If the client as you say uses more than 256mb of texture ram, you really need to look into how the asset loading/flushing works, running at max character textures with everything else set to medium will choke a 1gb gfx card on a 4gb computer while raiding after some time.
There's some noticeable chugging due to excessive swapping, and client shutdown can take as long as up to a minute if I have it running for some hours.
I know this isn't SM 3.0 related, but it's still a major issue concerning how good the game actually looks.
I agree. I remember hearing about this issue a few years back but at the time very few computers could have textures up very high so it wasn't as big of a concern I suppose. I have experienced this since I upgraded my computer and even just reloading the game doesn't fix the issue 100% because some of the eq2 data stays in ram/vram (or so I've been told/noticed poor performance); I have to restart my computer after every raid to get normal performance. Even shutting down windows takes an inordinate amount of time because it's clearing all the ram and flushing page file cache, etc.
I'm not well versed in our memory management, but we do have some team members who are taking a good hard look into it.