance challenges to data centers. SSDs have a significantly better performance-to-power rating than traditional rotating HDDs. The lack of a motor greatly reduces an SSD’s power consumption, so the drive draws less energy.

Local Server Advantage

SSDs have considerable advantages over HDDs when installed on a server. Not only will the system boot up considerably faster, it will also store and locate files faster. This can help facilitate applications and programs—allowing them to start and run at faster rates as well. An SSD will always outshine a HDD in terms of speed and overall performance. Transfer times are faster, and whether you are using the server for business or personal use, one equipped with SSDs is a good choice.

Web-Hosting Advantage

Using SSDs for web hosting will provide an advantage in the load time of your web site. Web sites hosted on SSD servers tend to load 2-5X faster than web sites hosted on servers with HDDS. You may find that the administration panel for your web host loads faster and is more responsive as well. SSD hosting can improve the user experience on your web site by allowing images and pages to load quicker.

Ease of Use

SSDs come in a form factor that is a drop-in replacement for existing 2.5-inch HDDs. They fit into existing HDD hot-plug bays and require no modification to operating system or infrastructure tools. The drives are recognized as standard SAS or SATA devices with no special changes in firmware or hardware. Although you cannot mix SSDs and HDDs in the same logical array, you can mix them within the system to provide a more effective use of both technologies.

Content Service Providers

No one is better at cost effectively deploying IT infrastructure than today’s major content service providers (CSPs). It may surprise you to know that CSPs are also leading the way for adoption of faster SSD storage as well. Generally, SSDs are thought of as too expensive. This is not the case. CSPs are by far the leading consumers of SSD technology, consuming petabytes and petabytes of SSD storage. The CSPs fully understand the value that high-speed, scale-out SSD storage brings to their infrastructure. When you couple the highest-end CPUs with high-speed networking and SSDs, you can convert from traditional SAN and NAS storage architectures to more efficient and higher-performance SSD storage architectures. This moves more data closer to the CPU, unleashing the solution performance, and providing the best utilization and flexibility within the data center. 

SSDs: SAS/SATA vs. NVMe

SAS/SATA were originally designed for HDDs and have limited the SSD transfer rate. For instance, SATA III, a common interface for current SSDs, has a maximum data-transfer rate of 600 MB/s. SSDs have far more in common with fast system memory than with the slow hard drives they emulate. It was simply more convenient to use the existing PC storage infrastructure, putting SSDs on relatively slow (compared to memory) SATA and SAS. For a long time, this was fine as it took a while for SSDs to ramp up in speed. Those days are long gone.

The future of storage lies with direct connection to the CPU's host bus also known as PCIe. New PCIe SSD uses non-volatile memory (NVMe), which was designed for flash and new memory technologies. These drives offer significant performance improvements and come in sizes to support large data center workloads. NVMe SSDs talk directly to your applications via the PCIe bus, boosting I/O and reducing latency to scale performance in line with your processing requirements. The performance of NVMe SSDs can outperform the SAS/SATA SSDs by six times.

SSD Performance Report

A performance report was done comparing a legacy server with spinning HDDs to a new server with standard SATA SSDs and the same server with NVMe SSDs.

Using SATA SSDs the new server was able to perform the work of two of the legacy servers. After upgrading the server to NVMe SSDs, it was able to perform the work of four of the legacy servers.

Summary Comparison:

Hard-Disk Drive (HDD) Solid-State Drive (SSD)
Rotating platters and mechanical arms, comparatively fragile construction No moving parts, more rugged construction
High energy consumption Low energy consumption
Increased file fragmentation = decreased performance Fragmentation not an issue = results in consistent performance
Drive spin-up time and mechanical arm movement = comparatively slow response and performance No drive spin-up time, no mechanical arm movement, minimal latency = fast response and performance
SAS / SATA SAS / SATA and NVMe

Lenovo SSD Categories:

  • Enterprise Capacity SSDs – Highest capacity 2.5-inch SSD on the market delivering the performance and benefits of SAS at near-SATA prices. Engineered to deliver efficient performance for enterprise needs, especially read-intensive data center application workloads.
  • Enterprise Value SSDs – Provides both performance and endurance in a cost-efficient design. Engineered to deliver efficient performance for enterprise needs, especially read-intensive data center application workloads. 
  • Enterprise SSDs – Provides low latency and high-performance solid-state storage options for variety of workloads from write-intensive data center workloads such as database, HPC, virtualization and big data to day-to-day operational tasks.

For more information, see Lenovo SSD Storage Options for Servers or visit our Lenovo enterprise web page.