To all who cares 3D video games

thedrama

I have been playing video games since 2002, i mean about 10 years. In this time, i have learned so much related to video games aside from how they are programmed. However, there are still suspicions on my mind in certain cases. Especially the significance of VRAM and how lack of amount of this affects the gameplay and cause stuttering issues.


As far as i know, VRAM is much like the system memory(RAM) but this time used to speed up the calculations of graphical stuff for processing by GPU. Its quantity usually expressed with the size of textures used in the 3d video game and once the
space runs out there, CPU looks for space around, first on RAM and if there is no space on RAM as well, goes to hard drive.

According to these,


1) The first thing im curious about is when i clicked the game(specific name).exe, which things are immediately loaded into VRAM?

2) When inside the game(while playing), are the graphics data always loaded from the hard drive first or certain ones grabbed from VRAM?

3) While playing, which hardware causes the stuttering; CPU or graphics card?

Webmaster

1) That differs per game depending on choices the developers made. Some load all textures for a specific world/scene, others just the intro/menu/gui graphics. Differs per system too, e.g. on mobile devices as little as possible is loaded and textures are sometimes unloaded/released on purpose directly after use. Essentially every game has two primary functions, one to render the scene/frame, and one to update the scene (based on input, game logic and AI). During the update (also every frame or x times per second) it can also choose to load only what it needs to display in the next frame or "soon", e.g. when coming in range of the object in game.

2) If it's available in VRAM it will load it from there (cache) first. In particular for textures, texture coordinates and vertex coordinates (vertexes make up triangles/polygons which in turn make up the 3d model, textures are mapped to the vertexes using texture coordinates) all in the format the GPU handles directly. Instead of having to convert and read them from slow regular software arrays that in turn are filled by parsing a 3d asset (a model + its animations for example) from disk. The latter is relatively very slow and usually done at the start of level for larger models/characters/environments while smaller props are loaded on demand.

3) Depends on what in the software actually causes it but especially for modern games that make heavy use of OpenGL/DirectX optimizations the right graphics card can make all the difference (given that you have a decent CPU of course).

SteveLord

Stuttering/framerate loss can also be caused by an underpowered video card. Meaning, your powersupply cannot feed it enough juice to keep it stable.

A similar thing can happen when a poor CPU is combined with a flagship video card. Bottleneck created, framerate drops.