- This heatsink right here, pointless.
Four Ram slots, you only need two of them.
And why is there a PCI express slot that has SLI?
No one uses it.
Why the heck does everybody want all of this?
It's because nobody actually knows what motherboards are
and how they work.
So here it is,
to the best of our ability, how motherboards work.
So buckle up nerds, Linus is on vacation
and we're not holding back.
Just like I can't hold it back this segue to our sponsor,
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- Computer power supplies output 12 volts.
If you apply 12 volts to a CPU
it looks something like this.
Suboptimal, for sure.
(chuckles) Suboptimal for sure.
To avoid the magic smoke,
we need to take that 12 volts
and step it down to something more like 1.2 volts.
And this is exactly the job of voltage regulation modules
the VRMs that overClockers talk about so much.
The basic circuit consists of two MOSFETs
which in this situation are basically just fancy switches,
an inductor and a diode.
This first switch closes which then charges this inductor
converting the electricity into a magnetic field.
The voltage of the CPU gets
depends on how long the switch is closed
but the instant it is opened, the voltage to the CPU
begins to drop kinda like a drain.
So this is where that diode here is very important.
If both switches are open while the inductor is charged
it's magnetic field will collapse and pop goes your CPU
but the diode is highly inefficient.
So it's important to get the second switch closed as soon
as possible to avoid creating any unnecessary heat.
If you're paying attention
you might have noticed a problem here though.
Although the voltage will be bouncing
around what the CPU is asking for.
There are a lot of spikes, not great for stability
and there are two ways to remove this.
The first is to just increase how fast the MOSFET switches
on motherboards.
This is normally done at about 300,000 times per second
but even then the voltage can fluctuate more
than the CPU wants.
And it isn't practical to try
switching a whole lot faster than that.
Every single time the MOSFET switches on or off
it generates a bit of heat
and above about 150 degrees Celsius.
The MOSFET's gonna die.
So if we want cleaner power, we don't need faster MOSFETs,
we need more of them.
The circuit we have here represents a single phase sun.
Another term that overclockers love to use so much.
So by adding another phase, we can roughly
double how clean our power is with the benefits
of additional phases, scaling, roughly linearly.
From there, the number of phases
in your motherboard is normally shown
as a number like eight plus two, which means eight phases
for the CPU and two dedicated for the RAM.
Let me put this away.
Multiple phases also have another benefit.
Say you're a CPU requires a hundred amps to run
with a single phase.
All 100 amps would have to go directly
through those components.
But with two phases, only 50 amps to go through each phase
meaning lower rated and thus cheaper components can be used.
You might be tempted to think then,
well more phases equals more better,
which is true to a point.
However, as you add more phases
controlling them can get more difficult, which translates
into the VRM as being less able to respond
to changes in voltage.
Like everything then there are trade-offs
between having less phases with higher quality components
or more phases with lower quality components.
This does create a rather odd situation though.
High-end motherboards normally have the most phases
and the highest efficiency components
which means the VRM temperatures should be really low
but these motherboards also have the best VRM heat sinks.
Why purely to look cool.
Mid range boards might actually need good VRM cooling
but for anything other than extreme overclocking
the high-end board would probably be fine
with no VRM heat sinks at all.
It's similar to how you'd be fine without a shirt
from LTD store.com, but definitely look cooler with one.
- Now that the CPU has power
how does it talk to the rest of the system?
This copper wire represents how far an electric
signal can travel in a nanosecond falls.
At 5,000 megahertz your Ram can send data
every 0.2 nanoseconds in that amount
of time and electric signal can travel.
This far.
So then this
is physically impossible.
Ram makers have lied to you, although on your Ram stick
in the bios and in windows, your Ram will say it's running
at 5,000 megahertz or whatever.
In reality, it's completing
5,000 mega "transfers" per second.
What's the difference?
Well, since it's DDR or a double data rate Ram
transfers are done on both the beginning
and the end of each individual Hertz.
This means the sticks are actually running
at 2,500 megahertz, which is why
if you've ever looked in CPU Z, the Ram shows
up as half of what everything else claims it is.
Depending on what you want to do with your motherboard
knowing how the CPU and the Ram connect can be important.
Like have you ever wondered why the manual always
says to put the Ram
in the second and the fourth slots on your motherboard?
For this example, we'll be looking
at a CPU with dual Ram channels.
This is the most common configuration for consumer CPU's
but the same basic principles apply
to workstations or server processors with more channels.
The absolute best case scenario
for a dual channel CPU is to simply have two ram slots.
PCB traces go directly from the controller
to the Ram stick with nothing else in the way.
This is why Asus top tier gaming boards
only have dual slots.
And also why some ITX motherboards
like this one can punch way above
their weight class when overclocking Ram.
Moving onto other boards with four Ram slots,
here you have two main options
T topology and Daisy chaining.
T typology is when the traces to each Ram stick
on a channel are the same length.
Which can be great for running all four slots
at relatively high speeds.
But if pure speed is what you're
after then Daisy chaining is the way to go
with a Daisy chain motherboard, the traces basically just go
to one slot and then continue onto the next one.
This can cause the speeds to be lower.
When all four slots are used, the timing differences
between the two sticks has to be figured out
by the controller, but it also means with only two sticks
you can run them at nearly the same speed
as if there are only two slots.
Now it is important to use the correct slots though.
If an electric signal goes through a wire
and the wire suddenly ends with nothing connected
to it like this, the signal can reflect back creating noise
in the circuit.
By putting the Ram sticks and slots two and four
the traces and at the Ram stick, reducing noise
in the circuit and allowing for higher speeds.
So basically before you buy Ram ,
check if your motherboard has Daisy chain
or T topology since it determines
if you should get two higher capacity sticks
or four lower capacity ones with higher capacity
dims getting cheaper and cheaper, it now would make sense
for most gaming motherboards to only have two
Ram slots optimized to go as fast as possible.
Our contact at ASUS agreed
but said way too many people will complain
that they can't upgrade their memory in the future.
Even if statistically very few people actually will do that.
But even without typologies and slots, like
if you had the CPU right next to the Ram
and used gold traces or whatever for the perfect signal
there would still be something else holding you back,
the memory controller on the CPU.
Everyone has accepted at this point,
there's a Silicon lottery
and some CPU's will naturally be able to clock higher
at lower voltages, but the same applies
to the memory controller on the CPU.
Your luck in the Silicon lottery can sometimes
have the biggest effect on how fast your Ram runs.
- The CPU and Ram are now working
but we still need to be able to connect things
like the GPU, storage, and peripherals.
In the past this will be done through the chip set
with the North bridge taking care of PCIE and memory
will a Southbridge handle IO storage, audio USB
you know, on modern motherboards though, the memory
and some PCIE lanes are connected directly to the CPU.
Well, chip set handles everything else
which simplifies the layout and allows for lower latencies.
Losing a whole chip is big, but what's even more
shocking is just how fast PCIE has become
with PCIE 4.0 a one-lane slot can do
up to two gigabytes per second.
And a 16 lane slot is able to transfer a staggering 32
gigabytes. Second, that's close
to the speeds of DDR four Ram.
How, how the heck can they pull this off?
Simple, very expensive PCBs previously was possible
for lower end motherboards heavily like four or so layers.
But now in order to get PCI 4.0 levels of signal quality
eight to 12 layer PCBs are basically a requirement.
Given every two layers can come with a 20 to
30% cost increase for the PCB, the insane prices
of modern motherboards start to make a bit more sense.
Even if the majority of users will struggle to
saturate a PCI 3.0 connection, let alone 4.0
so you might have noticed a bit of a theme here.
One of the most difficult parts
of designing a motherboard isn't
creating the best possible product
but carefully balancing the actual value
and perceived value like this motherboard right
here supports SLI has massive VRM heat sinks.
It has four Dems
because those are things that people expect.
It probably would be better for the majority of users.
If there were just two ram slots
closer to the CPU, one PCIE connector, and you know
the price of this one down here was turned
into better traces and okay.
Okay. The VRM heat sink, it looks pretty cool.
And I wouldn't want to give it up
but at least I know that that's a trade off that I'm making.
And hopefully in the future
we can be more open to crazy motherboard designs
that either deliver higher performance or lower cost.
Huge, thanks to build soil for creating the videos used
as a reference for the VRM portion of this video.
I've got those link below
if you want to get even more in-depth than we did here.
And also thanks to JJ from ASUS for offering some insight
that only a motherboard expert can.
Also let us know down in the comments,
if you guys want to see more "turbo nerd" edition videos
and make sure to hit like this video is only able to go
down a couple of rabbit holes
and there are so many more here.
There are also so many more high quality segues
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If you like this video, maybe check out our recent video
on the semiconductor shortage that is making GPUS nearly
impossible to buy for a reasonable price.
At least it won't help you buy a GPU
but at least it lets you go down that rabbit hole.