Did you try a clean driver install?
That's far too high for idling!... one little note, its idling temp seems to be 86-87c which seems very high to me.
Get msi afterburner (or some other program similar) and set a custom fan curve. Try it with the fans on 100% to start with to see if that stops the throttling. If it doesn't then it might be something wrong with the card or your case and other air flow/heat problems.
Been fiddling with this all day, have reinstalled the software twice, have reseated the card twice, have tried a heap of gpu temp software and gpu stress software.
It a nutshell it comes down to the same thing. idling the card hits the mid to upper 80's. (84-88c) when stressed it quickly ramps up to over 90c and at that point the performance takes a massive nose dive.
I cannot play Elite for more than literally a minute and half before the temp gets too high and the card throttles back.
I'm going to put my old GTX 650 back in now, at least I can play a game that way. the 770 is useless. I'm not sure if I can get a refund as I've fitted it and used it but I won't simply lose £230 for nothing![]()
Just out of interest, have you tried running with your case left open?
I'd try and rma the card but don't mention you used msi afterburner or other program for altering the fan curve as they could use that to invalidate the warranty and accuse you of overclocking. If you can run a 650 fine then it definitely sounds like the card is at fault. My 680 was idling around 60 in a closed fractal node 605 case. My 970 idles at 50 and the fans don't even turn on till it hits 60.
I phoned the shop I bought it at and they said to post it back or take it in and luckily its only 2-3 miles away from me and a friend gave me a lift. (I don't drive)
They took the card back which is good as I was worried that once I'd opened the box and fitted it they wouldn't replace it. anyway there was no other Gigabyte 770's in the shop only a brand I've not really heard of.
EVGA 770 SC. The price was £15 more but he very kindly waived that and let me do a straight swap. I've not fitted the new card yet but this has only 2 fans, the other had 3. maybe signs that its not as good?
anyway I'll let you know how it does when I fit it.