All unique:
       Rate    u1    u2    u3    u4
u1  15504/s    --  -75%  -95%  -95%
u2  62910/s  306%    --  -78%  -78%
u3 289343/s 1766%  360%    --   -1%
u4 291910/s 1783%  364%    1%    --

Not Unique:
       Rate    u1    u2    u3    u4
u1  17396/s    --  -72%  -98%  -98%
u2  62887/s  262%    --  -92%  -92%
u3 748300/s 4202% 1090%    --   -5%
u4 783739/s 4405% 1146%    5%    --