xrayys sse frame drops ctd knowledge base

+++ please refer to my user profile about me page and follow my recommendations how to use my mods as an addition to nexusmods terms +++

this mod is intended to make you aware of the background of performance drops and to be a stutter workaround knowledge base for people who encounter fps drops in dense areas with (too) many objects and clutter.  you are wondering why this happens even with capable gaming hardware ?

please take 3 minutes to read the whole page. if you have the time also study many useful posts in the mod thread!

background: skyrim se has the same limitation as fo4 but it includes no special draw call optimization method like fo4. (see also my fo4 knowledge base).

draw calls are limited in dx11 games to about max. 12000 draw calls depending on your hardware including drivers and the efficiency of the game engine.

the problem is that the connection to deliver draw calls from cpu to gpu works only single threaded in dx11 (with a minimal exception regarding nvidia drivers). no cpu on this planet even with highest ipc on one core and 128 cores has enough power to deliver an amount of much more than 12000-15000 draw calls to the gpu without getting into trouble (which means stutter, in worst case ctd if the number raises beyond that limit for a significant amount of time).

dx12 or vulkan interface should solve this problem by allowing multi threaded draw call operations but it is not available for skyrim and fo4 and does not always work as perfect as assumed.

many settings influence the draw call number: the fov setting, the resolution you play, the amount of displayed objects and also many hidden objects depending on the optimization like culling. so an exterior scenery often puts much more strain on your hardware than a limited object amount of an interior scenery.

so be aware of the practical draw call limit depending on the game you play and you would like to mod:

for dx9 it is about 6000-10000 (oblivion and oldrim), depending on the game engine and hw (uses only one cpu  thread!).

all this is true for oblivion. skyrim le and se (64bit) and also fo3, fnv and fo4 (64bit) based one the same game engine.

fo4 includes an extra performance optimization method to be aware of!

for dx11 it is about 11000 to 12000 draw calls (fo4 and skyrim se) depending on the game engine and hw (uses only one cpu  thread!). you can see how the fps drop above this value due to cpu and engine bottleneck, regardless how strong your gpu is. in regions of 15000 draw calls you already lost 20% of your fps or even more.

and dx12/vulkan is able to handle 200000 and even much more draw calls if consequently optimized (it uses better cpu draw call handling).