Hi Ilya, thank your for your response. Both system were configured for each test I’ve done. On T420 I’ve optimized the kernel following the official Postgres documentation ( http://www.postgresql.org/docs/9.4/static/kernel-resources.html ): kernel.shmmax=68719476736 kernel.shmall=16777216 vm.overcommit_memory=2 vm.overcommit_ratio=90 RAID controllers were configured as following: - Write cache: WriteBack - Read cache: ReadAhead - Disk cache (only T420): disabled to take full advantage of WriteBack cache (BBU is charged and working) - NCQ (only MacMini because it’s a SATA option): enabled (this affects a lot the overall performance) For postgresql.conf: T420 Normal operations autovacuum = on maintenance_work_mem = 512MB work_mem = 512MB wal_buffers = 64MB effective_cache_size = 64GB # this helps A LOT in disk write speed when creating indexes shared_buffers = 32GB checkpoint_segments = 2000 checkpoint_completion_target = 1.0 effective_io_concurrency = 0 # 1 doesn’t make any substantial difference max_connections = 10 # 20 doesn’t make any difference Data loading (same as above with the following changes): autovacuum = off maintenance_work_mem = 64GB MacMini Normal operations autovacuum = on maintenance_work_mem = 128MB work_mem = 32MB wal_buffers = 32MB effective_cache_size = 800MB shared_buffers = 512MB checkpoint_segments = 32 checkpoint_completion_target = 1.0 effective_io_concurrency = 1 max_connections = 20 Data loading (same as above with the following changes): autovacuum = off maintenance_work_mem = 6GB Best regards, Pietro Il giorno 01/apr/2015, alle ore 16:27, Ilya Kosmodemiansky <ilya.kosmodemiansky@xxxxxxxxxxxxxxxxxxxxxxxxx> ha scritto: Hi Pietro, |
