new loop and temp questions

[kewlboxer2]

Im finally back to try water cooling since early 2000's with fish pond pumps and car/ truck heater cores. Anyway I have the following being cooled in the loop

1090T @ 3.8/1.43v
R9 290X @ stock clocks

My setup is as follows
RX360 push
RX240 pull
XSPC Raystorm cpu block
AquaComputer block and backplate

Ambient currently is around 26-27c
Water temp @ idle 30.4c
CPU idle temp 36c
GPU idle temp 35c

After 10 minutes of prime95 small fft and furmark burn-in test

CPU @ 57c
GPU @ 47C
Water temp @ 38.1C and climbing

Why is my CPU temp so high?