Working out CPU power

[jjohnthedon1]

So to figure out how powerful a CPU is 

would the equation

icp X clock speed X amount of cores 

be the right ? 

I understand that different programs are designed to run on different amounts of cores 

but want to no if this is a way to work out CPU performance rather than synthetic benches ? 

 

And should cache speed be considered ? 

[2FA]

If it is the same architecture, you can do that for single core performance. Multicore performance is too reliant on the programmer of the software so this method doesn't work. 

 

Different architectures don't work this way, eg. Bulldozer v. Haswell.

[jjohnthedon1]

7 minutes ago, DeadEyePsycho said:

If it is the same architecture, you can do that for single core performance. Multicore performance is too reliant on the programmer of the software so this method doesn't work. 

 

Different architectures don't work this way, eg. Bulldozer v. Haswell.

So if I wanted to compare single core performance between haswell and bulldozer 

would it be clock speed X ipc's ?

[Moonzy]

38 minutes ago, jjohnthedon1 said:

icp X clock speed X amount of cores

roughly... each instruction will require different instruction cycles

and each architecture process each instruction differently, will require different instruction cycles, so theres that

so you cant measure performance just by comparing them like this especially if they are of different architecture

 

26 minutes ago, jjohnthedon1 said:

So if I wanted to compare single core performance between haswell and bulldozer 

would it be clock speed X ipc's ?

no, best way is synthetic benchmarks tbh...

[jjohnthedon1]

20 minutes ago, Moonzy said:

roughly... each instruction will require different instruction cycles

and each architecture process each instruction differently, will require different instruction cycles, so theres that

so you cant measure performance just by comparing them like this especially if they are of different architecture

 

no, best way is synthetic benchmarks tbh...

Ok thanks

[Moonzy]

2 minutes ago, jjohnthedon1 said:

Ok thanks

also how effectively are you using the cores?

hyperthreading helps the core to be more effective

[2FA]

56 minutes ago, jjohnthedon1 said:

So if I wanted to compare single core performance between haswell and bulldozer 

would it be clock speed X ipc's ?

No, the design of Bulldozer's architecture is very different compared to Haswell. So much so that you could argue that the cores of Bulldozer aren't cores by definition. Fun fact is that definition of a core and Bulldozer is the center of class action lawsuit against AMD for lying about their architecture. It likely won't go anywhere though because the definition of a core is kind of vague.