0_0 65 at idle? Wow that's kinda high. The 90 is quite high also although not that alarming. The 2 cards are too close apart, if you have a 3 way motherboard I would suggest to take the 2 more distant slots. You'll also want to buy yourself 1-2 more 140mm fans for the side panel to reduce those temperature. It's pretty obvious this has to do with an airflow problem, increase the airflow and you'll see the temperature drastically improve.
90C is high, but not too high for video cards. Current generation video cards are rated for 100C and above. I found this info somewhere before but I just can't remember where. Well, I'll say the temps are fine as long as your GPU heaters aren't affecting your ambient case temps and/or CPU temps to the point of surpassing their limits.
On another note, I think it should be mandatory to list max operating temps on the manufacturer's product page. I just spent 30 f*ckin minutes trying to google it and that sh*t pisses me off. I mean AMD does it for their CPU's, why not their GPU's?
Sorry, I've been pissed off about this for years lol.