Bottlenecked performance theory

[BenF]

Hello,

I have a question about bottlenecked hardware and how it relates to game performance. I will pose it in a hypothetical situation; here goes:


You have three systems playing the same game at the same resolution (lets say 1680x1050) all on "Low" in-game graphics settings. Each system runs the game at 60fps due to bottlenecked hardware.

System 1 is bottlenecked by its graphics card. The CPU, RAM and all other components are infinitely fast by comparison.

System 2 is bottlenecked by its CPU. The graphics card, RAM and all other components are infinitely fast by comparison.

System 3 is bottlenecked by its RAM. The graphics card, CPU and all other components are infinitely fast by comparison.

The game, graphics settings, and hardware on all three systems cause all three to run at 60fps. So here's the question: If you change the in-game graphics settings from "Low" to "High", which system's performance is most affected? How much are the other systems affected in comparison?

Lets say that this change in settings reduces the frame rate of the most affected system to 30fps. Which system will that be and what will the framerate of the other two systems be (somewhere between 30 and 60)?

As a second test, say you up the resolution to 1920x1080 but you leave the graphics settings on "Low". How are the systems affected in this situation?

 

[TenPc]

You have to specify all of your hardware, bottlenecking usually refers to different things that relate to the hardware. If your PSU is lacking the required 12v rail wattage then the GPU will have a shortfall and stop owrking when at its peak. If your ram is somewhat less than the game requires then your cpu is working extra time to provide speed and then has to draw more power that might be required by the video card thus causing a power shortfall somewhere.

If you hdd has less then 25% free space then virtual memory will suffer and the ram will be put under pressure to proviude memory.

Some games perform better on high resolutions, even older games but on the other hand, lower resolutions draw less power, less resources and less cpu usage.

60 frames per second is not slow, it's double the maximum that as it was as much as 5 years ago. If your video card is not up to performing the high FPS then you will burn out the video chips by forcing it to perform more than it is capable for any length of time.

Basically, specify all of your hardware including brand and model and version and wats etc and the games you are theoretically playing to get more replies.

 

[manofchalk]

The CPU bound rig will be the least affected by increasing graphical settings (including resolution), as the higher settings will mainly add a burden to the GPU. Though if you were to enable more physics settings, then the CPU rigs performance would degrade performance quite badly. RAM build would stay the same, GPU would be most affected.