Something about CPU's I don't understand

[Natsoup]

I've been looking into how computer parts work - like what's inside, why some parts are faster - but I've come across a roadblock in my thought process.

 

Why are some CPU's way slower than others even though they have a faster clockspeed and the same or more cores? I always thought something like this:

Cores * Clockspeed = performance

but clearly there's much more to it than that!

 

Can someone explain the more complicating factors in CPU power?

[NumLock21]

architecture of the cpu

[Ashiella]

2 minutes ago, Natsoup said:

I've been looking into how computer parts work - like what's inside, why some parts are faster - but I've come across a roadblock in my thought process.

 

Why are some CPU's way slower than others even though they have a faster clockspeed and the same or more cores? I always thought something like this:

Cores * Clockspeed = performance

but clearly there's much more to it than that!

 

Can someone explain the more complicating factors in CPU power?

I used to know all about that, then I forgot... Rip me, rip brain.

[Djole123]

IPC is the word you're looking for. IPC stands for instructions per clock, and that is how much calculations can it do with every "tick".

 

So why does the FX 9590 get beaten by even a mid tier Intel quad core? Because Intel SKUs have a much higher IPC, so they can do more at lower clocks.

[Ashiella]

1 minute ago, NumLock21 said:

architecture of the cpu

The IPC didn't matter on the architecture.

[TheRandomness]

IPC, or instructions per clock(cycle), can also affect a CPU's performance quite drastically. For example, a CPU with low IPC but high clocks (such as the FX 9590) will be beaten by a lower clocked CPU with higher IPC, hence Intel's i5s from 3 generations ago beating the 9590.

1 minute ago, Ashiella said:

The IPC didn't matter on the architecture.

Yes, yes it does.

[Guest]

4 minutes ago, Natsoup said:

I've been looking into how computer parts work - like what's inside, why some parts are faster - but I've come across a roadblock in my thought process.

 

Why are some CPU's way slower than others even though they have a faster clockspeed and the same or more cores? I always thought something like this:

Cores * Clockspeed = performance

but clearly there's much more to it than that!

 

Can someone explain the more complicating factors in CPU power?

Imagine 2 cars. One a truck with 8 wheels and same engine. And then a racing car with 4 wheels and same engine. Which will go faster?

[Natsoup]

4 minutes ago, deXxterlab97 said:

Imagine 2 cars. One a truck with 8 wheels and same engine. And then a racing car with 4 wheels and same engine. Which will go faster?

"Answering a question with another question means you probably don't know the answer"

-me, just now

[Ashiella]

11 minutes ago, TheRandomness said:

IPC, or instructions per clock(cycle), can also affect a CPU's performance quite drastically. For example, a CPU with low IPC but high clocks (such as the FX 9590) will be beaten by a lower clocked CPU with higher IPC, hence Intel's i5s from 3 generations ago beating the 9590.

Yes, yes it does.

I've seen some older arcs have better IPC than newer.

[TheRandomness]

1 minute ago, Ashiella said:

I've seen some older arcs have better IPC than newer.

You just proved yourself wrong..?

13 minutes ago, Ashiella said:

The IPC didn't matter on the architecture.

 

[NumLock21]

2 minutes ago, Ashiella said:

The IPC didn't matter on the architecture.

Talking about IPC will make it even more confusing, since IPC is not something that's actually physical. How do you make a cpu with faster IPC, where does it come from, and how does it work? It all comes down to the architecture of that cpu.

Much like you have 2 buildings, both are build using the same process, a foundation, concrete, and steel beams. One of them can go up to 200 floors and yet the other ones tops out at 50 floors. How comes both buildings using the same exact process, can come out with different results? Same with CPU, it's the way on how they designed it (cpu architecture) makes the difference.

[Ashiella]

1 minute ago, TheRandomness said:

You just proved yourself wrong..?

 

I meant that if the arch is better doesn't mean the IPC is.