kaivalnp commented on PR #14178: URL: https://github.com/apache/lucene/pull/14178#issuecomment-2622538569
> Since Faiss uses multithreading by default, we cannot compare with Lucene Ah nice catch, the number of threads used by both may be different.. I'm not sure how many threads were used by Faiss above, but the number of threads used by Lucene are specified [here](https://github.com/mikemccand/luceneutil/blob/9764dffb3e00fc37a9edb4a55381010d4c60c26c/src/python/knnPerfTest.py#L65-L66) (I didn't change these) I set `$OMP_NUM_THREADS=4` (from the [link](https://github.com/facebookresearch/faiss/wiki/Threads-and-asynchronous-calls#internal-threading) you sent) to keep the number of threads same in both: Lucene: ``` recall latency (ms) nDoc topK fanout maxConn beamWidth quantized index s index docs/s force merge s num segments index size (MB) vec disk (MB) vec RAM (MB) 0.811 1.439 200000 100 50 32 200 no 51.98 3847.63 0.00 1 237.75 228.882 228.882 ``` Faiss: ``` recall latency (ms) nDoc topK fanout maxConn beamWidth quantized index s index docs/s force merge s num segments index size (MB) vec disk (MB) vec RAM (MB) 0.810 1.110 200000 100 50 32 200 no 15.92 12565.18 41.44 1 511.21 228.882 228.882 ``` Not as high as 10x anymore, but it is still \~3x faster > Does that mean that you indexed with `-numIndexThreads=1` for the Lucene run? This was [set to `8`](https://github.com/mikemccand/luceneutil/blob/9764dffb3e00fc37a9edb4a55381010d4c60c26c/src/python/knnPerfTest.py#L183) for both runs (I didn't change the default value) -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org
