Circuit simulation matrix from Emrah Acar, IBM Austin. High degree of coupling. From Emrah Acar, IBM Research-Austin this matrix failed in umd4[umfpack4.0], ma28 takes forever, sparse1.3 is slower than umd2, haven't tested in 4.3. The matrix is from transient simulation of a timing path. The circuit contains a high level of coupling. For more info contact Emrah Acar, emrah (at sign) us dot ibm dotcom IBM Austin Research Lab Results from Tim Davis: On a 3.2Ghz Pentium 4, UMFPACK v4.0 takes 7.4 seconds (backslash in MATLAB 6.5). UMFPACK v4.3 takes 0.20 seconds.