Processr's role in a gaming PC

I have observed that processors hardly have any impact on a game's performance, provided the graphics card is really good. I mean.....I've noticed people with a weak processor but a powerful graphics card playing games with almost all the eye candy, whereas those with a very good processor but weak graphics card struglle to play those games. So is it true that the processor's impact on game perfromance is very limited? In that case, is there really a need to invest in in a powerful processor, or is it better to buy a moderate processor and use the saved money to increase the budget for the graphics card?

P.S. I'm saying this purely with respect to gaming, because I know there are several instaces where the processor's impact is really high.

I have observed that processors hardly have any impact on a game's performance, provided the graphics card is really good. I mean.....I've noticed people with a weak processor but a powerful graphics card playing games with almost all the eye candy, whereas those with a very good processor but weak graphics card struglle to play those games. So is it true that the processor's impact on game perfromance is very limited? In that case, is there really a need to invest in in a powerful processor, or is it better to buy a moderate processor and use the saved money to increase the budget for the graphics card?

P.S. I'm saying this purely with respect to gaming, because I know there are several instaces where the processor's impact is really high.

funkyzoom

I think it all depends on the game.

Processors set up the entire scene to be rendered. They can be a massive bottleneck to 3D performance. 

I believe (it's been awhile since I actually did this) they are what do the majority of the geometry calculations and calculate shadows (as they are based off the geometry) because the CPU is what defines the camera. The GPU handles the shading which is far more resource intensive.

Bascially it works like this for each frame.

1. Large art assets are loaded into the vRAM (textures mostly) 
2. Game logic and gameworld are stored in system RAM
3. CPU runs all of the game logic cacluations and defines the place for the camera in the environemtn
4. CPU calculates all of the geometry and determines things like lighting, shadows and anything where logic needs to be applied
5. CPU sends scene to the GPU where the various stages of the rendering pipeline do their work on the imagine
6. GPU then outputs the completed image

The CPU can actually set up frames faster than the GPU can render thus you can have a buffer of completed frames (frame run-ahead) ready for the GPU. 

Back when Supreme Commander first came out, i had to upgrade my CPU because my slow cpu was unable to handle all those unit/particle calculations. I think it matters when there are many objects on the screen that need to have its movements/actions calculated. Not sure on that though.

The CPU is providing a bridge between the software environment (game engine) and other hardware connected to your motherboard, including but not limited to the sound, networking, storage and other peripherals. You will notice the most activity when you are loading the game through your operating system. Most CPUs today have integrated graphics processing, such as the Intel i7 with the Intel HD 4000 graphics. Integrated graphics are done within the CPU and your system RAM alone.

Dedicated GPUs are designed specifically for buffering graphics to a display device, and they do this by rapidly altering memory blocks and performing complex calculations specifically for the production of graphics. Dedicated GPUs and their respective GDDR RAM can process and refresh their memory much faster than standard CPUs and DDR RAM are capable of.

I think (could be wrong) a good general rule of thumb is that the processor is more important for RTS games, while the GPU is more important for FPS. Everything else kind of falls in between. I know GTA 4 performs like crap if you don't have a quad core processor.PurpleMan5000

All depends really.

BF3 takes a huge hit on the cpu....but then so does EQ2.

Seems to me that it just depends on how the game is made.

I have observed that processors hardly have any impact on a game's performance, provided the graphics card is really good. I mean.....I've noticed people with a weak processor but a powerful graphics card playing games with almost all the eye candy, whereas those with a very good processor but weak graphics card struglle to play those games. So is it true that the processor's impact on game perfromance is very limited? In that case, is there really a need to invest in in a powerful processor, or is it better to buy a moderate processor and use the saved money to increase the budget for the graphics card?

P.S. I'm saying this purely with respect to gaming, because I know there are several instaces where the processor's impact is really high.

funkyzoom

In 90% of the cases this is true. A mid-range processor and 500$ GPU will be like 80% more efficient than an I7 with a 250$ gpu. But you should also look at the cpu requirements for gaming, for example, once dualcore support is dropped then it´s dropped, you will have to buy a multicore processor no matter what. 

But I also heard that strategy and simulation games are more CPU dependant due to the fact that a lof calculations are made in those games in the background, not seen by the player.

FPS and adventures, in contrast, visually heavy, are totally  gpu dependant.

The thing is CPU evolution went so ahead of gaming by now, so even a mid range cpu will last you easily 4 years.

Video card = graphics 

Cpu = Calculations

Depends what games you play.

If you play more simulation-style games (e.g. Arma, Flight Simulator, rFactor, ect.), stategy games (e.g. Total War, StarCraft, ect.) and large-scale/open world games with lots of going on (e.g. GTA, TES, ect.), you will need a beefy CPU as a lot of calculations will take place on it.

But if you play more arcade-style games (e.g. "corridor shooters", arcade racing, beat-em-up, ect.), you won't need a powerful CPU because there's not much calculations going on and might as well invest more into the graphics card.

Best idea would be to get a "balanced" system, imo, so no component will be "bottlenecking" another one and you'll be able to enjoy the biggest range of games.

 Like mentioned it really does depend on the game. Some games are mostly and completely 'GPU Bound' and yet some rely heavily on CPU... they can be heavily 'CPU Bound'.

Also the vast majority of games that came out more than a year ago or there abouts can only utilise 2 core's on a CPU, but games are increasingly being released that can utilise more and more cores. 

Its why you can see a good increase in FPS on benchmarks in a certain game with a CPU like the i5 for example compared to lets say a 4-Core Piledriver chip, with the rest of the system, like the memory and graphics card being exactly the same!

Video card = graphics 

Cpu = Calculations

khanabyss25

I was gonna say
Video Card = Prettiness
CPU = Math 

The role depends heavily on the game. A game like BF3 doesn't use that much CPU power but depends heavily on my graphics card, while a game like PlanetSide 2 is bottle necking pretty bad on my processor.nightcall14

[QUOTE="nightcall14"]The role depends heavily on the game. A game like BF3 doesn't use that much CPU power but depends heavily on my graphics card, while a game like PlanetSide 2 is bottle necking pretty bad on my processor.C_Rule

Yeah I was gonna say....multiplayer fps went up like mad when I upgraded my cpu.