Hopefully I will be able to post results shortly on 2P4C performance. ~ Sourajit
On Mon, Jun 10, 2013 at 2:20 AM, Toke Eskildsen <t...@statsbiblioteket.dk>wrote: > Sourajit Basak [sourajit.ba...@gmail.com]: > > Does more processors with less cores or less processors with more cores > > i.e. which of 4P2C or 2P4C has best cost per query ? > > I have not tested that, so everything I say is (somewhat qualified) > guesswork. > > Assuming a NUMA architecture, my guess is that 2P4C would be superior to > 4P2C. Solr utilizes both disk caching and explicit caching on the JVM heap > making memory access quite heavy; the less processors, the higher the > chance that the memory will be controlled by the processor running the > given search thread. I am by no means a NUMA expert, but it seems that > requests for memory controlled by another processor takes about twice as > long as local memory. > > Our machine is a NUMA dual processor and if I can find the time, I would > love to perform some tests on how that part influences query time. If would > be interesting to lock usage to 2 cores on each processor vs. 4 cores on > the same processor. The tricky part is to ensure that RAM is fully > controlled by the single processor in the second test, including the disk > cache. > > Regards, > Toke Eskildsen
