ape head:
FreeBSD giant-ape1-amd64 10.0-CURRENT FreeBSD 10.0-CURRENT #5 r244369: 
Tue Dec 18 00:19:36 UTC 2012 
root@giant-ape1-amd64:/usr/obj/usr/src/sys/APE  amd64

/usr/local/pgsql on zfs.

[root@giant-ape1-amd64 ~]# bin/run_pgsql.sh 

-----
1
5353.602138
6214.888508
6478.528911
6664.134068
6014.086584
6028.544403
-----
4
25692.860084
25714.526758
25296.986899
25749.967786
25704.991802
25727.973118
-----
8
48101.155901
47940.807539
48235.244476
47670.279626
48039.489365
48908.472941
-----
12
43821.169797
47499.273965
42159.197128
41459.363412
44219.570124
52721.115755
-----
16
26205.145901
26027.411030
26920.026809
24874.158538
26581.949139
24688.309021
-----
18
18780.874039
18614.123332
17954.740303
19034.348778
18578.233253
18358.639250
-----
20
15235.311699
15666.084026
15086.004775
15276.589293
15560.975925
15195.102004
-----
24
12253.479689
11638.657164
11612.195180
11705.924843
11653.165850
11714.695612
-----
32
8508.846452
8091.393793
8537.986307
8362.871800
8243.424316
8325.799265
-----
40
5925.626987
5635.504979
5682.031750
5634.408255
5490.688661
5827.167150
-----
64
2743.421433
2768.876728
2820.745345
2809.738018
2757.709701
2739.097705
-----
80
2302.357787
2309.858829
2316.560458
2314.499198
2275.745850
2284.791772
-----
100
2243.875733
2299.270364
2282.173087
2274.133543
2255.867704
2236.788921