Turning on Power Save runs the CPU slower, lowering the score.
9000 specs - Exynos running at 1.9GHz
9005 specs - Snapdragon running at 2.3GHz
I have a 900A, also Snapdragon running at 2.3 GHz, and running the X-Note ROM I get 35944 on Antutu with Power Save off. I've gotten as low as the upper 28000s with other ROMs.
And it varies by individual phone. This is the second replacement I've gotten, so the 3rd phone. And It's not the fastest one I've had. (But at least it works - the other two stopped working.)