On 24/03/17 14:17, Erik Schnetter wrote:
On Fri, Mar 24, 2017 at 8:43 AM, Eloisa Bentivegna <eloisa.bentivegna@ct.infn.it mailto:eloisa.bentivegna@ct.infn.it> wrote:
Hi all, still on the KNL topic, I realize there was a question I ignored, and which perhaps is worth pursuing. On 01/03/17 21:43, Ian Hinder wrote: > Eloisa: does Carpet report the vector size of the KNL as 8? From the > wikipedia entry, I would expect that to be the case, but I think you > mentioned to me that it was reporting 4. That's correct. In my output I find: =============================================================== INFO (Vectors): Using vector size 4 for architecture AVX (64-bit precision) =============================================================== Is this not supposed to be so? And in this case, is there anything I can do about it?You should see a vector size of 8, and a message containing "AVX512 (64-bit precision)". If you do not do this, then there is a problem with the compiler options -- this decision is made at compile time. You might need to specify "-march=knl" to GCC, or a similar option to the Intel compiler, or you could build on a KNL node and use "-march=native" or "-xHost".
Hi all,
I have now tried all of these options and continue getting the message
=============================================================== INFO (Vectors): Using vector size 4 for architecture AVX (64-bit precision) ===============================================================
Can linking to system libraries compiled for the BDW architecture lead to this message, even if the Cactus executable itself was build on a KNL with the KNL flags?
In any case, I have created a pull request of Simfactory with the KNL configuration I am using now. At least it's a starting point.
Best, Eloisa