Thread: Faster GPU-ECM with CGBN View Single Post
 2021-09-01, 15:02 #42 bsquared     "Ben" Feb 2007 3,617 Posts I re-cloned the gpu_integration branch to capture the latest changes and went through the build process with the following caveats: specifying --with-gmp together with --with-cgbn-include doesn't work. I had to use the system default gmp (6.0.0). With compute 70 I still have to replace __any with __any_sync(__activemask() on line 10 of cude_kernel_default.cu building with gcc I get this error in cgbn_stage1.cu: cgbn_stage1.cu(654): error: initialization with "{...}" is not allowed for object of type "const std::vector>" I suppose I need to build with g++ instead? Anyway I can get past all of that and get a working binary and the cpu usage is now much lower. But now the gpu portion appears to be about 15% slower? Before: Code: Input number is 2^997-1 (301 digits) Computing 5120 Step 1 took 75571ms of CPU time / 129206ms of GPU time Throughput: 39.627 curves per second (on average 25.24ms per Step 1) New clone: Code: Input number is 2^997-1 (301 digits) Computing 5120 Step 1 took 643ms of CPU time / 149713ms of GPU time Throughput: 34.199 curves per second (on average 29.24ms per Step 1) Anyone else seeing this?