Vacumm full done after each run.
pg_resetlog run between each server start

Scaling factor: 10
Initialization time: 
real    1m42.282s
user    0m1.787s
sys     0m0.121s

Kernel 2.6.0-test4
Effective cache size 38400 (300MB)
checkpoint segments=6

1)Shared buffers 1000

pgbench -c5 -t100 test1 
tps = 131.962542 (including connections establishing)
tps = 134.418358 (excluding connections establishing)

pgbench -c5 -t1000 test1
tps = 79.301493 (including connections establishing)
tps = 79.393258 (excluding connections establishing)

pgbench -c10 -t100 test1
tps = 64.917044 (including connections establishing)
tps = 65.438067 (excluding connections establishing)

pgbench -c10 -t1000 test1
tps = 66.135615 (including connections establishing)
tps = 66.193039 (excluding connections establishing)

2) Shared buffers 2000

pgbench -c5 -t100 test1
tps = 135.598994 (including connections establishing)
tps = 138.296634 (excluding connections establishing)

pgbench -c5 -t1000 test1
tps = 81.331678 (including connections establishing)
tps = 81.425369 (excluding connections establishing)

pgbench -c10 -t100 test1
tps = 116.524476 (including connections establishing)
tps = 118.388407 (excluding connections establishing)

pgbench -c10 -t1000 test1
tps = 64.659894 (including connections establishing)
tps = 64.719829 (excluding connections establishing)

3) Shared buffers 3000

pgbench -c5 -t100 test
tps = 132.489569 (including connections establishing)
tps = 135.177003 (excluding connections establishing)

pgbench -c5 -t1000 test
tps = 70.272855 (including connections establishing)
tps = 70.343452 (excluding connections establishing)

pgbench -c10 -t100 test
tps = 121.624524 (including connections establishing)
tps = 123.549086 (excluding connections establishing)

pgbench -c10 -t1000 test
tps = 64.124644 (including connections establishing)
tps = 64.183736 (excluding connections establishing)

4) noatime enabled Shared buffers 3000

pgbench -c5 -t100 test
tps = 90.850600 (including connections establishing)
tps = 92.053686 (excluding connections establishing)

pgbench -c5 -t1000 test
tps = 92.209724 (including connections establishing)
tps = 92.329682 (excluding connections establishing)

pgbench -c10 -t100 test
tps = 79.264231 (including connections establishing)
tps = 80.145448 (excluding connections establishing)

pgbench -c10 -t1000 test
tps = 70.439082 (including connections establishing)
tps = 70.506189 (excluding connections establishing)