Playing E2E:E, and a basemate has been doing Augmentation. Every time he makes some kind of block or machine from the mod (Impetus Diffuser, Stability Field Generator, Impetus Matrix) I can instantly tell, because looking in its general direction (even if it's behind many blocks or chunks) drops my frames from 45 average to 3 average. Any idea what could be causing this? I know E2E:E is a massive pack and it could be something else, but I'm certain that TA blocks are the one causing my frames to drop. Happens to a lot of other people on the server, but not everyone. I'd say around half the people, if not a little less, get the massive frame drop from TA stuff.

Yeah, massive packs don't make it easy to figure out. Since your server seems to be at endgame TA, there are quite a few different things that could be causing the issue:

• Flux Rifts - these are from base Thaumcraft but are required for Impetus. They use a shader for rendering, and will also make the garbage collector work very hard as it constantly allocates and throws away arrays every frame (press F3 and watch your memory usage while looking and not looking at a Flux Rift...).
• Starfield Glass - decorative block from TA that also uses shaders for rendering. Their rendering should be batched so that there is only 1 shader bind per shader type per frame, but it could still be an issue if there is tons of it around due to how it has to render individual visible cube faces currently.
• General TA machines with animations - these use the Forge animation system for their rendering. From what I can tell, at least on 1.12 barely anyone uses it sadly, so I wouldn't be surprised if something doesn't like it.

If you can profile the game to find out exactly where the issue is it would help a lot, but some other things that would help are:

1. Try disabling shaders in the TA config, under client options. This will make things look ugly, but will help rule out shaders.
2. As an experiment, see if you get similar frame drops in a singleplayer world after placing down Vis Regenerators. These blocks have animations but don't require flux rifts to work.
3. There should be an option in the TA client config to optimize Flux Rifts - I forget if I turned it on by default or not, but it will make Flux Rifts thrash memory slightly less. Fixing that renderer for real is on my todo list for Thaumcraft Fix but I don't know when I'm going to get to it.

Edit: whether the lagging people are using Optifine or similar mods would also be useful information.