3dMark now includes a Stress Test

[Bacon1]

http://www.futuremark.com/pressreleases/check-your-pcs-stability-with-new-3dmark-stress-tests

 

[Raising]

10 years since a new 3Dmark.. proper DX12 benchmark still missing

 

[Elixer]

Each 3DMark Stress Test runs in a loop without pausing for loading screens or other breaks. In 3DMark Advanced Edition, the test loops 20 times and runs for around 10 minutes, which is usually enough to uncover any stability or cooling issues. With 3DMark Professional Edition, you can set any number of loops from 2 to 5,000.

Or use Furmark for free for however long you want.