Question GTX 1080 Possible Heat Problem

[Marath]

I have a ATX Cooler Master
I5-6400 4 2,70 Ghz
overclock 3,3 Ghz
Motherboard-asus EX B150M-V3 intel lga 1151 ddr4
8gb ram ddr4 2133Mhz hyperx
graphics 1050 Ti 4gb
Disc ssd 480gb
I'm considering to buy a second hand used gtx 1080. I believe that the PCI Express 3.0/2.0 x16 is not good enough for It. It should be pci express 5.0 correct?
However I'm prepared to that loss of performance because one day I could use, in future, this 1080 in a upgraded setup. The problem is: will it over heat my current setup? Thanks to you all.

 

[rgd1101]

pcie 4.0 not even out yet

about overheating, it about your case/fan

 

[Marath]

Thanks. You are correct. A seller tells me that about pcie5.0 an in fact it does not even exists .