NIC v3.0 Mechanical Discussion 10/27/2017 Joshua Held, Mechanical Engineer, Facebook Yueming Li, Thermal Engineer, Facebook John Fernandes, Thermal Engineer, Facebook Jia Ning, Hardware Engineer, Facebook

NIC v3.0 Configuration Small NIC with Straddle Mount Straddle Connector Chassis Face MB NIC v3.0 Module Snap-in card guides, both sides Small NIC with Straddle Mount

NIC v3.0 Mechanical Goal: Requirements: Develop universal form factors which shall include mechanicals and EMI containment. Requirements: The same NIC design must work in both straddle and right angle configurations NICs might be oriented horizontally or vertically Retention and guidance must work with specified NIC v3.0 MB thicknesses Common mechanical features used across small and large form factors Design of PCB should be flexible enough to support many component and connector configurations without need of mechanical changes Recommended mechanical designs will be included in the specification to simplify and reduce barriers to adoption

Survey Results Requests/Updates Small form factor ports Large form factor ports Partner Top Side KO (mm) Bottom Side KO (mm) Using QSFP Heatsink EMI Concept QSFPs SFPs 1G RJ45 10G RJ45 Fastner Use large NIC A 11 Defer to NIC vendors No Spring Finger 2 2 or 4* 2 or 4 SCR or 1/4 Yes (x32) B 1.9 Not effective 4 4 or 8* 1/4 Maybe (x32) C 11.75 2.2 Yes Latch/Ejct Yes (x24) D 11/11.5* 2/2.25* - E 12.5/25* 2.67/2.0* F 12/24* 2.25/2.67* 1 or 2 1, 2, 4 TBD G 14.47/34.8 2.67/3* 4/6* 6/8* 4/8* SCR Latch/Ejct H 11.5/12.5* 2.67/2.25* No/Yes* Yes (x32,4x8) Current Spec 11.5 ? x24 and x32 * indicates stretch goal 11.5mm 2mm Requests/Updates Added additional survey responses (A-D system vendors, E-H NIC vendors) Current spec proposal can be seen above in the last row Added .25mm thick isolator within 2mm bottom side keep out

Straddle Mount Small/Large 1 Mounting Variants Straddle Mount Small/Large 1 Right Angle (RA) Small/Large 1

Module Versions Small w/ Latch 2x QSFP Large 1 w/ Latch 4x SFP 4x RJ45 Connector 1 Connector 2 Mating Force Unmating Force Small Size 4C + OCP Bay NA 64N (6.5kgf) (14lbf) 20N (2kgf) (4.5lbf) Large Size 1 2C 96N (9.8kgf) (21.6lbf) 30N (3kgf) (6.7lbf) Large Size 2 4C 116N (11.8kgf) (26.1lbf) 37N (3.8kgf) (8.3lbf) 4x RJ45

Top/Bottom Component Placement Sizing Details Available Space PCB Size Top/Bottom Component Placement Routing Inner Layers Small Size 76x115 72x109 Large Size 1 120x115 116x109 Large Size 2 142x115 138x109 2mm card guide keep out - 4mm to width (card guide) - 6mm to length (edge connector) 2mm card guide keep out Requests/Updates Large Size 2 has been met with some opposition due to overall width. We would appreciate any thoughts on this. Is 142mm width not feasible? In regards to the above form factors. Is this enough usable space for expected configurations?

RJ45 Issues Delta and Luxshare have 1x4 RJ45 sink mount designs available at 10mm height Requests/Updates Redesigned the faceplate with hems top and bottom that contact RJ45 grounding fingers, and provided stiff rib opposing grounding finger pressure Concern: if we go below 11.5mm we will be forced to a single material thickness which will cause upper flange to bow significantly in the center Need to verify that 1x2 RJ45s are available in the same height.

Straddle Mount Small/Large Vertical Stack-up 12mm 2.25mm Straddle Mount Small/Large 12mm 2.25mm Right Angle (RA) Small/Large

Next Steps Review DFM with vendors Continue concept development Collect feedback on current spec configuration Continue to close on keep outs, board size, stack up heights, EMI shielding, connector options