Cisco Aironet 3700 Series Deployment Manual page 7

Cisco Aironet Series 3700 Access Point
Figure 8 ClientLink Feature Comparison
Both, the AP 3700 and AP 3600 support a 4x4:3 architecture. However, the AP 3600 with the module
only supports 11ac in a 3x3:3 mode and lacks the ability to beamform AC clients beyond 7 clients at a
time whereas, the AP 3700 can beamform 128 clients per radio interface.
Cisco Aironet Series 2700/3700 Access Points Deployment Guide
7