Random lock ups, freezes during a download and memory timing question

It depends on your graphics card.

While running this test.
Conservative: 80°C
Max: 90°C
Set your GPU fan speed to high for testing.

Daily heavy use, example gaming, 70°C.

Zeldafan1993 said:

ok so I ran it for 6 and a half - 7 mins and it hit 81 Celsius I don't know what I need to report really, but it didn't cause a crash it was using 99% of my GPU

You are suppose to look for artifacts.

From the tutorial I posted:

6. Watch for artifacts on the screen, and keep an eye on the temperature log. If you see artifacts, or the temperature levels out, stop the test.

For this test run minimum of 30 minutes.
Watch GPU temps, let us know what they level off at and if they continue to slowly climb.

artifacts - from the link in the tutorial.

Visual artifact
Visual artifacts are anomalies during visual representation of e.g. digital graphics and imagery.
[edit]
Examples in digital graphics

A screenshot of a Microsoft Windows XP application displaying a visual artifact. This was fixed in the next release, Windows Vista.
Image quality factors, different types of visual artifacts
Digital artifacts, visual artifacts resulting from digital image processing
Noise
Screen-door effect, also known as fixed-pattern noise (FPN), a visual artifact of digital projection technology
Distortion
Silk screen effect
Rainbow effect
Screen tearing
Purple fringing
Chromatic aberration
Moiré pattern