[SOLVED] PCIe 4.0 x8 vs PCIe 3.0 x16 same thing?

[mwstephenson85]

I have an x570 motherboard which has 4.0 PCIe x16 in the top slot.
It is stated that 4.0 x16 functions at 32GB/s
because it is double PCIe 3.0 that would mean 4.0 x8 functions at 16GB/s
Which mean its the same as 3.0 x16 which many people still use even for RTX 2080ti
infact there are people with PCIe 3.0 that SLI and go 8x 8x which is only 8GB/s for each RTX 2080ti

So with all this information we finally get to my question.

Is It this simple with PCIe 4.0 for example If I do some configuration which causes my top PCIe 4.0 x16 slot
to become x8 slot for my RTX2080ti is it going to matter?

I ask this because if it functions just fine in 3.0 x16 and thats the same thing as 4.0 x8 then its np right?

Is it not that simple?

For example if theoretically if A GPU was designed to fit a 4x slot like m.2 size but it was pcie 4.0 then its still getting 8GB/s and thats fast enough for most GPU's now a days, or does the socket actually being bigger matter more. I hope this makes sense. It may not make sense why I'm asking it, but I'm trying to see if the only thing that really matters is how much data can be pushed through the PCIe x(#) slot not that its physically a x2 x4 x8 x16 sized slot.

 

[kanewolf]

I have an x570 motherboard which has 4.0 PCIe x16 in the top slot.
It is stated that 4.0 x16 functions at 32GB/s
because it is double PCIe 3.0 that would mean 4.0 x8 functions at 16GB/s
Which mean its the same as 3.0 x16 which many people still use even for RTX 2080ti
infact there are people with PCIe 3.0 that SLI and go 8x 8x which is only 8GB/s for each RTX 2080ti

So with all this information we finally get to my question.

Is It this simple with PCIe 4.0 for example If I do some configuration which causes my top PCIe 4.0 x16 slot
to become x8 slot for my RTX2080ti is it going to matter?

I ask this because if it functions just fine in 3.0 x16 and thats the same thing as 4.0 x8 then its np right?

Is it not that simple?

For example if theoretically if A GPU was designed to fit a 4x slot like m.2 size but it was pcie 4.0 then its still getting 8GB/s and thats fast enough for most GPU's now a days, or does the socket actually being bigger matter more. I hope this makes sense. It may not make sense why I'm asking it, but I'm trying to see if the only thing that really matters is how much data can be pushed through the PCIe x(#) slot not that its physically a x2 x4 x8 x16 sized slot.

The transfer rate on a PCIe slot is dependent on the motherboard AND the device. So your RTX card is a 3.0 device. So the slot will run as a 3.0 x16 slot. OR if you put a second card in it will drop to a 3.0 x8 slot. ONLY if you had a 4.0 device would your math work.