Hi and welcome to another in the Arm “What Is”  program series. In each episode, we dive into a  
Hi and welcome to another in the Arm “What Is”  program series. In each episode, we dive into a  

tech topic to give you insight and perspective  into some of today’s hottest design trends.  
tech topic to give you insight and perspective  into some of today’s hottest design trends.  

I’m Brian Fuller, editor-in-chief at  Arm and today we’re going to find out  
I’m Brian Fuller, editor-in-chief at  Arm and today we’re going to find out  

what is an SoC? Or to spell  it out, a system-on-chip?
what is an SoC? Or to spell  it out, a system-on-chip?

And to help us with that, I want to introduce  Richard Grisenthwaite, who is senior vice  
And to help us with that, I want to introduce  Richard Grisenthwaite, who is senior vice  

president, chief architecture and Fellow at  Arm. When he’s not helping us understand what  
president, chief architecture and Fellow at  Arm. When he’s not helping us understand what  

is an SoC, he enjoys hiking the West Highland  Way in Scotland, which took him seven days.
is an SoC, he enjoys hiking the West Highland  Way in Scotland, which took him seven days.

Welcome Richard, let’s dive right in!
Welcome Richard, let’s dive right in!

What is an SoC?
What is an SoC?

I think you said it yourself at the start there  Brian. An SoC is a System-on-Chip. It was term  
I think you said it yourself at the start there  Brian. An SoC is a System-on-Chip. It was term  

that came into currency when the amount of stuff  you can integrate onto a single piece of silicon  
that came into currency when the amount of stuff  you can integrate onto a single piece of silicon  

got to the point that you didn’t need to put  series of discrete chips onto a board. And this  
got to the point that you didn’t need to put  series of discrete chips onto a board. And this  

really started on the smaller end of things  into microcontrollers space where relatively  
really started on the smaller end of things  into microcontrollers space where relatively  

simple processor and were able to put memory in  some peripherals around it onto a single piece  
simple processor and were able to put memory in  some peripherals around it onto a single piece  

of silicon. And as Moore’s Law has continued  to give us more transistors, we’re able to  
of silicon. And as Moore’s Law has continued  to give us more transistors, we’re able to  

integrate more things into a piece of silicon.  So bigger and bigger systems are capable of  
integrate more things into a piece of silicon.  So bigger and bigger systems are capable of  

being built as the entire system on SoC rather  than a big board with your GPU separate or  
being built as the entire system on SoC rather  than a big board with your GPU separate or  

memory controller separate, it all  becomes on every single piece of SoC.  
memory controller separate, it all  becomes on every single piece of SoC.  

We saw this in particular in the case of Arm,  we saw the mobile space being big users of SoCs  
We saw this in particular in the case of Arm,  we saw the mobile space being big users of SoCs  

and we’ve seen more and more functionality come  onto that as our phones become more and more  
and we’ve seen more and more functionality come  onto that as our phones become more and more  

capable with the whole smartphone revolution.  And now for more, even bigger infrastructure  
capable with the whole smartphone revolution.  And now for more, even bigger infrastructure  

computers such as Neoverse N1, which is going  into things like Graviton G2 From AWS. Those  
computers such as Neoverse N1, which is going  into things like Graviton G2 From AWS. Those  

systems are using SoCs rather than a  collection of discrete components on a board.
systems are using SoCs rather than a  collection of discrete components on a board.

You mentioned this growing functionality  that design teams are putting onto SoCs.  
You mentioned this growing functionality  that design teams are putting onto SoCs.  

Is there any limit to that functionality  or to put it in another way, is there more  
Is there any limit to that functionality  or to put it in another way, is there more  

interesting functionality that is  coming in the next couple of years?
interesting functionality that is  coming in the next couple of years?

I think it is just a question of increasing  integration as the sizes of transistors keep  
I think it is just a question of increasing  integration as the sizes of transistors keep  

on getting smaller as we go down to five and three  nanometers right about now, we see that continuing  
on getting smaller as we go down to five and three  nanometers right about now, we see that continuing  

on for a bit more then you’re able cram more and  more functionality onto that. We’re already seeing  
on for a bit more then you’re able cram more and  more functionality onto that. We’re already seeing  

an order of a hundred CPUs now on a single SoC,  which was an incomprehensible amount if you go  
an order of a hundred CPUs now on a single SoC,  which was an incomprehensible amount if you go  

back 20 years ago. Nobody could have imagined  being able to put anything like that level of  
back 20 years ago. Nobody could have imagined  being able to put anything like that level of  

functionality on there. So it really comes  down to the size of transistors as to limits  
functionality on there. So it really comes  down to the size of transistors as to limits  

and we’re now talking about very, very big  systems that will fit onto a single SoC.
and we’re now talking about very, very big  systems that will fit onto a single SoC.

What are some of the design considerations that  
What are some of the design considerations that  

would prompt the design team to choose an  SoC versus say buying an off-the-shelf chip?
would prompt the design team to choose an  SoC versus say buying an off-the-shelf chip?

Well, I think part of it is the financial model  here. Clearly, the design and fabrication of an  
Well, I think part of it is the financial model  here. Clearly, the design and fabrication of an  

SoC is an expensive thing to do because you got  to create masks and run wafers and do all of that.  
SoC is an expensive thing to do because you got  to create masks and run wafers and do all of that.  

But once you’ve spent that upfront cost,  then the cost of the end product can be  
But once you’ve spent that upfront cost,  then the cost of the end product can be  

a lot cheaper per unit than assembling a  list of different components and it can be  
a lot cheaper per unit than assembling a  list of different components and it can be  

completely customized to what you want. It’s  really not so much a design consideration,  
completely customized to what you want. It’s  really not so much a design consideration,  

it’s just pure economics. If you expect a large  run of your design, you want to be very specific  
it’s just pure economics. If you expect a large  run of your design, you want to be very specific  

to what you are doing, you can justify the  expense, the upfront NRE of building an SoC.  
to what you are doing, you can justify the  expense, the upfront NRE of building an SoC.  

Then it’s the right direction to go in because  you get exactly what you want and you’re able to  
Then it’s the right direction to go in because  you get exactly what you want and you’re able to  

have precisely that functionality at a lower cost  per unit once you’ve amortized that initial cost.
have precisely that functionality at a lower cost  per unit once you’ve amortized that initial cost.

Are SoCs used in a limited number of  applications or are they more broadly applicable?
Are SoCs used in a limited number of  applications or are they more broadly applicable?

Well, I think, kind of the story I was telling at  the start of this is what we’ve seen is initially  
Well, I think, kind of the story I was telling at  the start of this is what we’ve seen is initially  

if we went back twenty years ago, people would  have said, “Oh SoCs, they’re only useable for  
if we went back twenty years ago, people would  have said, “Oh SoCs, they’re only useable for  

relatively small, simple computers.” Imagine the  mobile phone before we had smartphones when they  
relatively small, simple computers.” Imagine the  mobile phone before we had smartphones when they  

were relatively simple computing devices. No  one would imagine putting an entire server onto  
were relatively simple computing devices. No  one would imagine putting an entire server onto  

an SoC at that point because it really didn’t  make sense in terms the amount of integration,  
an SoC at that point because it really didn’t  make sense in terms the amount of integration,  

we were able to achieve. What has happened is as  we’ve been able to achieve more integration onto  
we were able to achieve. What has happened is as  we’ve been able to achieve more integration onto  

a single chip and as we get also 3D effects where  you’re able to put multiple chiplets together onto  
a single chip and as we get also 3D effects where  you’re able to put multiple chiplets together onto  

a single package, then you end up  being able to pretty much solve  
a single package, then you end up  being able to pretty much solve  

every problem. This is why even though the big  infrastructure solutions such as the Graviton G2  
every problem. This is why even though the big  infrastructure solutions such as the Graviton G2  

are moving into the SoC solution. In many ways,  this is just where all computing is going to go  
are moving into the SoC solution. In many ways,  this is just where all computing is going to go  

is they are going to be made out of SoCs based  around Arm. And that’s actually a big part of  
is they are going to be made out of SoCs based  around Arm. And that’s actually a big part of  

Arm’s advantages by being a component supplier  to people who want to build SoCs. They’re able  
Arm’s advantages by being a component supplier  to people who want to build SoCs. They’re able  

to build precisely the SoC they want. So we see  this as a really important market going forward.
to build precisely the SoC they want. So we see  this as a really important market going forward.

Well, thank you Richard! That was  a fantastic explanation of SoCs!  
Well, thank you Richard! That was  a fantastic explanation of SoCs!  

Now, check out all our other “What Is” episodes  here and be sure to subscribe to this channel  
Now, check out all our other “What Is” episodes  here and be sure to subscribe to this channel  

because we’ll be adding more as the  year progresses. Thanks for listening!
because we’ll be adding more as the  year progresses. Thanks for listening!