GPU overheating, tried everything recommended

[Daemien]

As the title says my GPU (AMD Radeon R7 240) is overheating. I have 2 computers (Mine and my friends). The GPU is overheating in my computer, but not in his. When it overheats, the screen goes black, computer is still running, but there is nothing i can do except shut it down manually.
Compiter 1 (My computer) specs:

• 
  AMD Phenom II X4 925 Processor (2.80 GHz)
  AMD Radeon R7 240 low profile
  2x 4GB DDR3 memory
  Codegen 500w atx 2.03 P4 400x

Computer 2 specs:

• 
  Intel core i5 X4 650 (3.20 GHz)
  AMD Radeon HD 5670
  2x 2GB DDR3 memory
  MS PRO 550W ATX P4 power supply

Things that i have tried, in order:

• 
  -Cleaning the dust from both computers
  -Checking for the newest drivers
  -Applying new thermal paste
  -Side panels on both computers are removed so the air flow shouldn't be a problem
  -I put my graphics card (R7 240) in computer 2 - everything is fine, played a couple of games, the GPU gets a little hot, but there were no problems. Stress tested it with FurMark. Temperatre pictures (links) in the spoiler
  
  Spoiler

  Computer 2 with AMD Radeon R7 240
  GPU 1 Tepmerature
  GPU 1 Stress test
  -Put his graphics card (Radeon HD 5670) in computer 1- everything is fine, played a game for an hour, stress test nothing strange. Temperature pics in the spoiler
  
  Spoiler

  Computer 1 with AMD Radeon HD 5670
  GPU 2 temperatures
  GPU 2 stress tes
  -Computer 2 works fine so there is no need to Check temperatures
  -Computer 1 with AMD Radeon R7 240 overheats in about 5 minutes of playing World of Warcraft on fairly low settings. The temperatures reach about 98°C and it shuts down. There are no pictures, but i can get them if necessary

Also it should be noted that Computer 2 doesn't have a hard disk, so both computers have the same (Swapped it each time i changed the computer and reinstalled the appropriate drivers)

 

[kevin freels]

So first of all, removing the side panel isn't going to help. More likely it will hurt. What you want is cool air being pulled in one way, pulled across the mobo, and exiting the machine warmer. You can only do this with a sealed machine with limited entrance and exit areas for air and fans to move it. Otherwise, the thing just becomes a heat trap and the fans just pull the nearest cooler denser air right from the sides of the fan from outside the case while air over the mobo hangs and gets hotter.

I would take a good hard look at the fans. Possibly a replacement fan was installed the wrong direction, or the fans themselves are just inadequate. I would also check to make sure the proper place for the air to enter and exit have plenty of clearance. If either is close to a wall or side of a desk you'll have trouble.

It could be that the case itself is inadequate for what you want to do. In that case, you could try some liquid cooling, case modification and adding more fans, or getting a new case. If adding fans the designer already made a decision of positive or negative pressure based on the layout so be sure to add fans and new openings in equal pairs near the original fans if possible. So for example, a pair of 3 inch fans with one pointing in close to where the existing fan points in and another facing out near where the other facing out is. (Usually the front is in and the back is out but not always) Other options might be to put one in the top of the case to evacuate heat more rapidly but you have to be careful not to drop stuff in it and also make sure you place it near the back if the back is the current exit (and usually the PSU is there) or to the front if the exit is in the front.

You'll need to think it through carefully. You're after balanced pressure and maximum airflow.

If it were me, I'd be looking for a new case with more fan space and airflow. Cases are inexpensive enough and I get bored with mine easily. lol