Intel's i5 vs AMD FX-8150

To put it simply you cannot rely just specs alone since the CPU architectures are different between AMD and Intel which determines how well / quick they can execute instructions. In a way it's kinda like using a dating service, you simply cannot tell whether or not you absolutely want to be in a long term relationship with a guy / girl simply based on his / her profile.

While the specs tells you how fast the CPU's clock speed is, you cannot tell how well / efficiently it can execute instructions; known as IPC (instructions per clock or cycle). It is both the IPC and clockspeed that more or less determines how powerful the CPU actually is in this simplistic explanation. Intel has designed their CPUs to have very IPC, while AMD's IPC are not quite so high. Therefore, a lower clocked Intel CPU can outperform a higher clocked AMD CPU, depending on exactly which CPUs you are comparing. Why doesn't AMD simply make high IPC CPUs like Intel? Easier said than done. It requires a lot of money, research, and time to do so.

The fact is each individual Intel CPU core is more powerful than each individual AMD CPU core. Therefore, an Intel CPU core running at only 2.0GHz, is either just as powerful or more powerful than an AMD CPU core running at 2.5GHz. However, we are no longer in the era of single core CPUs anymore, we are in the age of CPUs having multiple cores. AMD's strategy to compensate for it's lower IPC core is to increase the clockspeed and increase the number of cores.

Explaining clockspeed is simple. Let's just say an Intel CPU can execute 100 instructions every 100MHz while an AMD CPU can only execute 80 instructions every 100MHz. That means an Intel CPU running at 2.0GHz can execute 2,000 instructions every second. However, since the AMD CPU can only execute 80 instructions every 100MHz, that means the AMD must be clocked at a higher speed in order to execute a total of 2,000 instructions every second which is 2.5GHz; 80 x 25 (multiples of 100MHz). Therefore, AMD CPUs need to be clocked higher in order to equal an Intel CPU.

Multiple cores complicates matters. First, the program / game must be designed to take advantage of multiple cores to gain any performance advantages. If the program / game is not designed to use multiple cores, then only one core will be used. I have read several posts where people stated that most online MMO games only one core. Whether that is true or not I do not know. I believe Sims 3 is an example of a modern game that only uses one core. Along with higher clock speeds AMD attempts to compete against Intel by adding more cores to their CPUs. It's actually less expensive and quicker compared to designing a CPU architecture with very high IPC. The problem lies in the fact that the vast majority of games released only use 2 cores. There are some games that can make use of 4 core, and there are very few games that can make use of more than 4 cores.

The issue also lies in how well the game can make use of the multiple cores. Simply having multiple cores and the capability using them does not automatically mean that performance is higher. For example, 8350rocks mentioned a game that he was playing where all 8 cores of the FX-8350 was being utilized. I found a CPU performance benchmark of the game. I can't remember which game, but if 8350rocks mentions it, then I can look for that performance chart again. Anywaste, included in that CPU performance chart was the 6 core FX-6300 which provided the same exact performance as the 8 core FX-8350 (well there might have been 1 FPS difference). So a 6 core and 8 core CPU provides the same performance. Since the load is being spread across all 8 cores in the FX-8350, I will assume the load is also spread across all 6 cores in the FX-6300.

So what does that mean? Since both CPUs provide the same performance, that means the game is designed inefficiently. Each core in the FX-8350 does less work compared to the FX-6300 where each core does more work, but the output (performance is still the same). If the game was designed efficiently, then the FX-8350 would provide better performance than the FX-6300. I will also add that the Intel quad core i5-3470 outperformed both FX-8350 and FX-6300 in that particular game.