We are very sorry to hear that a fairly large number of people are experiencing bad performance when running X Rebirth. I have looked through more than 150 DXDiags already and I would like to post a few conclusions. First of all the most important thing: Some of these definitely show bugs in our engine when running on specific hardware and we are working on fixing this as fast as possible.
This being said however there are also a lot of misunderstandings on what framerate is achievable with which system and graphics settings combination. *UPDATE* - Available memory can affect performance
Looking through DXDiags in the last few days we have seen a number of oddly balanced machines. Machines with very powerful GPUs (680 / 780 etc), but with only 6GB of ram for example. While this is above our minimum system requirements, it is a combination that does not work well. Unfortunately X Rebirth behaves very different from a first person shooter in terms of performance. Since we have a lot of background AI and pathing tasks crunching heavily on memory intensive operations, sometimes this can conflict with the memory intensive graphics calculations. If the performance of the game suddenly drops it may be because your machine is swapping memory. This is only one of many possible causes obviously. We ARE working on other performance improvements, but it is important to understand that with any "above midrange" system you are far more likely to be memory or CPU bound than that you are GPU bound (this also means in these cases graphics settings have no effect).What is causing the low framerate: CPU or GPU
One thing that you will find is different with X Rebirth compared to most mainstream graphic intensive games (read shooters) nowadays, is that X Rebirth has very high requirements for your CPU. Almost all mass market mainstream titles nowadays are render bound (by the GPU). With X Rebirth this is only true in about half the situations.
Changing your graphic settings can have an effect on both the CPU as well as the GPU. If you have a very fast graphic card (see section below for top range models), then some of the graphic settings (shader quality and resolution) are not very relevant for you, because your system will always only be as fast as the CPU allows it to be.
Settings like the LOD level, the view distance and enabling the shadows on the other hand also greatly affect the CPU load. Do not get fooled by the fact that turning LOD and view distances to low may not have an effect immediately when you try it out. The LOD and viewdistance are greatly dependent on the situation in the game. It may have zero effect on the framerate in a normal zone but great effect in an asteroid field.The game uses my integrated intel graphic card and not my nvidia card.
If you have an nvidia card, to force the nvidia card :
- nvidia configuration pannel
- 3D parameters
- software param
- add xrebirth.exe
- force nvidia processorMid range graphic cards (this includes high end models with an "M" for mobility at the end.):
I am seeing a lot of people with such mid range graphic cards running the game in very high resolutions and high graphic settings. On these systems it is strongly suggested to reduce those settings that affect the fillrate. Either run the game with NO AA, and shaders set to LOW or set the resolution to 720p. In addition we suggest to turn of shadows for the time being on such systems. High end machines (e.g: Hexacore CPUs with NVidia 680 or above)
We see quite a few people with systems that we can only described as "high end". Some of these systems are not experiencing the framerates they would like to see. This however falls into two groups: Those who really see a bug in our game where the FPS is throttled for strange reasons that are being investigated and those that have stable framerate and expect more.
If your game is fast most of the time but only slow in nebulas try if turning off AA (Antialiasing) changes the performance significantly. If yes then you are render bound in nebulas. Please report to firstname.lastname@example.org
with your specs and we will investigate.
SLI - Unfortunately we have not yet optimized the game at all for SLI systems and based on reports we hear SLI actually hurts rather then helps performance. We will investigate this ASAP but for now we suggest that you disable SLI rendering.
We will improve the performance across all systems. On high end systems like the ones described in this chapter, there is definitely most room for improvement. However X Rebirth will always remain a very CPU heavy game which can not achieve the same framerate that you may be used to from very graphic intensive first person shooters. Technical details for the experts:
As I have explained above our engine is oftentimes CPU bound because of the massive AI simulation going on in the background. This is happening on multiple threads, but there are always two threads which mostly limit the framerate. This means the game will greatly benefit from a quadcore machine where two cores can crunch on our two main threads, one core can do the graphic driver code and the fourth one is free for the lower priority threads of our game such as pathing calculations, loading and sound. More cores will unfortunately not help much at this point in time.