What is Data Transfer Rate?

Data Transfer Rate (DTR) can be defined as the ratio of the total amount of digital data transferred between two points in some defined period of time. Where the two points can be two network components say two computers or data can be transferred between a thumb drive and a hard drive. Data transfer rate is actually a measure of the speed at which network components can exchange data(send or receive). It is measured in either bits per second or bytes per second. For practical purposes, it is measured in Megabits per second or Megabytes per second. But you have usually seen KBps (Kilobyte per second) while uploading or downloading something. Japan has shown the highest data transfer rate of 14 terabits per second using only a single optical fiber cable.

Data Transfer Rate(DTR) = Total amount of Digital data transmitted/Total time taken

Some data transfer rate units are:

1 Kbps = 2¹⁰bps = 1024 bps

1 Mbps = 2²⁰bps = 1024 Kbps

1 Gbps = 2³⁰bps = 1024 Mbps

1 Tbps = 2⁴⁰bps = 1024 Gbps

Importance of data transfer rate in the computer network:

Data transfer rate is of utmost importance in today's world because of the following reasons:

• It has a direct effect on one's business especially if it is some kind of online service because then you must have a high data transfer rate to provide services without any interruption.
• Data transfer rate is also important in performing some complex tasks like online streaming, having a video call, or any work which is life and is of high priority.
• Data transfer rate is also used in the assessment of different devices and technologies.
• Data transfer rate gives an insight into the performance of a system and network, so it is useful for making improvements.

Factors affecting data transfer rate

There are several factors that affect the data transfer rate, some of them are:

1.  Network Congestion: Network Congestion can be understood as a situation that may arise if the user sends data at a greater rate than that permissible by network resources. When the network resources reaches their maximum capacity then it affects the data transfer rate.

Following problems arise due to network congestion :

• Packet Loss: Packets are lost due to network congestion as after the expiry of the time to live or having no more hop limit the data packet automatically drops.
• Increase in Delay: Due to packet loss no acknowledgment will receive at the sender side so after a timeout period sender will send new data packets so which will increase the delay in communication.
• Network termination: Network will face connection issues as sessions will be dropped because due to network congestion too many packets are lost. One will get session timeout messages on the screen or page that is taking too long to respond to messages.

 2. Condition of Client or Server: It means the client or server should be in a good condition meeting all the criteria for making a better network. It should have all the necessary hardware along with the latest software. The data transfer rate will surely be affected if the minimum processor, RAM, and other components are not fulfilling the defined minimum requirement criteria. Suppose for achieving a data transfer rate of X KBps we need a minimum of 4 GB ram and an octacore processor if these criteria are not fulfilled then the data transfer rate will get affected.

3. Latency: Latency is defined as the amount of time needed by the network to transfer a data packet from source to destination. If latency is affected by one or more parameters then in turn it will affect the data transfer rate. There is an inter-dependent relationship between latency and data transfer rate which depends on the protocols which are used to carry data.

Some of the factors which affect latency are:

• Path Length traveled by the packet from source to destination.
• Effectiveness and reliability of network devices.
• Count of devices which are being hoped in reaching to the destination.
• Latency also depends on the performance of individual devices used in data transfer from source to destination.

4. Transmission Media: The data transfer rate is different for different media available like if we are using an optical fiber cable and a twisted pair cable then the data transfer rate will obviously be different. For example, USB 1.0 has a data transfer rate of 12 Mbps while USB 2.0 has a rate of 480 Mbps. Similarly, USB 3.0 and 3.1 have a data transfer rate of 5 GB per second and 10 GB per second respectively.

Calculating Data Transfer Rate

Suppose your internet provider has advertised to give you a speed of 80 Mbps (Megabits per second) and you have a file of say 80 MB then how much time will it take?

Let's calculate, we know that there are 8 bits in 1 byte so speed should be divided by 8 as our file is in bytes not in bits.

So speed will be 80/8 = 10 MBps (Megabytes per second)

now 80 MB file will be transferred in 80/10 = 8 seconds.

This is how we calculate the downloading speed and time of files.

Now there are two terms :

• Downloading Speed: Downloading Speed tells us how fast data/files can be transmitted from server to your computer.
• Uploading Speed: Uploading Speed tells us how fast we can upload data/files to a server from our system by using the internet.

There are a number of tools available online to measure downloading and uploading speed some of them are broadband performance and speedtest. One can also test hardware by using software like HDTach and CrystalDiskMark.

Sample Questions 

Question 1: What is the data transfer rate if 50 Megabyte is transferred in 4 minutes?

Solution:

Step 1: Convert the time into seconds

4 minutes = 4 × 60 seconds

= 240 seconds

Step 2: Calculate data transfer rate using formula 

Data Transfer Rate = Total amount of Digital data transmitted/Total time taken

D = A/T 

= 50/240

= 0.208 Megabyte per second

Here the data transfer rate is in Megabyte per second so convert it to Megabit per second

Step 3: Converting MBps to Mbps

0.208×8 = 1.664 Megabits per second

We multiplied by 8 as there are 8 bits in one byte.

Question 2: How much data will be transferred in 1 hour at a rate of 100 bits per second?

Solution:

Step 1: Convert the time into seconds

1 hour = 60 minutes = 60×60 seconds

= 3600 seconds

Step 2: Using formula  D = A/T 

Amount of data = Data transfer rate × time

= 100 × 3600

= 360000 bits 

Step 3: Convert it to bytes

= 360000/8

= 45000 bytes

You can also convert it kilobytes by dividing it by 1024.

Question 3: How much time will be taken to transfer 50 GB data at a rate of 4 MBps ? 

Solution:

Step 1: Convert 50 GB data to MB as data transfer rate is in MBps

50 GB = 50  × 1024 MB

= 51200 MB

Step 2: Using formula  D = A/T 

time = 51200/4

= 12800 seconds

Step 3: Converting it to hours 

12800 seconds = 12800/3600 hours

= 3.55 hours

Question 4: What is the data transfer rate in KBps if 100 Megabyte is transferred in 2 minutes?

Solution:

Step 1: Convert the time into seconds

2 minutes = 2 × 60 seconds

= 120 seconds

Step 2: Calculate data transfer rate using formula

Data Transfer Rate = Total amount of Digital data transmitted/Total time taken

D = A/T

= 100/120

= 0.83 Megabyte per second

Here the data transfer rate is in Megabyte per second so convert it Kilobyte per second

Step 3: Converting MBps to KBps

0.83 × 1024 = 849.92 KBps

Question 5: How much time will be taken in minutes to transfer 25 GB data at a rate of 10 MBps ? 

Solution:

Step 1: Convert 25 GB data to MB as data transfer rate is in MBps

25 GB = 25  × 1024 MB

= 25600 MB

Step 2: Using formula  D = A/T

time = 25600/10

= 2560 seconds

Step 3: Converting it to minutes

2560 seconds = 2560/60 minutes

= 42.66 minutes