<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1487163772805_3481"><span id="yui_3_16_0_ym19_1_1487163772805_3568">I think the chapter 4 of the user manual more or less answers my first question already ...</span></div><div></div><div id="yui_3_16_0_ym19_1_1487163772805_3569"> </div><div class="signature" id="yui_3_16_0_ym19_1_1487163772805_3570">rgds<br>lixin</div> <div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 16px;"> <div dir="ltr"><font size="2" face="Arial"> On Wednesday, 15 February 2017, 14:40, lixin chu <lixin_chu@yahoo.com> wrote:<br></font></div> <br><br> <div class="y_msg_container"><div id="yiv4047212939"><div><div style="color:#000;background-color:#fff;font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif;font-size:13px;"><div id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_2863"><span>Hello,</span></div><div id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_2862">New to PETSc, appreciate any help - </div><div id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_2861"><br></div><div id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_2859" dir="ltr">I have done some experiment with MUMPS (the direct solver for sparse matrix), and very interested to try out PETSc now. I have a large sparse symmetric matrix (3 millions x 3 millions, complex data type).</div><div id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_2859"><br></div><div id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_2859" dir="ltr">Some questions I have:<br>- I am assuming that I should select one algorithm of "<span style="background-color:rgb(213, 234, 255);font-size:medium;" id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_4807">Krylov methods", </span>which algorithm is a good option, GMRES, CG, or others ? (I am not a domain expert, but helping developing a program to test the matrix). </div><div id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_2859" dir="ltr">- do all the algorithms support distributed architecture (multiple machines, multiple cores)</div><div id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_4596" dir="ltr">- are there any performance test data ? (total run time for example)</div><div id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_4670"><br></div><div></div><div id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_2858"> </div><div class="yiv4047212939signature" id="yiv4047212939yui_3_16_0_ym19_1_1487140151116_2857">thank you very much,<br>LX</div></div></div></div><br><br></div> </div> </div> </div></div></body></html>