Why cpu?

[42thgamer]

Hello

I am new to to pc world and I have a question. I always here that a gpu is more impotent then a cpu for gaming. I also heard that a gpu is also better at number crushing, but iI am not sure a bout that.

So my question is why don't you get a cheap cpu and a much better gpu? I know it does influence it but my question is why. 

I also heard that some games are very cpu intensive, why is this?

Sorry for the probably stupid questions!

[yathis]

CPU needs to be 4 cores 4 threads or 4 cores 8 threads and really really fast, the faster the better in gaming.

i5 or i7

 

You can bottle neck the GPU with the CPU.

Open World games are very CPU intensive because it needs to load all the time.

[42thgamer]

2 minutes ago, yathis said:

CPU needs to be 4 cores 4 threads or 4 cores 8 threads and really really fast, the faster the better in gaming.

i5 or i7

 

You can bottle neck the GPU with the CPU.

Why does the performance of the gpu depends on the cpu

[Lurick]

CPUs are like swiss army knives, they can do a lot of things and do them pretty well.

A GPU is like a finely crafted butcher knife, it can do a couple of things very very well but not much else.

A fast CPU is needed to forward instructions onto the GPU in a certain amount of time and also process other things the GPU cannot.

[42thgamer]

2 minutes ago, Lurick said:

CPUs are like swiss army knives, they can do a lot of things and do them pretty well.

A GPU is like a finely crafted butcher knife, it can do a couple of things very very well but not much else.

A fast CPU is needed to forward instructions onto the GPU in a certain amount of time and also process other things the GPU cannot.

Thanks! That was the answer I wanted! Thank you so much!

[djmoney]

2 things here

 

Games are often not optimized for multi core/thread so a 4ghz I5 will often perform the same in games as a 4ghz i7 as the game is not taking advantage of the hyper threading.

 

Games that are CPU intensive are games that have to generate random environments like city sims, and GTA.  In GTA the people and cars are just spawned opposed to something like Mario where all of the people and environment are planned out ahead of time.  

 

As for number crunching this tends to be on the folding and mining stuff I don't know much about that.  

 

With all of that I wouldn't use a super old cheap CPU with something like a 1080 ti the CPU will slow down the card.  Its more like get an high end i5 oppose to a cheap enthusiast i7 you will see better performance out of that.    

[42thgamer]

2 minutes ago, djmoney said:

2 things here

 

Games are often not optimized for multi core/thread so a 4ghz I5 will often perform the same in games as a 4ghz i7 as the game is not taking advantage of the hyper threading.

 

Games that are CPU intensive are games that have to generate random environments like city sims, and GTA.  In GTA the people and cars are just spawned opposed to something like Mario where all of the people and environment are planned out ahead of time.  

 

As for number crunching this tends to be on the folding and mining stuff I don't know much about that.  

 

With all of that I wouldn't use a super old cheap CPU with something like a 1080 ti the CPU will slow down the card.  Its more like get an high end i5 oppose to a cheap enthusiast i7 you will see better performance out of that.    

Thank you!

[djmoney]

6 minutes ago, 42thgamer said:

Why does the performance of the gpu depends on the cpu

the CPU is still the crossing guard of the system.  If it is really slow then instructions to the GPU get held up in traffic.  

[42thgamer]

2 minutes ago, djmoney said:

the CPU is still the crossing guard of the system.  If it is really slow then instructions to the GPU get held up in traffic.  

Yes you answered most of my questions! I might look into how gpu work (more or less).

[bowrilla]

The CPU has to handle all the information and send it to the GPU. Major difference is: CPUs have very few very powerful computation cores while GPUs have many cores that individually are weaker than a CPU core. 

Since there aren't that many tasks in RL that can run entirely parallel with each other at some point it doesn't make any difference how many cores you might add. Current games run pretty well on 4 core 4 thread CPUs, often a bit better on 4 core 8 thread ones but above that … no real advantage if you throw more cores at your game. Different story though with software like audio/video/photo editing, CAD or stuff like that. GPUs are perfect for repetitive smaller tasks. When the CPU sends data to your GPU all there is are some coordinates for the geometry and some color values in form of textures. Your GPU has to do the math and calculate a projection of this 3d scene on your 2d screen – or in easier words: it has to do a lot of math to determine how those 2d pixels on your screen should look like.

 

If you have a very very weak CPU the whole game mechanics (like movement of character models, AI decisions), networking, sound etc will eat up all the little power. Keep in mind: 60FPS mean that your scene has to be recalculated including all those other elements 60 times per second. At the same time, the CPU has to send a bulk of data to the GPU for it to calculate what to display.

That's basically why you need to balance your system: if the CPU is too slow, the power of your GPU don't give you anything since it doesn't get enough data and a slow GPU means that the CPU has to wait for the GPU to finally render the image so it can get to the next frame.

[42thgamer]

30 minutes ago, bowrilla said:

The CPU has to handle all the information and send it to the GPU. Major difference is: CPUs have very few very powerful computation cores while GPUs have many cores that individually are weaker than a CPU core. 

Since there aren't that many tasks in RL that can run entirely parallel with each other at some point it doesn't make any difference how many cores you might add. Current games run pretty well on 4 core 4 thread CPUs, often a bit better on 4 core 8 thread ones but above that … no real advantage if you throw more cores at your game. Different story though with software like audio/video/photo editing, CAD or stuff like that. GPUs are perfect for repetitive smaller tasks. When the CPU sends data to your GPU all there is are some coordinates for the geometry and some color values in form of textures. Your GPU has to do the math and calculate a projection of this 3d scene on your 2d screen – or in easier words: it has to do a lot of math to determine how those 2d pixels on your screen should look like.

 

If you have a very very weak CPU the whole game mechanics (like movement of character models, AI decisions), networking, sound etc will eat up all the little power. Keep in mind: 60FPS mean that your scene has to be recalculated including all those other elements 60 times per second. At the same time, the CPU has to send a bulk of data to the GPU for it to calculate what to display.

That's basically why you need to balance your system: if the CPU is too slow, the power of your GPU don't give you anything since it doesn't get enough data and a slow GPU means that the CPU has to wait for the GPU to finally render the image so it can get to the next frame.

Thank you verry much! Real good explanation! I learn a little bit everyday! Today thanks to you! 

[Ordinarily_Greater]

2 hours ago, yathis said:

CPU needs to be 4 cores 4 threads or 4 cores 8 threads and really really fast, the faster the better in gaming.

i5 or i7

 

You can bottle neck the GPU with the CPU.

Open World games are very CPU intensive because it needs to load all the time.

Open world? Like need for speed most wanted?

[42thgamer]

8 hours ago, Ordinarily_Greater said:

Open world? Like need for speed most wanted?

are you stalking me? 

just kidding I kind of like you