When buying a new laptop or building a computer, the processor is one of the most important decisions. But there’s a lot of jargon, especially the core. For example, do you need a dual-core processor, quad-core, hexacore, octa-core or more?
Let’s cut through the jargon and figure out what it really means.
Dual-Core vs Quad-Core, Explained
There is always only one processor chip. That chip can have one, two, four, six, eight, ten, twelve or even sixteen cores. So if you get a “single core” CPU, it means that the processor chip has a single core. And a dual-core processor has two cores, a quad-core has four, a hexa-core has six, an octa-core has eight, and so on and so forth.
Currently, an 18-core processor is the best you can get in a consumer PC. I mean, you can buy the 64-core AMD Threadripper, which is available to consumers, but that’s more processing power than most regular consumers can think of using.
Each “core” is the part of the chip that performs processing tasks. Essentially, each core is a central processing unit (CPU).
This article deals with dual-core vs quad-core processors for computers, not smartphones. We have a separate post to understand the smartphone core.
You might think that more cores would make your processor faster overall, but this is not always the case. It’s a bit more complicated than that.
More cores are faster only when a program can divide its tasks among the cores. Not all programs are developed to split tasks between cores. More on this later.
The clock speed of each core is also an important factor in speed, as is the architecture. A newer dual-core CPU with a higher clock speed will often outperform an older quad-core CPU with a lower clock speed.
power consumption
More cores also lead to higher power consumption by the processor. When the processor is on, it supplies power to all cores at once, not just one.
Chip makers are trying to reduce power consumption and make processors more energy efficient. But as a general rule of thumb, a quad-core processor will draw more power from your laptop (and thus drain the battery faster).
more cores equals more heat
More factors than the core affect the heat generated by the processor. But again, as a general rule, more cores generate more heat.
Because of this extra heat, manufacturers need to add better heat sinks or other cooling solutions.
Are quad-core CPUs more expensive than dual-core?
More cores doesn’t always mean a higher price. As we said earlier, clock speed, architecture version and other considerations come into play.
But if all other factors are equal, more cores will fetch a higher price.
Software optimization for CPU cores
Here’s the dirty little secret the chip makers don’t want you to know. It’s not always about how many cores you’re running; It’s about what software you’re running on them.
Programs have to be specially developed to take advantage of multiple processors. In the past, “multi-threaded software” wasn’t as common, although with single-core CPUs nearly impossible to buy these days, the problem isn’t what it once was.
However, it is important to note that even though it is a multi-threaded program, it is also about what it is used for. For example, the Google Chrome web browser supports multiple processes, as does the video editing software Adobe Premiere Pro.
Adobe Premiere Pro assigns different cores to work on different aspects of your editing. Considering the multiple layers involved in video editing, this makes sense, as each core can work on a different task.
Similarly, Google Chrome instructs different cores to work on different tabs. But here lies the problem. Once you open a web page in a tab, it is usually static thereafter. No further processing work is required; The rest of the work is to store the page in RAM. This means that even though core can be used for background tabs, it is unnecessary.
This example from Google Chrome is an example of how even multi-threaded software may not give you a real-world performance boost.
double the cores is not double the speed
So assuming you have the right software and all your other hardware is the same. Would a quad-core processor be twice as fast as a dual-core processor then? No.
Increasing cores doesn’t solve the software problem of scaling. Scaling up to the cores is the theoretical ability of any software to assign the right tasks to the right cores, so each core is computing at its optimal speed. In reality this does not happen. In reality, tasks are divided sequentially (which is what most multi-threaded software does) or randomly.
For example, let’s say you have a quad-core processor (Core1, Core2, Core3, Core4). To complete a task you need to complete three tasks (T1, T2, T3), and you have five such tasks (A1, A2, A3, A4, A5).