build 1045/6 was TERRIBLE. The lag / fps drop is better with build 1056 but it's not back to pre-1045 FPS. I dunno what they did but it's a mess... :( [edit] -- so the FPS nightmare began when they fixed "lag shot." by making the whole game lag. Then in bld1045 they changed the way buildings/blocks check for leaks in the code (I assume) and more lag from a totally diff. bug. I love that they wanna fix it but problems have compounded. also, one part of the many FPS bugs around is FOV: in options, what is your FOV? And if high number, switch to 3rd person means more rendering processor time needed. Not a solution, just identification of the problem... Thus far no solution ...
I built a new rig and tried out the latest build... no FPS drops at all on the same vessel. It's probably optimizations in the game that improved performance.