SSE Enb is worse on performance than the old one.
i disagree on this part im using rudy enb for both games with almost same visual mods SMIM + Noble skyrim HD + verdant grass + SFO and im getting smooth framerates on SSE than i had on oldrim. also games feels more smooth on SSE whereas on oldrim i get many stutters.
I'm not an expert on these matters, but from my understanding, I think they could both be true.
Performance in a software is determined by where bottlenecks are it's entirely possible different type of bottlenecks happen with different settings.
For instance, SSE is much better memory wise and there's little doubt about it. And if you had stutters before, it usually suggests memory related issues. So, it's entirely possible - as I myself experienced when I briefly tried SSE - that SSE's much better on performance in such a scenario.
But also, it's possible that it could be worse in raw rendering speed, like from such a reason mentioned above.
I tend to agree with you on this one though, because I had, in general, much more troubles with memory than low fps with Oldrim. And I still cannot even utilize the whole video ram due to limitation with DX9 on Windows 10, which wouldn't happen on SSE.
I don't know how much overhead duplicating buffers might incur, but my uneducated guess is that it couldn't be much worse than such problems like only using half of VRam I actually have.
Anyway, I think I can now confirm my suspicion thanks to such informative posts like Shiratamas.
It seems I might have to wait much longer than I thought I should before I migrate to SSE, as lacking SSS support alone is sufficient for me to stick with Oldrim.
(I believe it could be quite an understandable position, because... well... it's LL so we all love to see much skins, don't we? )