VMware: up to 200 virtual desktops/node
Citrix: up to 90 virtual desktops/node
Details
VMware Horizon 7.0: Load bearing number is based on Login VSI tests performed on all-flash rack servers using 2vCPU Windows 7 desktops and the Knowledge Worker profile.
Citrix XenDesktop 7.9: Load bearing number is based on Login VSI tests performed on hybrid VxRail 160 appliances using 2vCPU Windows 7 desktops and the Knowledge Worker profile.
For detailed information please read the corresponding whitepapers.