 of a GPU-enabled test program part three.</span></div><!--tex4ht:label?: x16-15003r7 -->
                                                                               

                                                                               
   </div><hr class="endfloat" />
<!--l. 592--><p class="indent" >   <span 
class="cmr-12">It is very important to employ smoothers and coarsest solvers that are suited to the</span>
<span 
class="cmr-12">GPU, i.e. methods that do NOT employ triangular system so