Originally Posted by rubicsphere
That's the thing though an FX-8350 at 4.5Ghz has more single core performance than older i7's especially one at 2.8Ghz
A core in i7 is of two threads, the good thing is even a single thread has been designed to use 90% of transistor area of that core, usually a game is designed to use Floating point capability of CPU to decode its data for GPU. Therefore a game which can utilize only one thread is going to use 90% power of a single core (or FPU) of an i7 CPU. So you can say game is really using about 2.8 GHz or 2.7 GHz frequency of that core.
In FX this is very different.
We have one module running at 4.5 GHz (this means the total transistor frequency of a module when combined is 4.5 GHz ), and a module consists of two cores, and the bad thing is here in comparison to i7 is that No Single core in a module can utilize all transistor area of that module. Only one core can utilize FPU at a Time and the other core can do only Integer calculation. So again, when Arma III runs on FX CPU, it is using only one side of a module which is actually a FPU side. I've read in some reviews the distribution of resources of a module into two cores is about 75% and 25%. Hence in this condition you are only utilizing about 75% of transistor switching frequency of a module when using FPU calculation, and leaving remaining frequency for Integer workload which btw is not being utilized by ARMA III.
So in very actually its not that i7 2.8 GHz beating a FX at 4.5 GHz in single thread, it should be happening like i7's one thread running at around 2.7 GHz beating FX's one thread running at around 3.0-3.4GHz.
Overall its the AMD's fault its performing inferior.Edited by sumitlian - 9/16/13 at 10:14am