Anisotropic Filtering tripling CPU usage, Dropping frame rate too

Hi.

I have a real problem: I was wondering why my computer’s frame rate was a bit low for a simple game…
Until I disabled anisotropic filtering, of which quadrupled my framerate. (200fps on, 2000fps off)

Any ideas? System specs:
Sandy Bridge Intel Core i3
Intel HD graphics 3000
4GB RAM

Aniso filtering should be entirely on the GPU. The HD 3000 is a pretty slow GPU and IIRC relies on system memory for textures. Anisotropic filtering requires many more texture taps, which requires a lot more memory bandwidth, which system RAM is not really designed for. That’s my best guess.

Huh, well, I could try lowering the anisotropy to something like 1 or 2, rather than having it on “forced on”

Point being though, one of my games doesn’t look too bad without it, so I might as well leave it as-is. Either way, thank you for this information.

And also, would such a problem affect mobile? :eyes:

Aniso filtering makes the most difference in when you have polygons that are large and lean away from the camera, like terrain or floors or walls of a building. For sure tuning the threshold or only enabling it on certain materials can get you a long ways.

It can be an issue on mobile, yes. The specifics differ, but mobile GPUs are usually dependent on system ram which is even slower than desktop system ram.