[Nom1fan]

Let's calculate together:

Resolution: 3840x2160
Bit-Depth: 10 stored in 16 bit aligned data types
Format: NV12 with 10 bit precission YUV420
Assumption: Maximum Number of reference frames: 16
Two additional renderbuffers: 2 (not needed by decoder btw.)

(3840*2160*2*1.5*18) / (1024 * 1024) ~ 432 MB ...

Edit: And this was for Level 6.1 - for 5.1 (just 6 reference frames), it would be 1/3 e.g. 144 MB

 So any idea what's wrong with my setup? If it isn't hardware, then what's wrong with the software?