Connectors Keep Pace
for 100G Ethernet
Molex
Joe Dambach – New Product Development Manager
Jay Neer – Industry Standards Manager
The Data Center Interconnection Landscape
Racks - and Rows of Racks
Today’s 10G “Top” of Rack Switch
(which can be located wherever appropriate)
10GbE
48 ports of SFP+
144 ports with QSFP+
Today’s Data Center Interconnects
Switch
(4-12 in.)
QSFP+
Retimers
10m-10km
SFP+
Server
(2-4 in.)
MAC
(2-4 in.)
MAC
(2-4 in.)
MAC
(2-4 in.)
MAC
Retimers are
not required
for
10G connections
Today’s 10G Data Center Cabling & Modules
300m
300m MMF, 2km SMF, 10km SMF
10m
10m
10Gbps is now Moving to 25Gbps
25+Gbps serial lane
Supports current 10Gbps and 16Gbps applications with
substantial margin
Backward compatible with SFP form factor
– Same PCB footprint
– Same mating interface
– Same EMI cage dimensions
Full SI test reports available
Tomorrow’s 28G “Top” of Rack Switch
Same Interconnect Form Factors/Port Density
– Increased Performance
28GbE
48 ports of SFP28
144 ports with QSFP28
Tomorrow’s 28G Data Center Interconnects
Switch
Smaller
connector for
higher density
passive copper
interconnects
are under
consideration
Chip to
Module
(4-12 in.)
Retimers are
required
for optical ports
QSFP28
2-10m
Nano
(2-4 in.)
(2-4 in.)
(2-4 in.)
(2-4 in.)
Server
MAC
MAC
MAC
MAC
SFP28 SMT Connectors & Cages
25+Gbps serial lane
Supports current 10Gbps and 16Gbps applications with
substantial margin
Backward compatible with SFP form factor
Same PCB footprint
Same mating interface
Same EMI cage dimensions
Full SI test reports available
SFP28 Stacked Integrated Connectors
Backward compatible with all SFP form factors
• Same mating interface
• Same EMI cage dimensions
• NEW Connector PCB Footprint
Full SI test reports available
SFP28 Product Family
QSFP28 SMT Connectors
25Gbps serial lanes, x4 port system
Uses preferential coupling top and bottom row.
Supports current 10Gbps and 16Gbps applications with substantial margin.
Backward compatible with QSFP form factor
• Same mating interface
• Modified Depth EMI cage dimensions
• Same SMT PCB Footprint, shifted ~ 2.2mm
QSFP28 SMT utilizes preferential coupling to provide a solution for 25 Gbs x4
lane interfaces to support 100G Ethernet, 100G InfiniBand, etc.
Selected as the 4x solution for both FDR and EDR InfiniBand interfaces.
QSFP28 Single & Ganged Cages
Sheet Metal & Die Cast Cage Assemblies
Up to 4 light-pipes per port
QSFP28 Stacked Integrated Connectors
Air Vents
Enhance Cooling
Light
Pipes
EMI Spring Fingers
QSFP28 Product Family
Stacked Integrated Connectors
Belly-to-Belly Cages
Light Pipe &
Thermal Options
Copper & Optical
Loop-backs
Active
Optical Cables
Single SMT Connectors
w/Single & Ganged Cages
Passive
Optical Cables
Pluggable Modules
Passive & Active Copper Cables
SFP28/QSFP28 Summary
SFP28 & QSFP28 upgrades provide substantial margin for
10Gbps and 16Gbps applications
Provides an upgrade path to 25Gbps+
The SFP28 SMT version is a footprint, cage, and mating
interface compatible upgrade
The stacked integrated QSFP28 version is not footprint
compatible but is module/mate interface compatible.
Thermal solution development continues
Issues Going Forward
NRZ or PAM as well as: Faster, Smaller, Hotter - Sooner
Thermals
Time
Data Rate
Density
Non Return to Zero
– sometimes called PAM 2
Classic High Speed digital signal transmission
Today’s products support NRZ signal transmission to
25/28/32 Gbps
Copper cables and connectors are available in a range of
formats and styles
PAM 4
PAM 4 – Pulse Amplitude Modulation
- encodes data in 4 signaling levels
Doubles data content for a given bandwidth, with
additional processing penalty
Today, being used to drive current backplane systems to
25 Gbps
Offers future upgrade path for I/O as well
When applied to 25 Gbps systems
- yields 59 Gbps serial data streams
Under Development
Wider range of cages and thermal solutions
SFP28 Thru-Flow – Shown with Plugs
Under Development
QSFP / SFP
Quad Lane
Single Lane
Quad Lane
Smaller I/O
Density Improvements using Smaller I/O
Huge reduction in board real estate as shown below
Enables shorter trace lengths
Lower height releases more faceplate area for cooling holes
Dual port
100GbE with
QSFP28
Dual port 100GbE
with Nano-Pitch
Dual Port SAS/PCIe
Data Center Interconnects on the Horizon
Optical Engines Provide:
- Infinite Data Center distances
- Are still cost prohibitive
4x100G
4x100G
Optical Engine Architectures
Success of an optical engine architecture requires
a higher density electrical I/O on switch host chips
5cm
Host
Chip
Optical Engine
From an Interconnect Viewpoint
Currently agnostic regarding NRZ vs. PAM 4
Goal is to simply develop technologies that support
higher bandwidth, regardless.
End game – 56 Gb/s NRZ connectors
(double the current bandwidth)
and cables will support PAM 4 as well,
yielding 100 Gbps serial interfaces.
QSFP28 will then support 400 Gbps interfaces!
Actual speeds are approximate, 25/28 are roughly the
same.