matmult

A*B on M1

dimension	dense	sparse (10%)	sparse (50%)
10	0.000012	0.000038	0.000076
100	0.000224	0.000897	0.002076
1000	0.074843	0.157203	1.148960
2000	0.484162	0.880995	8.841200

A*B on xeon E5-2658

dimension	dense	sparse (10%)	sparse (50%)
10	0.000008	0.000011	0.000027
100	0.000717	0.000388	0.000855
1000	0.219490	0.098935	0.281870
2000	1.488919	0.510150	2.017370

(units are in seconds).