01 - Computer Basics | 04. Units of Measure In Computing

Question 1

What is the smallest unit of data for computers?

Answer 1

A bit, the binary digit.

Question 2

What are the values a bit can have?

Answer 2

This unit of data can only have one of two values: 0 or 1, usually to represent if an electronic signal is off or on.

Question 3

A grouping of 8 bits is also called what?

Answer 3

A byte

Question 4

A kilobyte is what abbreviation?

Answer 4

Kilobyte (kB)

Question 5

How many bytes is a kB and what is an example size?

Answer 5

1000 Bytes and an example size is a typical email (~2kB)

Question 6

A megabyte is what abbreviation?

Answer 6

Megabyte (MB)

Question 7

How many bytes is a MB and what is an example size?

Answer 7

1000^2 Bytes and an example size is a novel (~1.5MB) or 1 song (~5MB)

Question 8

A gigabyte is what abbreviation?

Answer 8

Gigabyte (GB)

Question 9

How many bytes is a GB and what is an example size?

Answer 9

1000^3 Bytes and an example size is a 1080p movie (5GB)

Question 10

A terabyte is what abbreviation?

Answer 10

Terabyte (TB)

Question 11

How many bytes is a TB and what is an example size?

Answer 11

1000^4 Bytes and an example size is entire major libraries

Question 12

A petabyte is what abbreviation?

Answer 12

Petabyte (PB)

Question 13

How many bytes is a PB and what is an example size?

Answer 13

1000^5 Bytes and an example size is all the data held by a major tech company.

Question 14

T/F | Modern drives are faster for storage performance?

Answer 14

TRUE.
If hard drives only had a speed of 1 megabyte per second (MBps), then the example song above would take 5 seconds to load before playing! No user would consider that acceptable!

Luckily, modern drives are much faster than that. The storage of most devices today are solid state drives. For portable devices such as phones, they are usually able to read files at about 1500 MBps and write new files at 500 MBps. Desktop devices are able to reach read and write speeds of over 5000 MBps!

Question 15

What is Throughput for data?

Answer 15

Throughput is the total amount of data that can be transferred during a given amount of time.

Question 16

What is Latency for data?

Answer 16

Latency, the amount of delay before that transfer of data begins.

Question 17

Why is knowing latency helpful?

Answer 17

This is helpful when many small files need to be transferred and the data seeking and accessing processes needs to be repeated many times.

Question 18

What is SSD?

Answer 18

Solid-State Drives

Question 19

What is ISP?

Answer 19

Internet Service Provider

Question 20

Data speed not only applies to storage data but also to what?

Answer 20

These types of data speeds don’t apply to just storage devices. It is true for any appliance that transfers data.

Internet bandwidth and latency are measured the same way. However, instead of representing the speed of a specific device, measures of Internet devices consist of the entire “pipe” that attempts to bring the data to a device.

Everything from the speed of the server providing the data, the miles of cables connecting it to an Internet service provider (ISP), and all of the similar connections until it reaches the desired device make up this measure. Most importantly, these speeds are decided by the slowest device along the entire chain. Even if a consumer owns the fastest routers and computers, if the server is an ancient turtle connected with shoestring to the Internet, the entire connection will be slow.

Question 21

What is the next step for all of this data that is brought to the computer?

Answer 21

It needs to be processed by the central processing unit, CPU.

Question 22

T/F | Each CPU has a clock speed for determining how quickly it can do computations.

Answer 22

TRUE

Question 23

What are the common speeds of a CPU?

Answer 23

Each CPU has a clock speed for determining how quickly it can do computations. This is commonly about 3.5GHz or 3.5 billion operations per second, and will likely stay around that number for the foreseeable future to physical limitation in the durability of silicon.

Question 24

What is a more important measure than CPU?

Answer 24

A more important measure going forward is the number of cores a CPU contains. Each core within a CPU can do one computation at a time. Therefore a CPU with four cores can simultaneously do four times as many computations as a CPU with one core. So need to make a computationally heavy task four times faster? Just get a processor with four times as many cores! For well-threaded programs it’s really that simple.

Question 25

What is GPU?

Answer 25

Graphical Processing Unit

Question 26

How are CPU and GPU similar and different?

Answer 26

Graphical processing units (GPUs) are similarly measured to CPUs, as they are both devices focused on computations. However, with the GPU’s different goal of computing graphics comes different implementations. They tend to have many more computational cores (up to 80!), but with much slower clock speeds (around 2GHz).

Question 27

Energy is measured in?

Answer 27

Watts

Question 28

Why is it important to measure electricity usage?

Answer 28

More powerful devices tend to use more energy.

This is an important measure because over time the cost of electricity can eclipse the cost of the actual device. So much so that it is common for servers to be completely replaced by newer models not because of speed improvements, but because of improvements in power consumption.

Power consumption has other effects as well. All of the energy taken in by a device is dissipated as heat, so more powerful devices will typically need complex cooling solutions to best maintain performance.

Question 29

T/F | Throughput is the total amount of data that can be transferred in a given amount of time.

Answer 29

TRUE

Question 30

T/F | Latency is the amount of delay before that transfer of data begins.

Answer 30

TRUE

Question 31

T/F | The smallest unit of data is the byte

Answer 31

FALSE

The smallest unit of data is the bit

Question 32

T/F | The performance of any data transfer, be it long-term storage devices, short-term RAM, or Internet devices is measured in the throughput and latency of this data.

Answer 32

TRUE

Question 33

T/F | Both CPUs and GPUs have similar measures for computation performance. Each is made up of cores that can do one operation at a time, and these cores have set clock speeds that determine how often they can perform these operations.

Answer 33

TRUE

Question 34

T/F | The energy devices use is measured in watts. The greater the wattage, the greater the amount of heat the device creates. Electricity costs can be a substantial part of the cost over the lifetime of the device.

Answer 34

TRUE