I'm going to be running 56Gb , that should be more than enough for my requirements, I'm just waiting on my new 42RU rack which arrives tomorrow, transport outfit annihalated the first one.Just wondering who is ahead of the game, doesn't imply you have a switch for it, even just PCIE-4 nic to nic.
They should be, they're holding 8 lanes. I just can't understand how the QSFP-DD (Molex guys?) say that they are SFF-compatible,DD plugs are longer than QSFP28
p.10The QSFP-DD/QSFP6 DD800 cage and connector designs with 8 lanes are compatible with the 4 lanes QSFP28/QSFP112. The 7 QSFP-DD800 cage and connector is an incremental design with enhanced signal integrity and thermal which is 8 backwards compatible to 8 lanes QSFP-DD and 4 lanes QSFP28. The QSFP112 cage and connector is an 9 incremental design with enhanced signal integrity and thermal which is backwards compatible to 4 lanes 10 QSFP28/QSFP+
This means that while looking at the QSFP-DD connector, lanes 1-4 are the pads toward the back, and 5-8 are the pads towards the front. If a four-lane QSFP+/28/112 cable is inserted in a QSFP-DD slot, the front of the connector is missing, but the back is still in the right place to connect to lanes 1-4. On the other hand, a QSFP-DD cable inserted in a QSFP+/28/112 slot will bottom out and connect the front pads, which should be lanes 5-8, to the lane 1-4 pads in the connector. So, while a QSFP-DD/-DD800 port will accept a QSFP+/28/112 cable, properly connecting to the correct half of the lanes, a QSFP+/28/112 port will not be able to properly mate with a QSFP-DD cable.The QSFP-DD/QSFP-DD800 module edge connector consists of a single paddle card with 38 pads on the top
and 38 pads on the bottom of the paddle card for a total of 76 pads. The pads are defined in such a manner to
accommodate insertion of a classic QSFP+/QSFP28/QSFP112 module into a QSFP-DD/QSFP-DD800
receptacles. The classic QSFP+/QSFP28/QSFP112 signal locations are deeper on the paddlecard, so that
classic QSFP+/QSFP28/QSFP112 module pads only connect to the longer row of connector pads, leaving the
short row of connector pads unconnected in a QSFP+/QSFP28/QSFP112 applications.