Обсуждение: Surprizing performances for Postgres on Centrino
Hi, These last two days, I have some troubles with a very strange phenomena: I have a 400 Mb database and a stored procedure written in perl which call 14 millions times spi_exec_query (thanks to Tom to fix the memory leak ;-) ). On my laptop whith Centrino 1.6 GHz, 512 Mb RAM, - it is solved in 1h50' for Linux 2.6 - it is solved in 1h37' for WXP Professionnal (<troll on> WXP better tan Linux ;-) <troll off>) On a Desktop with PIV 2.8 GHz, - it is solved in 3h30 for W2K On a Desktop with PIV 1.8 GHz, two disks with data and index's on each disk - it is solved in 4h for W2K I test CPU, memory performance on my laptop and it seems that the performances are not perfect except for one single test: String sort. So, it seems that for my application (database in memory, 14 millions of very small requests), Centrino (aka Pentium M) has a build-in hardware to boost Postgres performance :-) Any experience to confirm this fact ? Some tips to speed up Postgres on non-Centrino processors ? -- Jean-Max Reymond CKR Solutions Open Source Nice France http://www.ckr-solutions.com
On 7/7/05, Jean-Max Reymond <jmreymond@gmail.com> wrote: > On my laptop whith Centrino 1.6 GHz, 512 Mb RAM, > - it is solved in 1h50' for Linux 2.6 > - it is solved in 1h37' for WXP Professionnal (<troll on> WXP better > tan Linux ;-) <troll off>) [...] > I test CPU, memory performance on my laptop and it seems that the > performances are not perfect except for one single test: String sort. Well, Pentium 4 is not the most efficient processor around (despite all the advertisiing and all the advanced hyper features). Sure it reaches high GHz rates, but that's not what matters the most. This is why AMD stopped giving GHz ratings and instead uses numbers which indicate how their processor relate to Pentium 4s. For instance AMD Athlon XP 1700+ is running at 1.45 GHz, but competes with Pentium 4 1.7 GHz. Same is with Intels Pentium-III line (which evolved into Pentium-M Centrino actually). Like AMD Athlon, Pentium-M is more efficient about its clockspeed than Pentium 4. In other words, you shouldn't compare Pentium 4 and Pentium-M clock-by-clock. Pentium 4 just needs more GHz to do same job as Pentium-M or Athlon. If you want to get some better (more technical) information, just google around for reviews and articles. There are plenty of them recently since Apple intends to use Pentium-M as their future platform, at least for notebooks. As for technical stuff, for instance look at: http://www.tomshardware.com/howto/20050621/37watt-pc-02.html What really is interesting is the performance difference between WXP and L26... Are you sure they use exactly the same config parameters (shared buffers) and have similar statistics (both VACUUM ANALYZEd recently)? Regards, Dawid
On Thu, Jul 07, 2005 at 03:48:06PM +0200, Dawid Kuroczko wrote: > This is why AMD stopped giving GHz ratings and instead uses numbers > which indicate how their processor relate to Pentium 4s. For instance > AMD Athlon XP 1700+ is running at 1.45 GHz, but competes with > Pentium 4 1.7 GHz. Actually, the XP ratings are _Athlon Thunderbird_ ratings, not P4 ratings. At least they were intended to be that originally :-) /* Steinar */ -- Homepage: http://www.sesse.net/
On Thu, Jul 07, 2005 at 02:49:05PM +0200, Jean-Max Reymond wrote: > Hi, > These last two days, I have some troubles with a very strange phenomena: > I have a 400 Mb database and a stored procedure written in perl which > call 14 millions times spi_exec_query (thanks to Tom to fix the memory > leak ;-) ). > On my laptop whith Centrino 1.6 GHz, 512 Mb RAM, > - it is solved in 1h50' for Linux 2.6 > - it is solved in 1h37' for WXP Professionnal (<troll on> WXP better > tan Linux ;-) <troll off>) > On a Desktop with PIV 2.8 GHz, > - it is solved in 3h30 for W2K > On a Desktop with PIV 1.8 GHz, two disks with data and index's on each disk > - it is solved in 4h for W2K Do you have the same locale settings on all of them? -- Alvaro Herrera (<alvherre[a]alvh.no-ip.org>) "We are who we choose to be", sang the goldfinch when the sun is high (Sandman)
On 7/7/05, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote: > > Do you have the same locale settings on all of them? > interressant: UNICODE on the fast laptop SQL_ASCII on the slowest desktops. is UNICODE database faster than SQL_ASCII ? -- Jean-Max Reymond CKR Solutions Open Source Nice France http://www.ckr-solutions.com
Jean-Max Reymond wrote: > On 7/7/05, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote: > > >>Do you have the same locale settings on all of them? >> > > > interressant: > UNICODE on the fast laptop > SQL_ASCII on the slowest desktops. > is UNICODE database faster than SQL_ASCII ? That's your encoding (character-set). Locale is something like "C" or "en_US" or "fr_FR". -- Richard Huxton Archonet Ltd