I recomend turning VBOs on in the video settings when using a 3D texture pack, it seemed to remove a ton of the lag, for example when in a plains biome with all the grass.

This is my SimpleJCraft texture pack with custom 3D block models. 

The texture pack is 16x16 and is for minecraft 1.8.



If you are new to resource or texture packs, the way to use them in minecraft is-
1. Download the resource pack
2. In minecraft, click 'Options...', then click 'Resource packs...', then click 'Open resource pack folder'
3. Go to to folder where you downloaded the resource pack and copy and paste the zipped folder to the minecraft resource pack folder
4. Then in the minecraft client, choose the texture pack, click done, and have fun playing minecraft