Some basics on the 5010, 5020, 5548P/UP and 5596UP/T. This post is still a work in progress.
######## Nexus 5010 and 5020 ######
Nexus 5010
Physical
1 RU
20 fixed 10G Ethernet
1 slot for GEMs
2 slots for hot swap power supplies
2 slots for fans
Nexus 5020
Physical
2 RU
40 fixed 10G Ethernet
2 slots for GEMs
2 slots for hot swap power supplies
5 slots for fans
GEMs (Gatos Expansion Module)
M1404 - 4 SFP+ and 4 FC
M1600 - 6 SFP+
M1008 - 8 FC
M1060 - 6 FC
5010/5020 limitations/differences
No Fabricpath
FCoE QoS automatic when FCoE feature is enabled
No L3 through the box support
######## Nexus 5548 and 5596 ######
Nexus 5548P
Physical
1 RU
32 fixed 10G Ethernet
Up to 16 Unified ports on expansion module
Nexus 5548UP
Physical
1 RU
32 ports unified
Up to 16 Unified ports on expansion module
Nexus 5596UP
Physical
2 RU
48 fixed Unified ports
Up to 48 Unified ports on expansion module
Nexus 5596T
Physical
2 RU
48 fixed port (32 of 10Gbase-T + 16 SFP+)
Up to 48 Unified ports on expansion module
L3 Daughter Card
All model of the 5548 and 5596 support an L3 daughter card. This card replaces the Layer 2 I/O module on the front of the chassis and provides up to 160 Gbps of L3 forwarding.
Expansion Modules
16 port 1/10 GE and FCoE SFP+
8 port 1/10 GE and FCoE SFP+ with 8 ports FC
16 Unified ports
4 port QSFP for 4 40 GE ports