Inspiron 5675, motherboard PCIe x16 slots running at x8 speed?

There is not a "real time" FPS (frames per second) performance hit going from PCIe x16 to x8. Dell accepted and verified this conclusion when building the Inspiron 5675 Desktop.

For Inspiron 5675 Desktop that shipped with an AMD Ryzen Summit Ridge CPU, the PCIe slots technical specifications are as follows;
Slot 1 = PCIe x16, full length running at PCIe x8 Gen3 speed
Slot 2 = PCIe x1, Gen3 speed
Slot 3 = PCIe x1, Gen2 speed
Slot 4 = PCIe x16, full length running at PCIe x8 Gen3 speed

For Inspiron 5675 Desktop that shipped with an AMD Bristol Ridge CPU, the PCIe slots technical specifications are as follows;
Slot 1 = PCIe x16, full length running at PCIe x8 Gen3 speed
Slot 2 = PCIe x1, Gen3 speed
Slot 3 = PCIe x1, Gen2 speed
Slot 4 = PCIe x1, Gen2 speed

I was told by tech support that the motherboard has 2 PCIe x16 slots and that they run at x8 speed.   I found this out when i was inquiring as to which slots are running at Gen 2.0 and Gen 3.0 speeds.

PCI-E Gen2  x16 and PCI-E Gen3  x8 are one and the same speed.

No difference whatsoever in bandwidth.

Speed

8-Lane (×8) and 16-lane (×16) links, in each direction:

PCI-E v. 1.x (2.5 GT/s):
2   GB/s (×8)
4   GB/s (×16)

PCI-E v. 2.x (5 GT/s):
4   GB/s (×8)
8   GB/s (×16)

PCI-E v. 3.x (8 GT/s):
8   GB/s (×8)
16 GB/s (×16)

Real world.....you would never notice the difference.  I've been building machines a lot of years, a motherboard with two pcie x16 slots that run full speed with two cards is a very expensive board.  My last gigabyte had this capability and was three hundred dollars (3+ years ago) new, you won't find a three hundred dollar motherboard in a thousand dollar machine I can nearly guarantee you. 

If you look at the fine print just about any sli or crossfire board says in the fine print that when more than one card is installed the pcie x16 run at a slower speed.  You aren't going to get filet mignon for sirloin prices guy sorry to say. 

Then, now that we're past the buss speed question what video card are you plugging in there?  If you're not buying top of the line cards it's not going to be exceeding the capabilities of 8x in the first place.  If you think you can get a better deal someplace else go for it, only way is a custom built system that you will pay quite a bit more for.  My 5675 is a stand in until the threadripper isn't so insanely expensive and will be a spare machine when I rebuild my big rig.