Where you are applying for the Global Talent visa outside the UK, you should usually get a decision within 3 weeks.
Where you are applying for the Global Talent visa within the UK, the Home Office aim to provide you with a decision within 8 weeks.
If you require a quicker decision on your application you can pay for a premium service. The Super Priority Service provides a decision by the end of the next working day after you attended the visa application centre. This costs an extra £800.