HPE ProLiant DL385 Gen10, 2xAMD EPYC 7702, 2.0 GHz, 2S/128C/256T, 1024 GB, WS2019, MS SQL Server 2017 = 45,600 Users
For comparison:
HPE ProLiant DL385 Gen10, 2xAMD EPYC 7601, 2.2 GHz, 2S/64C/128T, 1024 GB, WS2012, MS SQL Server 2012 = 23,820 Users
HPE Proliant DL380 Gen10, 2xIntel Xeon Pt 8280L, 2.7 GHz, 2S/56C/112T, 768 GB, WS2016DE, MS SQL Server 2012 = 29,231 Users
Other OS/Db:
Dell EMC PowerEdge R740xd, 2xIntel Xeon Pt 8280, 2.7 GHz, 2S/56C/112T, 768 GB, SLES 15, SAP ASE 16 = 35,505 Users
Very expensive:
FUJITSU Server PRIMERGY RX4770 M5, 4xXeon Pt 8280, 2.7 GHz, 4S/112C/224T, 11536 GB (??? - mistake?) , WS2016DE, MS SQL Server 2012 = 57,500 Users
IBM Power System E980, 16xPOWER9, 3.9 GHz, 16S/192Cs/1536T, 8192 GB, AIX 7.2, Db2 10.5 = 205,000 Users
Fujitsu SPARC M10-4S, 32xSPARC64 X+, 3.7 GHz, 32S/512C/1024T, 8192 GB, Solaris 11, Oracle 12c = 153,050 Users