When i started my pc, the fan will be very noisy and always running on 99%.
CPU temperature during gaming is 70 degree celcius++, non gaming is 40 degree celcius++
Graphic card is radeon 6950

Usually i can play for like 4-5 hours and no problem. After that, my dota2 item ingame item will look weird. For example i have a skull basher on my slot, but i see it as a black box only and nothing shown. Haldway through the game it will be like this and i cant move it around my slot inventory. Some item (non upgradeable) like a ring and scroll of town portal, the item image in my inventory slot still looks ok.

What is the problem?