Cores & HyperThreading

Assalamualaikum and Hello everyone.Today I want to share simple explanation about cores and hyperthreading

• These days, most CPUs you’ll come across are dual core, quad core, or even octo-core. 

• I’ll explain exactly what a core is, dual core, quad core, and hyperthreading and how this all impacts your real-world computer usage

Each CPU “core” is actually a separate central processing unit, which is the part of the CPU that actually does the work. 

For example, a dual-core chip may look like a single CPU chip, but it actually has two physical central processing units on the chip

• Additional central processing units allow a computer to do multiple things at once. If you’ve ever used a single-core CPU and made the upgrade to a dual-core CPU, you should have noticed a significant difference in how responsive your computer is.

• Whether you’re doing multiple things at once or not, your computer is often doing system tasks in the background and you can benefit from additional cores to keep the operating system responsive. 

CPUs have a clock speed – CPU clock speed, or clock rate, is measured in Hertz — generally in gigahertz, or GHz. A CPU's clock speed rate is a measure of how many clock cycles a CPU can perform per second (think of it as how fast the CPU does work)

• For example, Intel’s Core i5-3330 processor has a clock speed of 3 GHz and is a quad-core processor, which means it has four cores. All four cores in this Intel i5 processor are each running at 3 GHz.[4*3=12Ghz]

Doubling The Cores Doesn’t Double The Speed

Many computer programs are single-threaded, which means that their work can’t be divided across multiple CPUs. They must each run on a single CPU. This means that doubling the cores won’t double their performance.

If you have a single-threaded application running on a 3 GHz quad-core CPU, that application will run at 3 GHz — not 12 GHz. It will use one core and the other three cores will sit idle, waiting for other tasks to perform.

More cores help if you’re looking to do more at once or if you have a multithreaded application that can take advantage of them.

 For example, if you’re running several virtual machines(ubuntu), extracting files, and doing other CPU-demanding things on your computer, an octo-core CPU may be able to keep up while even a quad-core CPU may stumble under such load.

Phrases like “dual core,” “quad core,” and “octo core” all just refer to the number of cores a CPU has:

Dual Core: Two cores.

Quad Core: Four cores.

Hexa Core: Six cores.

Octo Core: Eight cores.

Deca Core: Ten cores.

Intel CPUs use a technology referred to as “hyper-threading technology.” With hyper-threading, each physical core presents itself to the system as two logical cores.

•  In the screenshot above, I'm not using an quad-core CPU – I'm using a dual-core CPU with hyper-threading.

This improves performance to some degree, but a dual-core CPU with hyper-threading is nowhere near as good as an quad-core CPU