Everyone,

 

I thought I knew this but I obviously didn't: is P3D more CPU or GPU based? I knew FSX didn't use squat out of the GPU, but I thought P3D was using it much more than the CPU.

 

My friend says that it's sort of a half and half, saying that "if you have a lower CPU and a higher GPU, you wouldn't get an increase in frames".

 

Anyone know the full answer to this?

 

 

I think it is very much a combination of CPU and GPU. Also your RAM speed. P3D has improved the spreading of the load off the CPU and across to the GPU but the CPU still works very hard in P3D. Previously there was a post somewhere here on Avsim that gave an indication on which sliders in P3D are more dependent on CPU, GPU or a mix of both.

 

Bottom line though, having the best CPU but an old GPU or vice verse will always cause a bottle neck in the system and result in less performance. The two work so closely together in handling data and processes that if one stalls or is slow, the other, no matter how fast, will be waiting around for the other to complete the current process.

The full answer can be summed up as follows: it depends (on the scenario).

 

P3D tends to be CPU bound (dense amounts of autogen, polygons, addon aircraft complexity, AI traffic, etc.) generally binds the CPU. But with regard to the GPU, it tends to lay back and let the CPU do the majority of the work unless there is either 1) a large amount of particulate matter in the environment (clouds and cloud layers, fog, effect smoke, etc.) and/or 2) the user has applied any SGSS anti-aliasing (e.g. the only AA that really has much of an effect in P3D).

 

And that's all I have to say about that.

Curious to know how much gpu terrain rendering actually adds to performance, does it help in every case or can it become deteriorating such as in bad weather?

 

Interestingly AS a320 is able to use gpu rendering for panels as opposed to cpu within p3d, not sure if other complex aircraft do this and how much that offloads from the cpu.

I knew FSX didn't use squat out of the GPU, but I thought P3D was using it much more than the CPU.

Depends on what your definition of using the GPU is. A better/newer GPU may not make much difference to performance in FSX but it will almost certainly improve the quality of the image by allowing you to use much higher resolutions and better anti-aliasing.

All,

 

Thank you for the information, I really appreciate it! I do have a few questions

 

 

 

Previously there was a post somewhere here on Avsim that gave an indication on which sliders in P3D are more dependent on CPU, GPU or a mix of both.
 

 

Do you happen to know where that post would  be? It would really help me out a lot!

 

 

 

3D tends to be CPU bound (dense amounts of autogen, polygons, addon aircraft complexity, AI traffic, etc.) generally binds the CPU. But with regard to the GPU, it tends to lay back and let the CPU do the majority of the work unless there is either 1) a large amount of particulate matter in the environment (clouds and cloud layers, fog, effect smoke, etc.) and/or 2) the user has applied any SGSS anti-aliasing (e.g. the only AA that really has much of an effect in P3D).

 

If I understand correctly, the amount of objects in P3D go towards the CPU, and the smoothness of those objects and envirement go towards the GPU?

 

 

 

Interestingly AS a320 is able to use gpu rendering for panels as opposed to cpu within p3d, not sure if other complex aircraft do this and how much that offloads from the cpu.

 

I always get terrible frames in the AS A320 even with using the GPU rendering, maybe a GPU upgrade would make a difference.

 

EDIT: In regards to the question about which sliders affect which part of the PC, I have found it in the AVSIM P3D Guide. Will be SUPER useful, thank you for telling me about that!

In my observation p3d being the same core will give you at most the same performance as fsx plus some additional graphics enhancements as shadows reflections etc that will additionally use up the gpu. I think it will be simpler to start off with fsx settings that worked well for you and then increase the p3d specific settings gradually. It is easier to reduce the latter without significant difference in visual quality so you may want to try that.

 

I had acceptable performance with the a320 although I do not have a top of the line gpu, so it might be the cpu bottlenecking. You might want to check in task manager if the main core is getting maxed out.

There is no one size fits all answer to this question, because everyone's system is different.