What is the difference between an RTX 2080 max q and full size RTX 2080 in a laptop.

[Ragavron]

I have brought a laptop HP omen 17 inches with FULL SIZE RTX 2080 instead of max q design. so does it really give a desktop like performance in a laptop or just a gimmick by the company?

[Analog]

1 minute ago, Ragavron said:

I have brought a laptop HP omen 17 inches with FULL SIZE RTX 2080 instead of max q design. so does it really give a desktop like performance in a laptop or just a gimmick by the company?

Max-Q branded cards are lower TDP units. Otherwise said, you don't get the full performance. 

[Bobbysixjp]

5 hours ago, Ragavron said:

I have brought a laptop HP omen 17 inches with FULL SIZE RTX 2080 instead of max q design. so does it really give a desktop like performance in a laptop or just a gimmick by the company?

A maxq 2080 is not as powerful as the desktop equivalent because of lower TDP and limited cooling potential. It’s probably equivalent to a desktop RTX 2060. 
Just noticed you have a desktop 2080 in a laptop? This will probably give you better performance than a maxq 2080 but you may still be limited by TDP and thermal throttling. Why don’t you run some benchmarks and compare with the many available benchmarks for the desktop 2080?