Throughout this video we’re going to do
a desktop computer dissection using 3D animation. Kind of like a dissection lab in biology class,
but instead, we’ll journey through the inside of this computer and disassemble every piece
of hardware. We’ll then use a microscope and zoom in to give you a nanoscopic view
of the transistors and other structures inside. To make this video we disassembled all the
hardware inside a typical desktop computer, we desoldered and removed the components from
each of the printed circuit boards and took thousands of pictures. Then using these
pictures, we meticulously 3D modeled every single component from the computer case down
to the tiniest resistor. As a result, here’s all the hardware that we’ll explore throughout
this video. It kind of looks like a crime scene where someone viciously destroyed a
computer and arranged all the components, but anyways let’s dive right in.
We’ll begin this journey with the Central Processing Unit or CPU which is the brain
of the computer. On top we have the cover, called an integrated heat spreader, and inside
is a smaller metal package that holds the integrated circuit which is technically called
a die. This die is mounted on a printed circuit board that distributes the 1200 connection
points to landing pads that interface with the landing grid array on the motherboard.
The integrated circuit inside has a few different sections, but perhaps the most recognizable
are the 10 cores where programs and instructions are run. Each core is quite complicated,
so here’s a diagram laying out the different functional sections. There are dozens of
rather complicated elements in this diagram, and you can look forward to a series of videos
we’re currently planning which will explore computer architecture and how each of these
sections work. Let’s zoom into a nanoscopic view of the
integrated circuit so we can see individual transistors. These transistors are incredibly
small, only a few nanometers wide and in this die there are approximately 8 to 10 billion.
On top of the transistors are multiple layers of metal wires with vias rising vertically
between the layers. Together these transistors and wires create a multilayer labyrinth or
highway resulting in a computer that can execute billions of operations every second.
Let’s now zoom out and look at other sections of the CPU. To the side of each core is
the shared L3 memory cache and ring interconnect. On the far right is an integrated graphics
processor which functions as a less powerful GPU; in the top left is the memory controller
which sends data to and from the DRAM; and finally on the far left is the system agent
and platform I/O, which communicates with the Chipset on the motherboard and manages
the flow of data between many of the other components in your PC. So, with that in
mind, let’s move on and look at the motherboard. This motherboard is a massive, printed circuit
board with thousands of wires running inside and a variety of microchips, components,
sockets, ports, slots, headers and connectors soldered to it. Perhaps the single most
important and expensive component, aside from the bare PCB, is the Chipset, which is this
integrated circuit found underneath a heat sink down here and is connected directly to
the system agent section in the CPU. Here’s a diagram illustrating how the CPU and chipset
are connected to everything else. As seen here, the CPU connects directly to the DRAM,
one or two displays, the GPU, and perhaps a few SSDs plugged into the M2 slots. The
Chipset manages most everything else: data flowing through the ethernet or Wi-Fi, data
going to and from solid state drives and hard drives plugged into the SATA ports, some of
the PCIe slots, your keyboard and mouse, USB devices, and the audio sent to the speakers
or from the microphone. Just a quick note, computer hardware has evolved
immensely over the past 65 years and continues to evolve, so the details we show should be
thought of as a current day example PC and not as how all computers work.
Let’s move on and skip over the many different sockets and connectors throughout the motherboard
and focus on the voltage regulator module or VRM found near the CPU. These components
are used to drop the voltage coming from the power supply down to the 1.3 volts used by
the CPU. As a result of all the power flowing through these components and their 80 to 90
percent efficiency, heat sinks need to be placed on top.
While we’re on the topic of power, this CPU consumes power equivalent to approximately
16 LED bulbs, thus generating a considerable amount of heat which is taken away by the
CPU cooler. This particular cooler uses a pump to circulate liquid through these tubes
and into the radiator’s channels which transfers heat to the radiator fins. The fans then
help transfer the heat to the air and the cooled liquid returns to the pump via the
return loop. The pump is a brushless DC motor constructed from a PCB, a control chip
and a stator on the dry side, a barrier in the middle, and then the permanent magnet
rotor and impeller on the liquid side. There’s no mechanical connection between the rotor
and stator, thereby preventing any leaks of the cooling liquid.
Let’s move onto the power supply which distributes power throughout the computer. In here,
the main transformer reduces the voltage and bridges the isolation boundary between the
primary side high voltage and the secondary side lower voltages used throughout your computer.
Here’s the control PCB that ensures a stable output voltage and sends adjustment signals
to the switching power transistor on the primary side using opto-isolators. There are dozens
of other components used to filter the input voltage and generate various output voltages
which are then sent to all the different hardware in your computer. For example, an SSD consumes
just a few watts, and the connector uses these voltages, whereas your GPU can consume hundreds
of watts using these connectors and these voltages.
Next, we’ll explore the GPU, but before that, let’s take a step back and consider
the technology we’ve covered thus far. Alone, each of these components doesn’t
do much at all, but when united, they combine to form a powerful system. Similarly, this
video is a multidisciplinary combination of engineering, technology, art and animation
inspired by the Magic School Bus. We can’t emphasize enough how important it is to be
a multidisciplinary student. And to help you do that, the sponsor of this video is
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Let’s get back to dissecting this computer and move onto the graphics card and GPU which
is also the brain of the computer… well… actually this analogy doesn’t really work
very well but anyway… Opening the graphics card we see another PCB, with the GPU’s
integrated circuit in the center, VRAM chips all around, and the voltage regulator module
on the side. Above the IC is a heat sink with a fan to dissipate heat, and on the side
of the graphics card are HDMI and Display Ports, a PCIe Interface and then on the other
side is the input power connector. Let’s focus on the GPU integrated circuit
which, similar to the CPU, has more than a thousand solder pads that connect it to the
PCB. Opening the packaging we find the GPU die which is noticeably different from the
CPU. In here are approximately 11.8 billion transistors organized into 6 graphics processing
clusters, totaling 28 streaming multiprocessors. Each streaming multiprocessor is composed
of 128 cores, resulting in a total of 3,584 cores. Each core has sections for integer
and floating-point arithmetic, and sections for queueing in the operands and collecting
the results and is far simpler than a CPU core. Additionally, on the die is an L2
memory cache shared among all the graphics processing clusters, a set of memory controllers
that connect to the VRAM located around the processor, and a PCIe interface for connecting
to the CPU. When we zoom in to see a nanoscopic view of
the integrated circuit we find something very similar to what we saw in the CPU, with the
transistors on the bottom and a labyrinth of multiple layers of metal wires above.
All these structures are manufactured in multibillion dollar semiconductor fabrication plants or
fabs but that’s a topic for a whole different video, so let’s move on. GPUs and CPUs
are similar in many ways, however, GPUs have thousands of cores that are limited to basic
arithmetic, whereas CPUs have only a handful of cores that perform far more complicated
operations. Additionally, CPUs have branch prediction and deep pipelines that optimize
the execution of code. Here’s a quick example of what GPUs can do. Take this image
comprised of 16 million pixels each with RGB values for each pixel. A simple way to brighten
the image is to add 20 to each of these numbers. A CPU has 10 cores and thus performs arithmetic
10 numbers at a time whereas GPUs distribute the data to thousands of cores thus performing
magnitudes more parallel processing. Let’s close this graphics card and talk
briefly about the 3D model. Note that this is a slightly older model graphics card because
we buy most of our hardware as non-functioning parts from eBay, and then, as shown earlier,
we tear them down rather destructively in order to accurately model everything. Additionally,
sometimes components shown aren’t compatible, such as this motherboard that says DDR4, while
the DRAM is DDR5. That said, modeling and animating everything
to make it feel like you’re actually inside a computer took us around 500 hours and we
would greatly appreciate it if you could take a few seconds to hit that like button, subscribe
if you haven’t already, type up a quick comment below, and share this video with someone
who will enjoy it. Also, we have a Patreon and would appreciate any support. We’re
planning more videos on computer architecture and other related topics and can’t do it
without your help, so thank you for doing these 4 quick things. It helps a ton.
Let’s move on and look at the DRAM, Solid State Drives, and Hard Drives. We’re not
going to spend too long, because we have an entire series of videos on solid state drives,
and then separate videos covering DRAM, and Hard Drives. But quickly, the CPU communicates
directly with the DRAM through memory channels running inside the motherboard. Inside each
of these 8 DRAM chips is an integrated circuit composed of 32 memory banks each 8192 columns
wide by 65536 rows tall. The DRAM temporarily stores data using capacitors and transistors
called 1T1C memory cells in 2D arrays that look like this. Data can be accessed within
nanoseconds, however, among these 8 chips, only 16 Gigabytes of data can be temporarily
stored. Take a look at our 35-minute video on DRAM, but for now let’s move on
to SSDs which permanently store data in 3D arrays called 3D NAND. This array is 100
to 200 layers tall, 32 to 64 thousand columns wide and 32 to 64 thousand rows deep. Additionally,
within a single SSD chip such as this one, are multiple 3D NAND arrays stacked one on
top of the other. As a result, a single microchip can store terabytes of data, however
reading or writing data takes 50 or so microseconds, which is 3000 times slower than DRAM. Zooming
in on a single SSD memory cell we find a charge trap which stores different levels of charge
allowing for 3 bits of data to be more permanently saved. Looking at the NVMe and SATA SSD,
both have a few 3D NAND data storage chips, a DRAM chip for buffering and holding the
data mapping table and a controller chip. Let’s move on and dissect the hard disk
drive. Here we have a disk mounted to a spindle with a motor that rotates the disk
at thousands of rpm. A read write head moves across the disk in order to access a single
track out of half a million other data tracks. Let’s zoom in on the read write head.
The write head changes the direction of localized magnetic domains in a small layer on the disk
whereas the read head senses these changes in magnetic domains. This disk drive is
even slower than the SSD, taking a few milliseconds to access, thus resulting in slower read and
write times, but costing less per terabyte of storage.
Thus far we’ve covered all the hardware inside your computer. So, thanks for watching
this far, and as a bonus here’s what it looks like inside a computer mouse, with the
scroll wheel up top, the infrared light, image sensor, and multiple lenses down here and
the battery and processor in the middle. For computer mice we have separate dedicated
videos exploring the image sensor and scroll wheel with incredible details.
Additionally, here’s what it looks like inside a basic keyboard, with plastic traces
that carry electricity to each key and, when pressed, that key completes a circuit which
is sensed by the processor up here. That’s pretty much it for what it looks
like inside your computer. We believe the future will require a strong emphasis on engineering
education and we’re thankful to all our Patreon and YouTube Membership Sponsors for
supporting this dream. If you want to support us on YouTube Memberships, or Patreon, you
can find the links in the description. Also, thank you again to Brilliant for sponsoring
this video. This is Branch Education, and we create 3D
animations that dive deep into the technology that drives our modern world. Watch another
Branch video by clicking one of these cards or click here to subscribe. Thanks for watching
to the end!