Gamer Hardware: Should I focus on the CPU or the GPU?

 Intro

The most important parts of a gaming computer are undoubtedly the cpu and the gpu. The gpu processes the game's graphics, outputting everything you see in a game and the cpu processes the game's physics. To make a long story short, making a wrong choice with each of these will make your games unplayable or playable with lower than optimal settings.
  In this blog post though, I do not intend to mention the best cpus and gpus for different budgets (you can find this in one of the numerous reviews posted on major hardware review sites). Instead,I want to focus on how you should balance your budget between these two components in order to achieve optimal performance .

    The importance of the processor in modern gaming

   To begin with, most pc exclusive games use the cpu extensively.The most obvious example are  rts games.

The cpu has to handle the AI of the units and often calculate projectile  physics. Due to this,  rts games like the Total War series and Starcraft 2  benefit a lot from faster cpus and more cores.

  Game engines with complex physics engines(Frostbite,Cryengine) are also cpu dependant.Bad company 2(Frostbite) needs a quad core cpu to run without hiccuping at every explosion.Even Garry's mod with the seemingly light for today's standards Source engine gives my i5 750 clocked at 3.8ghz a hard time when lots of objects are spawned.

  Furthermore, since the launch of the major videogame consoles in 2005-2006 (xbox 360,ps3),an annoying trend has appeared in the pc gaming market.Due to the large profits in the console market, many developers have either abandoned the pc gaming market and design games exlusive to consoles leading to a decline in game variety and quality. In addition to this, many other developers design games for consoles and then port them badly to computer cpus, making them much more cpu demanding than they could have been with proper optimising(grand theft auto 4,fable 3,Call of Duty:Black Ops etc.).

  The last thing,I should mention is that the cpu used in a system must always be powerful enough to handle the graphic cards. If it isn't, it limits them, resulting in unexpectedly lower performance.This phenomenom is called bottlenecking.

Bad Company 2 with different cpus

Farcry 2-It can be maxed out by most modern gpus,so it shows cpu scaling well

 The gpu

  A few years ago, a super expensive graphics card could make a difference between playing a game at acceptable settings or not playing it at all (think of Crysis in 2007).   Nowadays,one of the most popular complaints between pc gamers is that their games do not use their gpus to their full potential (one of the effects of the aforementioned consolitis). My personal observations from my gaming experiences and tons of reviews I've read online, verify this. How does that concern the subject at hand,you may wonder...Well, because of this,most games that have been released until now,can be played at great visual settings and full hd resolutions at acceptable fps(<30) by budget cards like the AMD Radeon 6870 and the Nvidia Gtx 560,both currently priced below 200$. Exceptions to this are Crysis 2 with the latest DX11 patch and Metro 2033 as they are extremely demanding at max settings. Still,I don't think these two games justify spending 200$ more on gpus. 

Bad Company 2 performance fromGuru3d)

Crysis 2 performance with different gpus(from Guru3d)

  On the other hand, there is a small percentage of people who have more than one monitor.Because of the large resolutions of these setups, extreme amounts of gpu rendering power and video ram are a necessity. The same goes for people who are planning to setup stereo 3D setups as these double the amount of pixels to be rendered.

Performance drop from 3d vision

Eyefinity performance drop

                                                                  

   Conclusion:Balance is the key

  A  saying here in Greece  fits the situation very much.It goes like that:"Τα μεταξωτά βρακιά χρειάζονται και επιδέξιους κώλους",roughly in English: "Silk underwear require appropriate a**es". The best graphics card in sli will be held back by a sub-par cpu and the fastest cpu in the market won't help your gaming if your graphics card is not up to the job.
 Still,this doesn't answer the question of where you should focus your budget because cpus and gpus are priced differently.My take on this is simple:First think of the games you will be playing.If they rely mostly on the cpu (fsx,rts games,even minecraft),then you should obviously focus on the cpu.An i7 2600k and a 6850 will perform better at these games than an i3 2100 with a gtx 570.If they rely mostly on the gpu though (Crysis 2 DX11,Oblivion with  texture packs,Dragon Age 2) , then of course you should focus on the graphics card.For crossfire/sli ,though, a fast,possibly overclocked cpu is a necessity.If the budget doesn't fit it, forget about the whole concept as it will perform poorly.

  

  A note on the sources of this post:This post is comprised of my experience from the many forums I take part in and from my own experiences from my computer.For a more in-depth analysis of bottlenecks in games,don't hesitate to take a look at this useful article from Tom's Hardware.Furthermore,the charts are taken from this and this articles from Guru3d.com.


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