Upgrade laptop?

My laptop has a 7700HQ and a gtx 1070. I have a free mini pci slot so I could upgrade the GPU, does that make sense and with which gpu?

You can't upgrade your notebook to 99.9654%.

You could connect a GPU dock to the Mini PCIe, but that's not really tingling. And also expensive. Then a case is needed, electricity has to go out, …

So sry was poorly worded. I can connect an external graphics card housing + graphics card. The question is, does it make sense

Probably not. If only then an RTX 2080 (ti). Everything below doesn't really have the insane performance gain. Nuja. Are from 750 euro (1,100 euro) around for the GPU alone. Plus a case. It starts somewhere around 250 euro. And probably a bit of freaking work too, until you can reasonably connect all of this to the Mini PCIe.

Ok, thanks, why would e.g. An Rtx 2070 or 2060 super nothing?

That would be fine. But the increase in performance is not that great now.

With the effort and costs, I would like to expect a doubling or the like.

The RTX 2060S / 2070 probably has 25% more power somewhere. The 2070 Super then 40-45%. Only with the RTX 2080 Ti are you roughly doubled.