SFP28 ports are backward compatible with SFP+sfp+
Ya, but those aren't PCIe gen 4.ConnectX-4 are also SFP28
No they are x8. The E810-XXVDA2 is dual port. However technically it is possible to run them on a 4x Slot, if you have an open ended one, or there are mainboard which have a physical x8 slot, with x4 connection.
NICs also tend to increase lane count requirements instead of jumping up a PCIe generation. Going from x4 to x8 isn't a big deal in the server market, but moving to the next gen PCIe means that you lose a lot of potential customers.NICs in general tend to lag behind in terms of Gen / slots.
or they just keep using he older model.... not a huge deal but, providing the option and expanding their customer base would make for more sales.lose a lot of potential customers.
This is going to be a problem for a while with PCIe 5.0 motherboards. Because PCIe negotiates to the slowest of the speeds between the card and the host, you have PCIe 5.0 slots with the same number of lanes as 4.0 or 3.0 version of the motherboard, so that the devices that exist now will be able to run at full lanes.The reason for my question is that I'm trying to pack as many ports that I can on my motherboard which only has 1 free PCIe5 slot which is only x4.
Yeah thanks to Broadcom, PCIe PLX switches are now so expensive that it doesn't make senseMany of us building servers would rather have PCIe 5.0 only for a couple of slots and the M.2 devices, and have a lot of slots with PCIe 4.0 (or even 3.0). Until I can get a PCIe 5.0 x8 card with support for eight NVMe drives at PCIe 3.0 speeds (if all drives are active), I'd rather have four PCI 3.0 x8 (or two x16) slots.