I5 4210m 2.5Ghz burn test problem

I can't work this one out. The CPU should have a max speed of 3.2Ghz with turbo mode. But when I run the Intel burn test with CPU clock speed running in the background the clock speed is never going above 1.5Ghz. Even after running the standard test.

Any ideas why this might be?

I5 4210m 2.5Ghz burn test problem