Fastest Microcontroller (MCU) vs Cheapest Microprocessor (MPU)
Most people think microcontrollers are simple, cheap, and slow… and microprocessors are complex, expensive, and fast.
In this video I’m flipping that upside down. Because I’m comparing a two-dollar Linux chip against a twenty-dollar microcontroller that’s literally twice as fast.
And the moment you see them side by side, everything people assume about these two categories starts to fall apart.
And here’s the weirdest part: Why is the microcontroller faster… and why is it more expensive?
We’ll get to that, but first there’s one critical difference between a microcontroller and a microprocessor that I need to tell you about, because it explains everything.
When people hear “microcontroller,” they usually picture a little chip with some flash, some RAM, a bunch of peripherals, and your firmware running directly on the hardware.
Power comes on, a tiny boot ROM runs, it jumps straight into your code, and that’s it.
No operating system. No virtual memory. No processes. Just raw execution.
A microprocessor is built for something completely different. It’s built to run an operating system like Linux.
That means external or high-density RAM, a more complex boot flow, and most importantly, an MMU, a Memory Management Unit.
And the MMU is really the dividing line.
If the core has an MMU, it can support virtual memory, process isolation, and everything a modern OS depends on.
If it doesn’t, you’re in bare-metal territory or maybe running a small real-time operating system.
So in the real world, a microcontroller gives you instant boot, deterministic timing, and tight control over everything happening on the chip. Nothing gets between you and the hardware.
A microprocessor gives you Linux, drivers, file systems, networking, and the ability to run multiple applications, but you pay for that with complexity, higher power, and timing that’s never fully predictable.
That’s the real dividing line. Not clock speed. Not price. The memory architecture and the type of software the chip is designed to run.
So let’s start with the Allwinner F1C100S, because this chip is just fascinating.
It’s built around an old ARM9 core from the early-2000s, a 32-bit architecture, not modern by today’s standards, but still totally usable.
The core runs at 533 megahertz, which is honestly impressive for a two-dollar part.
But the magic isn’t the clock speed. It’s the fact that it has an MMU and thirty-two megabytes of embedded DDR1 memory inside the package.
And that memory integration is what makes this cheap chip feasible.
If you had to route external DDR, deal with length matching, impedance control, and all the usual DDR headaches, nobody would be building a two-dollar Linux board.
But because the RAM is packaged with the processor, the layout becomes ridiculously simple. Suddenly you’ve got a tiny Linux-capable microprocessor you can drop onto a straightforward PCB without advanced routing rules.
That’s why you find this Allwinner microprocessor in cheap handhelds, kid toys, e-ink gadgets, little media players, anything where cost is everything and “runs Linux” gives you a big head start.
It runs a minimal Linux system, but you can still build perfectly usable little interfaces with it. You get USB 2.0, SD card support, an LCD controller, audio interfaces, and enough horsepower for menus, audio playback, and simple GUIs.
And because it runs Linux, you get access to a ton of existing software that would be painful to recreate from scratch on a bare-metal microcontroller.
Now let’s switch to the opposite end of the embedded world: the NXP i.MX RT1170.
This thing is technically a microcontroller, but in raw real-time performance it absolutely outmuscles a lot of low-end Cortex-A processors.
The main core is a one-gigahertz Cortex-M7.
Yes, one Gigahertz, and for a microcontroller that’s pretty ridiculous.
It also includes a four-hundred-megahertz Cortex-M4 for handling other tasks in parallel.
This NXP microcontroller is around twenty dollars for singles, and it approaches ten dollars in high-volume orders.
But even though it’s faster than the Allwinner Linux chip, it cannot run Linux. Not a real version of Linux.
Yes, there are scaled down versions of Linux it could technical run, but you lose memory protection, process isolation, and basically all the things that make Linux valuable to begin with.
So in practice, nobody uses it that way.
This microcontroller is built for something completely different: extremely demanding real-time workloads with very predictable timing.
It has two megabytes of on-chip SRAM plus tightly-coupled memory regions for each core, so the critical code can run with single-cycle latency.
You can attach external memory if you really want to, but the entire memory system is designed around consistent access times and high execution speed, not juggling multiple processes under an operating system.
That’s why you find this NXP microcontroller in industrial automation, robotics, motor control, instrumentation, audio processing, and advanced user interfaces where timing matters more than anything else.
There’s no scheduler pausing your control loop. No virtual memory creating random stalls. No kernel waking up to do housekeeping at the worst possible time.
If you say, “Run this interrupt every 20 milliseconds,” it runs every 20 milliseconds, forever.
So why is the microcontroller faster than the microprocessor? And why is the microcontroller the more expensive one?
You’d think the Linux chip would be the pricey one. Part of the answer is process technology.
The NXP microcontroller is fabbed on a more advanced node with tighter tolerances. That costs more. It’s also a bigger die with more on-chip memory and more peripherals.
But it’s also a completely different design philosophy.
Microcontrollers are optimized for raw execution speed and deterministic behavior.
They’re built to run tight loops at very high speed with predictable timing. So vendors squeeze every bit of performance out of them.
Microprocessors like the Allwinner part spend silicon on the MMU, on caches tuned for general-purpose workloads, on memory controllers for high-density RAM, and on peripheral blocks that expect Linux drivers to manage them.
Meanwhile, the NXP microcontroller skips the MMU, uses a simpler memory hierarchy, and focuses its silicon on compute performance, internal SRAM, and predictable bus structures.
Memory is another area where the split becomes obvious.
The Allwinner microprocessor has thirty-two megabytes of on-package DDR1. Super impressive at this price.
But once Linux boots, a good chunk of that is already spoken for. Between the kernel, background services, the filesystem, and your application, that memory goes fast.
It’s enough for simple UIs and light workloads, but you’re always working within pretty tight limits.
The NXP microcontroller lives in a totally different world. It’s all about fast internal SRAM with extremely low latency.
There’s no kernel eating cycles. No background tasks you didn’t ask for. And your firmware owns the entire system.
You control every byte and every cycle exactly how you want.
If you compare the Allwinner Linux chip and the NXP microcontroller in real-time workloads, the microcontroller absolutely destroys it.
Even though the Linux chip “runs Linux” and sounds more capable, the raw cycle-to-cycle throughput of the microcontroller is in a totally different league.
If you’re reading sensors, running control loops, or processing audio in real time, the microcontroller wins by a huge margin.
But if you want a GUI, media playback, a web server, or higher-level software, the Linux chip wins instantly, not because it’s faster, but because Linux brings a whole software ecosystem along with it.
Now let’s talk power for a moment.
The Allwinner Linux chip always has something running in the background, kernel threads, schedulers, timers, even when it looks idle.
That means higher baseline power. For anything plugged in, that’s fine.
But for long-life battery-powered products, that idle overhead starts to matter.
The NXP microcontroller on the other hand can drop into very low-power modes and wake up instantly with precise timing.
It’s a much better fit when you need both high performance and long battery life, something Linux really struggles with.
If you need help developing and launching a new electronic product, then check out my Hardware Academy.
And, if you found this video helpful then check out this video where I review some of the cheapest microcontrollers you can buy today.
