I've waited a liitle to cool down the gpu, and then blasted it with best settings from benchmarks

Just that, the gpu was cool in the beginning of the run, has made difference (7990 was with hot gpu, and 8002 was with cold gpu at start

, and vram was overclocked to 2830, and pl was 110 in both cases).
Hot gpu had 2805 MHz max in vram, but cold gpu had 2815 MHz max in vram.
run 8 vs run 25, look at the gpuz

(the runs are numbered, and pictures are correlated

)
Edit, -90 is unstable even in steel nomad ^^