I'm trying to figure out how the PCH PCI-E lanes are allocated on the GA-Z97X-UD3H-BK. Specifically, whether the 4x slot gets disabled altogether when the 1x slots are populated, or it just gets downgraded to 1x.

This page is pretty ambiguous:

But then this map shows 3 1x *or* 1 4x, which would suggest that the 4x slot is completely disabled if the 1x slots are used:

However, there is a setting in the BIOS to select between 1x and 4x operation for the 4x slot, and this setting would be redundant if the 4x slot could not be used simultaneously with the other 1x slots, as that is the only time you would need to set it to 1x:

Not to mention that there are 4 PCI-E lanes available, so why would the fourth one be wasted by restricting you to only 3 1x connections if you weren't using a 4x card in the 4x slot. It seems to me that the configs would be 4 1x or 1 4x, and the map in the manual should actually look like this:

Is that correct?