What makes a CPU faster?

What makes a CPU faster?

Clock speed, number of cores and cache size, with the run times worked out.

Transcript

Clock speed is how many cycles the CPU completes each second, measured in gigahertz. A three gigahertz CPU completes three billion cycles every second.

A higher clock speed means more instructions each second, so the same job finishes sooner. But it also makes more heat.

A core is a complete processing unit. A dual core CPU has two, a quad core has four, so more instructions can run at the same time.

But extra cores only help when the work can be shared. A job that must go one step at a time gets no faster.

Cache is a small, very fast memory inside the CPU. It keeps the data and instructions used most often. When the data is in the cache, the CPU does not wait for the much slower R A M.

A faster clock, more cores, a bigger cache. Three ways to get more done, every second.

More in this series

1:21

Inside the CPU

The control unit, ALU and registers, the Von Neumann architecture and the three buses.

cpuhardware

1:36

The fetch-decode-execute cycle

Follow one instruction through the PC, MAR, MDR, CIR and ACC registers, then run a small program.

cpuregistershardware

1:00

Embedded systems

A computer built into a device for one job: examples, and how it differs from a general-purpose computer.

embeddedhardware

1:45

Input devices

Keyboards, mice, touch screens, microphones, cameras, scanners and barcode / QR readers.

inputhardware

1:41

Output devices

Screens, projectors, printers, 3D printers and speakers: what each one does.

outputhardware

1:06

Sensors and actuators

A control loop: a sensor measures, the processor decides, an actuator acts. A thermostat shown step by step.

sensorsactuatorshardware

1:29

Primary storage: RAM, ROM and virtual memory

Volatile RAM, non-volatile ROM with the boot program, and what virtual memory does when RAM is full.

ramrommemoryhardware

1:30

Secondary storage

Magnetic, optical and solid-state storage, plus cloud storage.

storagehardware

1:34

Network hardware: NIC, MAC, IP and routers

What a network interface card, MAC address, IP address (IPv4 and IPv6) and router each do.

networkipmacrouterhardware

5:10

Unit 3 quiz

Ten questions with a think-time countdown and explained answers.

quizrevision