Go to 'My Documents', open the BioWare folder, then the Mass Effect folder, then the folder named Config.
Inside, you'll find a document entitled 'Bioengine.ini'.
Open that up, and search the document for the subtitle 'TextureLODsettings'.
[TextureLODSettings]
//TEXTUREGROUP_Character=(MinLODSize=1024,MaxLODSize=4096,LODBias=0)
//TEXTUREGROUP_CharacterNormalMap=(MinLODSize=1024,MaxLODSize=4096,LODBias=0)
//TEXTUREGROUP_Effects=(MinLODSize=1024,MaxLODSize=4096,LODBias=0)
TEXTUREGROUP_LightAndShadowMap=(MinLODSize=1024,MaxLODSize=4096,LODBias=0)
TEXTUREGROUP_RenderTarget=(MinLODSize=8,MaxLODSize=4096,LODBias=0)
//TEXTUREGROUP_Skybox=(MinLODSize=1024,MaxLODSize=4096,LODBias=0)
//TEXTUREGROUP_UI=(MinLODSize=1024,MaxLODSize=4096,LODBias=0)
//TEXTUREGROUP_Vehicle=(MinLODSize=1024,MaxLODSize=4096,LODBias=0)
//TEXTUREGROUP_VehicleNormalMap=(MinLODSize=1024,MaxLODSize=4096,LODBias=0)
//TEXTUREGROUP_Weapon=(MinLODSize=1024,MaxLODSize=4096,LODBias=0)
//TEXTUREGROUP_WeaponNormalMap=(MinLODSize=1024,MaxLODSize=4096,LODBias=0)
Copy and paste this on top of what is already there, and then save.
If it looks the same, then you've already got it running on optimal texture settings.