On Sun, Sep 18, 2011 at 10:07 AM, Gong Ding <span dir="ltr"><<a href="mailto:gdiso@ustc.edu">gdiso@ustc.edu</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div> <br></div><blockquote style="padding-left:5px;margin-left:5px;border-left:#a0c6e5 2px solid;margin-right:0px"><div class="im">2011/9/18 Gong Ding <span dir="ltr"><<a href="mailto:gdiso@ustc.edu" target="_blank">gdiso@ustc.edu</a>></span><br>
</div><div class="gmail_quote"><div class="im"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi,<br>
I always meed some linear system with condition number near 1e10, the ksp solver (BCGSL + ASM + ILU(1))with double presision<br>
seems painful to convergence.<br></blockquote><div><br></div><div>Higher precision is unlikely to affect the convergence rate. It might help with loss of orthogonality.</div></div><div><br>Do you mean GMRES-like method will be <font>benefited</font> from float 128?<br>
</div></div></blockquote></blockquote><div>My guess is no, but it is possible.</div><div><br></div><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<blockquote style="padding-left:5px;margin-left:5px;border-left:#a0c6e5 2px solid;margin-right:0px"><div class="gmail_quote"><div></div><div class="im"><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Will float 128 helps in this situation?<br>
And how about the performance degenerate for float 128 under i.e. XEON 5620 CPU compared with double?<br>
<br>
Thanks<br>
<font color="#888888">Gong Ding<br>
<br>
</font></blockquote></div></div><div class="im"><br><br clear="all"><div><br></div>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener<br>
</div></blockquote><span></span></blockquote></div><br><br clear="all"><div><br></div>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener<br>