Sajin
Definitely getting up there. Are you running your fans at max? Mem can take up to 95c without any issues.

Sajin
When gaming I would definitely have the case fans on max.

AHowes
Room temps? I'd stop overclocking.. though the card will down clock the card to help keep those temps down anyway.

Setup some serious aggressive fan profiles for the cards 3 fans so they are not off on idle temps and start ramping up to 75/80% on load temps early. 50c have them cranking.. 65c or so 100%.

Its just tricky cause the mem/power temps will be much lower then the GPU early on but you would also want them the same as it ultimately helps the GPU temps as well.

And yes.. the case fans matter cause if they are not supplying the level of air your card is trying to pull, it will choke them and the card cant cool.

No one asked what case your using either. What is it?

Ever test with the case open to see if the temps are better?

Could always go old school and point a large house fan at the inside of the case to help cool it as well.

If the room temps are not high, then it could be a problem with the card heatsink.. maybe the thermal paste on the card isint great and not making proper contact.. but since everything is hot on the card and CPU its prob not that bad look at overall room temps or case cooling for the issue.

CraptacularOne
How are your fans and radiators configured in the P400? Could be an issue with feeding the GPU warmer air if you have the 360mm radiator configured as intake in the front of the case. Try removing the side panel and retesting and see what you get. If temps drop measurably you have a warm air intake issue and may be worth redoing the air flow in your case and try to configure the radiator to exhaust the warm air outside the case. What I think is happening is that your radiator is dumping warm air into your case, that's then being recycled into your GPU and then being heated up and dumped into your case again causing a cascade of warm air. 
 
While your memory is technically fine to run at 90C as it's rated up to 95C for the life of the card, I'd still try rearranging your fans to see if you could drop it a bit. 

DeadlyMercury
Well, as for temperatures - there is nothing bad if gpu going up to 80C and mem up to 90C.
But it is not normal in terms of max fan rpm. That should not be like that. It could be normal if fans running silently (like mine asus rog strix going up to 86C with fans up to 40%), but if you are running fans at maximum - temps should be like in 65-70C range, so something is wrong.
 
And one thing that could be wrong - is rad mounted at front as intake: actually it is not warming air up significantly, but it is strongly obstructs airflow, so your problem could be bad intake and if you can't mount your rad on top as exhaust - you can try to add fans on it to make a push-pull configuration, which increase airflow through radiator so your gpu will get more air. 
Or you can try to make more intake in your case if you have some bottom option fans.

CraptacularOne
I have the same case and mounted my radiators on the top and rear as exhaust. You can check the pics in my mods rigs page for reference. 

DeadlyMercury
So, you are getting 78C with opened sidepanel? On max rpm?
If so, that is not normal and can't be explained with low airflow. So it could be bad TIM application. That leads to either RMA or checking and reapplying TIM.

DeadlyMercury

papaniz
 
Sorry for the confusion, all panels are closed now

And how hot is it with opened panel?

DeadlyMercury
66C is fine for ftw3 on max power limit.
So nothing wrong with your gpu.
 
Yeah, that means that air in case is warm. But it is warmed up with gpu, not your cpu aio ;)
So the problem is in low intake, obstructed with rad. 
 
Did you mounted same LL120 on your rad as it was already installed? This fans have good static pressure so they are good for radiator, but maybe you mounted something with low pressure as push, so results are not great.
 

CraptacularOne

papaniz

DeadlyMercury

papaniz
 
Sorry for the confusion, all panels are closed now

And how hot is it with opened panel?

Wow okay, so I think when I was originally testing the temps with the opened panels I must've had the wrong profile set and didn't notice. I overlooked something.
 
Now I made sure I'm running the same test as the OP, with the side glass panel and front panel off the card on load is running at 66C with MEM2 at 72C and MEM3 at 74C. When I took off the front panel only it went down about 4C to about 74C and when I took off the glass panel and front panel it went down to 66C. This is all on maximum load running Heaven and maximum RPMs for case and gpu fans. That is a huge difference. So does this suggest the air in my case is too warm? 
 
Thanks for the help in finding this issue everyone! 

OK you have the older P400 not the newer model with the mesh front like I do. Yeah that's exactly what I thought was happening you are dumping warm air from the front mounted radiator into your case and with what little cool air your case can draw in you are just creating a runaway heating loop. You can definitely fit the 360mm rad in the top on mine. I'm sure the tooling is still the same between our cases so it should work with yours too. I have plenty of room on mine to fit a 360mm just didn't since I already had a 240mm and a 120mm from previous builds.