Hi Tigran, my debugging tips:
>Some technical details: >Host: rhel 6.5 2.6.32-431.23.3.el6.x86_64 >256 GB RAM, 40 cores, Intel(R) Xeon(R) CPU E5-2660 v2 @ 2.20GHz >2x160GB PCIe SSD DELL_P320h-MTFDGAL175SAH As I know PCIe SSD DELL_P320h = Micron P320h ( http://www.micron.com/products/solid-state-storage/enterprise-pcie-ssd/p320h-25-inch-pcie-ssd ) so my suggestions: #1. Check/Upgrade to the latest Micron kernel driver ** https://www.google.com/search?q=p420m_p320h_hhhl_installation_guide%2520_.pdf *** "RHEL version 6.1–6.5: kmod-mtip32xx-<version>.el6.x86_64_rhel6ux.rpm" #2. And check "Technical Note P320h/P420m SSD Performance Optimization and Testing" ** https://www.google.com/search?q=tnfd15_micron_pciessd_performance_testing.pdf strange : **** "Table 1: PCIe SSD Hardware and Software Requirements " ***** "Processors with clock speeds greater than 3 GHz (recommended for best performance)" * ( you have now: 2.20GHz )* ***** "*Up to 8 CPU cores *(logical + physical) with hyperthreading (recommended)"* ( you have 20! )* so check performance with* "Turning off Hyper-Threading" * Imre 2014-09-24 15:03 GMT+02:00 Mkrtchyan, Tigran <tigran.mkrtch...@desy.de>: > > With pg_test_timing I can see, that overhead is 48 nsec on my server and > 32 nsec on the laptop. > what makes this difference and have it any influence on the overall > performance? > > Tigran. > > ----- Original Message ----- > > From: "Mark Kirkwood" <mark.kirkw...@catalyst.net.nz> > > To: "Tigran Mkrtchyan" <tigran.mkrtch...@desy.de>, "Merlin Moncure" < > mmonc...@gmail.com> > > Cc: "postgres performance list" <pgsql-performance@postgresql.org> > > Sent: Wednesday, September 24, 2014 12:04:12 PM > > Subject: Re: [PERFORM] postgres 9.3 vs. 9.4 > > > > On 24/09/14 21:23, Mkrtchyan, Tigran wrote: > > > Hi Merlin et al. > > > > > > after building postgres 9.4 myself from sources I get the same > performance > > > as > > > with 9.3. The difference was in the value of debug_assertions setting. > > > > > > Now the next step. Why my 3 years old laptop gets x1.8 times more tps > than > > > my one month old server? > > > And Mark Kirkwood's desktop gets x2 times more tps as well? Is there > some > > > special optimization > > > for i7 which does not work with Intel(R) Xeon(R) CPU E5-2660? > > > > > > > > > > Yes - firstly, nicely done re finding the assertions (my 9.4 beta2 was > > built from src - never thought to mention sorry)! > > > > I'd guess that you are seeing some bios setting re the p320 SSD - it > > *should* be seriously fast...but does not seem to be. You could try > > running some pure IO benchmarks to confirm this (e.g fio). Also see if > > the manual for however it is attached to the system allows for some > > optimized-for-ssd settings that tend to work better (altho these usually > > imply the drive is plugged into an adapter card of some kind - mind you > > your p320 *does* used a custom connector that does 2.5" SATA to PCIe > > style interconnect so I'd look to debug that first). > > > > Cheers > > > > Mark > > > > > > > -- > Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance >
