@Hodgman I tried to find two positions where they have about the same frame rate and frame time:
The so called "slow" facing:
The "fast" facing:
The frame times are very interesting i think. The "pre frame time" is a bit a misleading title, its the actual time from glClear until SwapBuffers. The "Post Frame Time" is the time from the beginning of SwapBuffers to the end of SwapBuffers. SwapBuffers is also calling that NtGdiDdDDIEscape which gets most of the samples in the profiler. This is also where the difference happens when im using roughly the same part of the landscape for both facings. The slower uses 2.6ms in SwapBuffers, the faster one uses 1.6ms in SwapBuffers. The "pre Frame Time" (the drawing itself) is proportional to the number of indices/draw calls.
I assume the above is because the draw commands are actually executed when SwapBuffers flushes the queue? But what is this NtGdiDdDDIEscape function thats using up most of the time in SwapBuffers according to the profiler?