ATI Radeon FPS drops

Question

Problem

For some reason my Radeon HD 5700 seems to suffer from FPS drops.

• 600W power supply should be enough
• The core temperature when the FPS dropped was ~53 C (127 F)

The GPU utilization is constant at 38% during the FPS drop (its not always 38%, sometimes its 65% or 24%, or any random between 0-100 but its always constant). Can you explain what happens here? Is there any workaround or fix?

More info: CPU is a Pentium 4 3.40 Ghz, the game used for testing is the free version of Trackmania at default settings, but it happens even on the lowest resolution and quality settings.

update:

Solution

Thanks to Mokubai, the culprit has been found. It was the CPU overheating.

Answer 1

Have you looked at the CPU and motherboard temperatures during these performance drops? It could be that either your CPU or motherboard chipset are overheating and throttling back and so reducing performance.

You can check most temperature sensors using Speedfan