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 Brilliant.org. Brilliant is a multidisciplinary
online education platform which teaches a ton of different topics in hands-on interactive
ways. Here are two courses from different disciplines that you might think were entirely
unrelated. However, when combined they provide the foundational basis for a cutting-edge
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Don’t worry, you won’t be learning from boring textbooks, but rather Brilliant uses
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some of the lessons for free and, if you like them, which we’re sure you will, you can
sign up for an annual subscription. We personally are currently working through their lessons
on quantum circuits and algorithms for a future video that dives into Quantum Computers.
Brilliant is offering a free 30-day trial with access to all of their thousands of lessons,
and to the viewers of this channel, Brilliant is offering 20% off an annual subscription
to the first 200 people who sign up. Just go to brilliant.org/brancheducation. The
link is in the description below. 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!