From how you worded it, yes. You are probably socketing it into a physical x16 slot wired with only 1 lane of gen 4 PCIE. This is going to hamper your performance considerably. While you could technically run this configuration, I would very strongly recommend you use a different cooler if possible, so you can actually fit your GPU into the proper slot.
#GPU in pcie slot 4
steel pilot
worldly sluice
welp its going to have bandwidth of 4 lanes of gen 2