I just made another test with a second Gentoo machine:
Pentium 4 3.0Ghz Prescott
GCC 4.1.1
Glibc 2.4
PostgreSQL 8.1.5
Kernel 2.6.17
Same postgresql.conf as yesterday's.
First test
==========
GLIBC: -O2 -march=i686
PostgreSQL: -O2 -march=i686
Results: 974.638731 975.602142 975.882051 969.142503 992.914167
983.467131 983.231575 994.901330 970.375221 978.377467
Average (error): 980 tps (13 tps)
Second test
===========
GLIBC: -O2 -march=i686
PostgreSQL: -O2 -march=prescott
Results: 988.319643 976.152973 1006.482553 992.431322 983.090838
992.674065 989.216746 990.897615 987.129802 975.907955
Average (error): 988 tps (15 tps)
Third test
==========
GLIBC: -O2 -march=prescott
PostgreSQL: -O2 -march=i686
Results: 969.085400 966.187309 994.882325 968.715150 956.766771
970.151542 960.090571 967.680628 986.568462 991.756520
Average (error): 973 tps (19 tps)
Forth test
==========
GLIBC: -O2 -march=prescott
PostgreSQL: -O2 -march=prescott
Results: 980.888371 978.128269 969.344669 978.021509 979.256603
993.236457 984.078399 981.654834 976.295925 969.796277
Average (error): 979 tps (11 tps)
The results showed no significant change. The conclusion of today's
test would be that there are no improvement at PostgreSQL when using
-march=prescott.
I only see 3 diferences between yesterday's server and today's: the
kernel version (y: 2.6.18, t:2.6.17), the server uses an IDE harddrive
(yesterday was SATA), and the gcc version (3.4.6 -> 4.1.1).
I don't know why yesterday we had improved and today we had not.
Best
Daniel
On 12/12/06, Daniel van Ham Colchete <daniel.colchete@gmail.com> wrote:
> I'm making some other tests here at another hardware (also Gentoo). I
> found out that PostgreSQL stops for a while if I change the -t
> parameter on bgbench from 600 to 1000 and I have ~150 tps instead of
> ~950tps.
