Hi Niall, even if disk seems not an issue check your linux disk settings with hdparm (if you are on a pc). May be the windows driver is using DMA and linux PIO or something similar. HTH Giovanni > I'm - not for the first time bemused - I wonder if anyone can (after > fighting past the screwed up formatting that blogger gave me) shed > light on the results that I have on my site for running identical SQL > on identical hardware (the same machine actually) under Windows XP sp2 > and Fedora Core 3 linux. (incidentally FC3 passed the certified os > checks on install). > > briefly the test is > > create a table with 20k rows. > insert into the table all the rows from itself 6 times > > tune based on the response time (I've used tkprof to generate the > response time profile). > > My linux box seems to be stuck waiting on log_buffer space and whilst > throwing memory at it has helped (I've gone as high as 8mb log buffer > and to my surprise got some marginal improvement over the 1mb I've > documented) it is still half the speed of the same hardware running > windows. some mistake surely. > > My kernel parameters are > > kernel.shmall = 2097152 > kernel.shmmax = 2147483648 > kernel.shmmni = 4096 > kernel.sem = 250 32000 100 128 > fs.file-max = 65536 > net.ipv4.ip_local_port_range = 1024 65000 > > > > because I followed John Smiley's article for the install > > (http://www.oracle.com/technology/pub/articles/smiley_10gdb_install.html) > -- ---------------------------------------- Giovanni Cuccu Sw Engineer@xxxxxxxxxxx Dianoema S.p.A. Via de' Carracci 93 40131 Bologna Tel: 051-7098211 051-4193911 e-mail:gcuccu@xxxxxxxxxxx ---------------------------------------- No man does it all by himself, I said young man, put your pride on the shelf ---------------------------------------- -- //www.freelists.org/webpage/oracle-l