Hybrid CPUs are coming

Hybrid CPUs are coming
5 min read
20 September 2020

It wasn't long ago that the idea of putting several processors into one package seemed exotic, but with modern multi-core CPUs that integrated graphics, maybe it was only a matter of time before Intel and AMD added even more functionality to your computer's most important component, the CPU.

Both companies are working on hybrid CPU that could really shake up what the future of computing will look like, specifically for laptops and devices that depend heavily on good battery life. But what exactly is a hybrid CPU?

The basic idea is that it's a multi-core CPU where all the cores are not the same. Instead you get a mix of high power and low power cores, a paradigm that's already used in many Arm chips for smartphones called big.LITTLE. Hybrid CPUs are coming The advantage of this is many of the tasks we do on our laptops, such as working in a Word processor or browsing social media, don't necessarily use tons of computing power, but the processing cores which are designed to do a lot more, can still use a lot of electricity when they're doing those things, even if the system is throttling their clock speeds. So instead, a hybrid CPU takes advantage of cores that specifically you have the same capabilities as a traditional laptop processor core, but the major plus is that they use a lot less energy, but when your PC is doing something that needs some extra processing muscle, you still have those higher power cores for the heavy lifting.

Assigning tasks to the low power or the high power cores is the responsibility of a scheduler. A scheduler is typically built into the operating system and is responsible for deciding the order in which your computer will execute tasks. In a hybrid CPU, the hardware is specifically designed to coordinate with the operating system scheduler so that the CPU and Windows or whatever OS you are using, can work together to figure out what tasks makes the most sense to assign to each core. So a demanding foreground tasks like photo editing could get assigned to the big core, while background tasks will be delegated to the little cores, which are more power efficient, but I can hear you already, what about just putting Arm CPUs inside of laptops? Apple's doing it, so why doesn't everybody just follow suit?

Well, the big difference is that AMD and Intel's hybrid projects are still built around x86 architecture, the same one they've been using for decades, and the one that most Windows applications are written for. Apple has the luxury of being able to rewrite its own operating system and software to work well on its in-house designed Arm CPUs, but on Windows laptops, trying to translate x86 applications to run on Arm CPUs, results in significant performance loss.

In fact, Qualcomm, a major manufacturer of Arm chips, has tried to break into the Windows laptop market with Arm CPUs, but the slowdowns that result from the fact that Windows applications won't run natively on Arm has prevented Qualcomm from becoming a major player in the laptop processor market. But this doesn't mean that just because hybrid processes run on x86 architecture that they're perfect solutions. Scheduling for maximum efficiency presents a real engineering challenge, and because you're mixing different types of processor cores, code that might work on one type of core may not work on another. So chipmakers might be forced to remove support for certain instructions from one or more cores to ensure programs can run on both sets of cores without causing an error, as software typically assumes all cores support the same instructions, but despite those challenges, the technology does have promise.

Intel in particular has sunk a great deal of money into developing it. And there's already one laptop that features an Intel hybrid CPU code named Lakefield. We also know AMD has filed a patent for a similar technology though is unclear when we'll see hybrid CPUs from team red. But as for me, I just want something that'll last a long time, even if I misplace my laptop charger, which I've done once or twice. 

Alex 10K
Joined: 4 years ago
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Comments (1)
  1. Den W.

    They´re following the trend of hybrid cars: small, efficient electric motors for driving in cities, and large and (relatively) powerful but inefficient engines for occasional large trips.

    3 years ago ·
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