IOPS vs Throughput: What Is the Difference and How Do They Affect Storage Performance?

IOPS (Input/Output Operations Per Second) and throughput are key metrics used to measure performance for storage devices. However, IOPS and throughput are fundamentally different, and measure different aspects of performance. As modern businesses continue to adopt more digital technologies and rely on non-hardware storage technologies such as cloud and virtualization for their data, understanding the difference between IOPS and throughput is becoming increasingly important to build your ideal storage environment.

What Is IOPS?

As the name implies, IOPS measures the number of input and output (i.e. read and write) operations that can be performed on a storage device within a single second. IOPS is a standard performance benchmark for any storage device, including hard drives (both HDD and SSD), flash drives, and network attached storage (NAS) devices as part of a storage area network (SAN). While IOPS itself doesn't indicate the amount of data that the drive can process, it is nevertheless a critical metric for storage devices because it directly frames the device’s ability to handle requests from applications and users.

Typically, a higher IOPS number indicates better storage performance and faster response times, but measuring the exact IOPS can be tricky because there are so many factors that determine performance. For example, the type of drive is an important factor, as SSD will have different performance calculations compared to HDD, even if they are the same size.  In addition, IOPS can differ depending on whether the data is accessed sequentially or randomly, and IOPS can also be different for read and write operations - for example, HDDs generally will have higher IOPS for sequential data writes.

The performance of data-intensive applications, such as databases, ERP systems, and virtual machines, is directly affected by the number of input/output operations that a storage system can execute. Therefore, higher IOPS can be a good indicator that a storage system will meet your requirements.

What Is Throughput?

Throughput, on the other hand, is a measure of how much data can be transferred in a given amount of time, usually measured in bytes per second. Throughput takes into account the size of the data being transferred, as well as the time it takes to transfer that data. Throughput is helpful in estimating requirements of data-intensive applications (especially multimedia and big data), as well as planning bandwidth.

In terms of performance, higher throughput generally indicates better network performance and faster data transfer times. In contrast to IOPS, throughput provides a concrete assessment of storage performance, because it tells you how much data can be processed. You can use this metric to conclude whether a given storage device meets your IT environment requirements.

IOPS and Throughput on NAS Performance

While both IOPS and throughput are important metrics for measuring storage performance, they are not interchangeable. In fact, focusing solely on one metric at the expense of the other can lead to poor performance and user experience.

To understand the difference between IOPS and throughput, it’s helpful to think of a storage system as a highway. IOPS measures the number of cars (i.e., read and write operations) that can pass through a given section of the highway in one second. Throughput, on the other hand, measures the total amount of traffic (i.e., data) that can pass through the highway in one second.

If a highway has a high IOPS but low throughput, it means that many cars (i.e. read and write operations) can pass through the highway in a short amount of time, but the overall amount of traffic (data) that can be moved is limited. Conversely, if a highway has high throughput but low IOPS, it means that a lot of traffic (data) can pass through the highway in a short amount of time, but there may be delays for individual cars (i.e., read and write operations). To achieve optimal performance, both IOPS and throughput need to be considered and balanced. For example, in a database application where many small read and write operations are being performed, high IOPS is critical to ensure fast response times. However, if the application is transferring large files, such as multimedia or scientific data, then high throughput is more important.

Another important factor to consider is the impact of latency on performance. Latency is the time delay between when a request is sent and when a response is received. In storage systems, latency can be impacted by factors such as network congestion, disk access time, and processing overhead. High latency can slow down overall performance and lead to poor user experience.

Factors That Affect Storage Performance

When it comes to storage technology such as NAS, IOPS tends to take the spotlight, as many vendors use IOPS numbers to demonstrate how fast their storage system is. However, measuring storage performance solely through IOPS is only significant if the workload has high IOPS demands. Afterall, speed matters, and this is where throughput comes into play—the volume of data actually delivered to the storage device is an important component in real-world performance metrics.

Once you have determined the performance required, there are several NAS technologies and techniques that can be used to improve storage performance. One common approach is to use RAID (Redundant Array of Independent Disks) to increase IOPS and throughput on a NAS. RAID combines multiple physical disks into a single logical unit, improving both IOPS and throughput by distributing data across multiple disks.

Another approach is to use caching to improve performance. Caching involves storing frequently accessed data in a fast storage medium, such as RAM or SSD devices. By keeping frequently accessed data in a fast storage medium, the system can reduce the latency, thereby boosting performance.

Buffalo NAS with Optimized Storage Performance

The bottom line is: Both IOPS and throughput matter when it comes to storage performance.

Buffalo’s TS71210RH offers high performance for both IOPS and throughput. TS71210RH delivers enterprise-level server performance and a dynamic and stable platform for data-intensive IT environments. Designed to handle high workloads, the TS71210RH solution can act as production data storage, application server, large-scale data storage and backup, mission-critical file server, and more.With 4 native 10GbE ports, TS71210RH provides high bandwidth for blazing fast transfer speeds to accelerate any modern IT environment. Optimize data operations with efficient file sharing for collaboration, virtualization solutions, and fast data backup/recovery without missing a beat.