I am new to infiniband networks, but i need to extend an existing infiniband cluster with some nodes. During my exploratory web-research I came across some to me ambiguous descriptions of cables, connectors and switches.
According to Wikipedia QSFP is specified as 4x1Gb/s, and QSFP+ as 4×10 or 40 Gb/s. However many suppliers on the web are offering QSFP cables and switches for 40 Gb/s. This some how does not seem to match with the overviews on different infiniband cabling that i found.
Is this just sloppy naming and are these QSFP 40Gb/s actually QSFP+?
Is there a difference in the physical connections between QSFP and QSFP+? Or are just the cables of a different quality (like CAT6 and CAT7 cables), but is the shape of the connectors the same?
I would be very thankful if some body could clarify this a bit.
Best Answer
QSFP+ stands for Quad (4-channel) Small Form-Factor Pluggable Plus, also known as QSFP10. Now QSFP/QSFP+/QSFP28 all use 4 channels to pass data.
QSFP - People mistake this for QSFP+ ALL the time. Make sure you read the full description. QSFP is a 4x4Gbps (16GB) transceiver/cable. These are outdated and not really used from what I have seen
QSFP+ these are 40G or 4x10Gbps as each channel has 10GB speeds. These can be a single cable, QSFP+ to QSFP+ or QSFP+ breakout to 4xSFP+
QSFP28 are 100G cables, can also be 4x25G or 2x50G breakout cables.