So what are core ? Why are they so important ?

CPU CORES : SIMPLIFIED

The central processing unit (CPU) in your computer does the computational work — running programs, basically. But one single-core CPU can only perform one task at a time, which is where multiple CPUs, hyper-threading, and multi-core CPUs come into play.

Having more than a single CPU allows multiple programs to run at the same time, ensuring your computer stays responsive — especially while multitasking or performing computationally-demanding tasks like video encoding.

Multiple CPUs

Most computers only have a single CPU. That single CPU may have multiple cores or hyper-threading technology, which we’ll cover later — but it’s still only one physical CPU unit inserted into a single CPU socket on the motherboard.

Before hyper-threading and multi-core CPUs came around, people attempted to add additional processing power to computers by adding additional CPUs. This requires a motherboard with more than one CPU socket — multiple CPUs are inserted into different sockets. The motherboard also needs additional hardware to connect those CPU sockets to the RAM and other resources. There’s a lot of overhead here — there’s additional latency if the CPUs need to communicate with each other, systems with multiple CPU will consume more power,  and the motherboard needs more sockets and hardware.

Hyper-Threading Technology

Hyper-threading was Intel’s first attempt to bring parallel computation to consumer PCs. It debuted on desktop CPUs with the Pentium 4 HT back in 2002. The original Pentium 4 had just a single CPU core, so it could only do one thing at a time — but hyper-threading attempted to make up for that.

A single physical CPU core with hyper-threading appears as two logical CPUs to an operating system. The CPU is still a single CPU, so it’s “cheating” a bit — while the operating system sees two CPUs for each core, the actual CPU hardware only has a single set of execution resources for each core. The CPU pretends it has more cores than it does, and it uses its own logic to speed up program execution. Hyper-threading allows the two logical CPU cores to share physical execution resources. This can speed things up somewhat — if one virtual CPU is stalled and waiting, the other virtual CPU can borrow its execution resources. Hyper-threading can help speed your system up, but it’s nowhere near as good as having additional cores.

Multi-Core CPUs

Originally, CPUs had a single core. That meant the physical CPU had a single central processing unit on it. To increase performance, manufacturers add additional “cores,” or central processing units. A dual-core CPU has two central processing units, so it appears to the operating system as two CPUs. A different process can be using each core at the same time. This speeds up your system, because your computer can do multiple things at once.

Unlike hyper-threading, there are no tricks here — a dual-core CPU literally has two central processing units on the CPU chip. A quad-core CPU has four central processing units, an octa-core CPU has eight central processing units, and so on.

The more CPUs or cores a computer has, the more things it can do at once. This helps improve performance across everything you do — even if you’re just doing one thing at a time, the computer needs to perform background tasks.