I am a bit of a modder myself, though I haven't released much for Oblivion, and I know a thing or two about 3D graphics performance. The huge amount of draw calls you discovered seemed unlikely to me, so I went and checked for myself. I used ReShade to measure draw calls, and to my surprise I could confirm your findings for Cheydinhal. In other places, draw calls were much, much lower, with similar amounts of Objects (and sub-meshes), like the IC Market district. Also, while disabling the houses caused draw calls to go down by about 5000 per house, other objects had very little effect, like the cathedral, even though it is a more complex model.
I discovered that this ONLY happens with the Unofficial Patch versions of these models and not with the original ones, and optimizing the UOP ones with Pyffi fixed the problem.
Hello,
I'm sorry for abusing your bug reporting section, but I could find no other way to contact you.
I read your blog post about bad performance in Cheydinhal: https://katawful.github.io/oblivion/cheydinhalproblem
I am a bit of a modder myself, though I haven't released much for Oblivion, and I know a thing or two about 3D graphics performance. The huge amount of draw calls you discovered seemed unlikely to me, so I went and checked for myself. I used ReShade to measure draw calls, and to my surprise I could confirm your findings for Cheydinhal. In other places, draw calls were much, much lower, with similar amounts of Objects (and sub-meshes), like the IC Market district. Also, while disabling the houses caused draw calls to go down by about 5000 per house, other objects had very little effect, like the cathedral, even though it is a more complex model.
I discovered that this ONLY happens with the Unofficial Patch versions of these models and not with the original ones, and optimizing the UOP ones with Pyffi fixed the problem.
I have described the issue and its cause in detail in a comment on the nexus page of the Unofficial Patch, it is currently at the top (I posted as "Pherim"): https://www.nexusmods.com/oblivion/mods/5296?tab=posts
Here is the direct link to the forum version of the post: https://forums.nexusmods.com/index.php?/topic/22693-unofficial-oblivion-patch/page-276#entry98752533
If you have any further questions about this, feel free to ask.