Throughput vs. bandwidth: The core elements of network performance

What is throughput in networking?

The term throughput refers to the speed at which a data packet can be moved from one node to another on a network. Throughput is measured in bits, bytes, or data packets per second, which describes the time it takes one of these units to move through the network.

Being able to test a system’s throughput is useful when assessing routing efficiency and a network’s overall performance. A system might have the capacity to move a certain amount of data (measured in bandwidth), but when determining a network’s practical performance, throughput is the primary metric used.

Bandwidth and throughput are very similar, but the key thing to understand is that throughput equates to actual speed. The higher your network’s throughput (the more bits, bytes, or packets moved per second), the better your network’s performance. High throughput indicates that data is being processed and routed rapidly and effectively.

What is bandwidth in networking?

Bandwidth refers to a network’s maximum transfer capacity for data. The more data that can be moved at once within a network, the higher the bandwidth. Higher bandwidth usage activities include downloading large files, playing online games, and streaming. If your bandwidth is too low, you may notice network congestion and, as a result, a slower network connection.

We measure bandwidth in bits per second (Bps), kilobits per second (Kbps), megabits per second (Mbps), or gigabits per second (Gbps). A measurement of bandwidth does not represent a network’s speed in the way that throughput does, although high network bandwidth usually equates to faster speeds.

Think of bandwidth as the highway on which the cars (data packets, in this analogy) move. The wider the road, the more data can move back and forth at the same time. You can have high bandwidth, meaning that your network can technically move a large amount of data at once, but inefficient routers and other technical issues could still result in slow data speeds and low throughput.

In our highway analogy, the width of the road (bandwidth) can allow large amounts of traffic to be in motion but does not necessarily increase the speed (throughput) at which individual cars — or data packets — move. When troubleshooting networking problems, it’s important to measure both bandwidth and throughput.

Why are throughput and bandwidth important in networking?

Throughput and bandwidth are important in networking because they allow you to monitor and assess network performance. It’s not a question of throughput vs. bandwidth — you should track both.

Being able to measure network bandwidth helps you to determine what kind of activities your network can handle. For example, if you’re going to run multiple devices on a Wi-Fi network, you should set up a network with a high bandwidth, perhaps one that uses Wi-Fi 6. A higher bandwidth will allow you to move larger quantities of data without encountering network congestion.

Network throughput, like bandwidth, is also a useful diagnostic tool. When experiencing poor performance on an internet device, you can’t immediately be sure whether this is a problem with the device or with the network it’s running on. However, if you measure throughput, you might notice that you have a low internet speed, confirming that a problem is arising from the network, not your laptop or smartphone.

Monitoring both bandwidth and throughput can provide useful information to help you increase internet speed and network performance.

What is the difference between throughput and bandwidth?

The difference between bandwidth and throughput comes down to what they are measuring. Throughput is a measurement of a network’s practical performance and speed, while a network’s bandwidth represents how much data you can theoretically move through the network at once.

Throughput is useful when you want to see how fast your network is currently running. Bandwidth is an important metric for assessing overall network capacity. People sometimes use the terms interchangeably, since both are useful concepts in networking, but they refer to different metrics.

As outlined in a previous analogy, bandwidth can be seen as the width of the road along which data travels. Network throughput, on the other hand, is the speed at which the data can move on that road and reach its destination. Tracking both bandwidth and throughput can give you a fuller picture of how your network is operating and the amount of data you can move through it at once.

How do you measure bandwidth and throughput? We’ll cover both metrics and the steps to measure them below.

How do you measure throughput?

Monitoring network throughput is a good place to start if you’re having internet problems. You can measure throughput in many different ways using network monitoring tools. Some operating systems have an in-built network performance monitor for testing network throughput, but you can also install third-party software for the same purpose.

Both Windows and macOS come with inbuilt services to measure network performance, but these focus more on device performance than overall network speed. A third-party tool can help. One of the simplest options is called iPerf3.

How do you measure bandwidth?

You can measure your internet bandwidth with a variety of online tools, though these won’t necessarily give you an exact number for your maximum bandwidth. To get an approximate figure for your maximum bandwidth, run multiple tests over several days to generate an average bandwidth.

To test the bandwidth available through a local area network (LAN), use network bandwidth monitoring software. Many third-party apps are available to test bandwidth. Just install one of these on a device connected to your LAN and run a test through the software’s interface, following the in-app instructions.

How do throughput and bandwidth affect network speed and performance?

The higher your bandwidth and throughput, the faster your network is going to move data and perform tasks.

If you have less network bandwidth — for example, if your internet service provider is engaging in bandwidth throttling — files will download and upload slowly. This can make watching online entertainment or playing games through the internet much more difficult. You can counteract targeted bandwidth throttling by using a VPN, though this only works if your network is being throttled based on your internet activity.

Likewise, low throughput means data takes longer to reach its destination. If your router is slow, for example, or if your device is positioned very far from your router, data packets arriving from the internet will take longer to reach your device.

Fundamentally, high network bandwidth and throughput will always mean faster internet speeds and better network performance.

Of course, throughput and bandwidth are just two of the metrics we can use to measure network speed and performance. Another important factor to consider is latency.

What is latency, and how does it affect network performance?

Latency represents the time a data packet takes to move from one place to another on a network. If you have high network latency, it means the packet is taking longer than optimal to reach its destination. Low latency, on the other hand, indicates faster speeds.

Latency is just another way of measuring and quantifying network speeds. To assess whether your network is performing poorly, you might start by checking the latency on the network using an online speed test site. If you have high latency, it could mean that your bandwidth is inadequate or your router needs to be replaced.

To lower your latency, consider moving your device closer to your router, as physical distance can have a major impact on data speeds. If you’re using a wireless network, your connection may be slower if you are in a different room from the router. You can also connect your device to your router using an Ethernet cable. An Ethernet link usually provides a faster and more stable online experience.

Latency isn’t the only factor to consider, however. Several other key network performance metrics should be tested, especially if you’re having ongoing networking problems.

Are there other key network performance metrics?

While knowing how much data you can move through your network and what speeds you can maintain is useful for avoiding network bottlenecks, other performance metrics should also be considered.

Packet loss

When data is sent through a network, it is first broken down into tiny packets of data. These travel individually and are reassembled on arrival at their destination. When a packet fails to reach its intended recipient, this is called a packet loss. Tracking packet loss as a metric is important because high packet loss could indicate that your network infrastructure is inadequate for the amount of data it’s handling.

If your network monitoring tool alerts you to high packet loss, it might be time to upgrade your network devices or increase your bandwidth.

Ping rate

Ping rate is another metric that describes latency on a network. In a ping test, you send a small data packet to a server. When the packet arrives, the server sends a packet back. The time this exchange takes is referred to as a ping rate. A high ping rate indicates a slow network.

Retransmission

When packet loss occurs, some transfer protocols will retransfer the packets. Measuring retransmission rates is another way to track packet loss. It’s always good to know how much data is being lost during transmission. If retransmission occurs regularly, this can cause the network’s overall data transfer rate to drop since packets have to be sent multiple times. To avoid poor network performance, quickly address potential causes of packet loss and retransmission.

While metrics like retransmission and packet loss are important if you’re trying to achieve optimal network performance, the first thing to check when problems arise is your overall network speed, as represented by throughput. If it’s unusually slow, this could be the result of targeted bandwidth throttling based on user activity. A VPN can protect you from bandwidth throttling if your ISP is targeting you because of specific online activity.

VPNs hide your online activity from internet service providers, meaning that you are less likely to be personally targeted with bandwidth throttling. With NordVPN, your overall privacy and network security will also be enhanced. NordVPN encrypts data in transit, hides your IP address, and lowers the risks of cyberattacks.