Disappointing speed with ZFS

Hello.

I am trying to use ZFS to store my torrent downloads. I noticed that  
hashing in rtorrent works 10 times slower than the same disk with UFS.

I've done tuning as described in WIKI:

vm.kmem_size_max="1073741824"
vm.kmem_size="1073741824"

kern.maxvnodes=800000

My DMESG:

Copyright (c) 1992-2008 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
         The Regents of the University of California. All rights  
reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.
FreeBSD 7.0-PRERELEASE #1: Wed Feb  6 15:39:32 MSK 2008
     lexa_at_alpha.lexasoft.ru:/usr/obj/usr/src/sys/ALPHA
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Genuine Intel(R) CPU            2160  _at_ 1.80GHz (1795.51-MHz K8- 
class CPU)
   Origin = "GenuineIntel"  Id = 0x6f2  Stepping = 2
    
Features 
= 
0xbfebfbff 
< 
FPU 
,VME 
,DE 
,PSE 
,TSC 
,MSR 
,PAE 
,MCE 
,CX8 
,APIC 
,SEP 
,MTRR 
,PGE 
,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
   Features2=0xe39d<SSE3,RSVD2,MON,DS_CPL,EST,TM2,SSSE3,CX16,xTPR,PDCM>
   AMD Features=0x20100800<SYSCALL,NX,LM>
   AMD Features2=0x1<LAHF>
   Cores per package: 2
usable memory = 4280516608 (4082 MB)
avail memory  = 4125683712 (3934 MB)
ACPI APIC Table: <PTLTD          APIC  >
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
  cpu0 (BSP): APIC ID:  0
  cpu1 (AP): APIC ID:  1
ioapic0 <Version 2.0> irqs 0-23 on motherboard
ioapic1 <Version 2.0> irqs 24-47 on motherboard
kbd1 at kbdmux0
ath_hal: 0.9.20.3 (AR5210, AR5211, AR5212, RF5111, RF5112, RF2413,  
RF5413)
hptrr: HPT RocketRAID controller driver v1.1 (Feb  6 2008 15:37:30)
acpi0: <PTLTD   RSDT> on motherboard
acpi0: [ITHREAD]
acpi0: Power Button (fixed)
Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x1008-0x100b on acpi0
cpu0: <ACPI CPU> on acpi0
est0: <Enhanced SpeedStep Frequency Control> on cpu0
est: CPU supports Enhanced Speedstep, but is not recognized.
est: cpu_vendor GenuineIntel, msr 928092806000928
device_attach: est0 attach returned 6
p4tcc0: <CPU Frequency Thermal Control> on cpu0
cpu1: <ACPI CPU> on acpi0
est1: <Enhanced SpeedStep Frequency Control> on cpu1
est: CPU supports Enhanced Speedstep, but is not recognized.
est: cpu_vendor GenuineIntel, msr 928092806000928
device_attach: est1 attach returned 6
p4tcc1: <CPU Frequency Thermal Control> on cpu1
pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0
pci0: <ACPI PCI bus> on pcib0
pcib1: <ACPI PCI-PCI bridge> irq 16 at device 1.0 on pci0
pci1: <ACPI PCI bus> on pcib1
pcib2: <ACPI PCI-PCI bridge> irq 17 at device 28.0 on pci0
pci9: <ACPI PCI bus> on pcib2
pcib3: <ACPI PCI-PCI bridge> at device 0.0 on pci9
pci10: <ACPI PCI bus> on pcib3
pcib4: <ACPI PCI-PCI bridge> irq 17 at device 28.4 on pci0
pci13: <ACPI PCI bus> on pcib4
em0: <Intel(R) PRO/1000 Network Connection Version - 6.7.3> port  
0x4000-0x401f mem 0xe0200000-0xe021ffff irq 16 at device 0.0 on pci13
em0: Using MSI interrupt
em0: Ethernet address: 00:30:48:8f:78:ca
em0: [FILTER]
pcib5: <ACPI PCI-PCI bridge> irq 16 at device 28.5 on pci0
pci14: <ACPI PCI bus> on pcib5
em1: <Intel(R) PRO/1000 Network Connection Version - 6.7.3> port  
0x5000-0x501f mem 0xe0300000-0xe031ffff irq 17 at device 0.0 on pci14
em1: Using MSI interrupt
em1: Ethernet address: 00:30:48:8f:78:cb
em1: [FILTER]
uhci0: <UHCI (generic) USB controller> port 0x3000-0x301f irq 23 at  
device 29.0 on pci0
uhci0: [GIANT-LOCKED]
uhci0: [ITHREAD]
usb0: <UHCI (generic) USB controller> on uhci0
usb0: USB revision 1.0
uhub0: <Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1> on usb0
uhub0: 2 ports with 2 removable, self powered
uhci1: <UHCI (generic) USB controller> port 0x3020-0x303f irq 19 at  
device 29.1 on pci0
uhci1: [GIANT-LOCKED]
uhci1: [ITHREAD]
usb1: <UHCI (generic) USB controller> on uhci1
usb1: USB revision 1.0
uhub1: <Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1> on usb1
uhub1: 2 ports with 2 removable, self powered
uhci2: <UHCI (generic) USB controller> port 0x3040-0x305f irq 18 at  
device 29.2 on pci0
uhci2: [GIANT-LOCKED]
uhci2: [ITHREAD]
usb2: <UHCI (generic) USB controller> on uhci2
usb2: USB revision 1.0
uhub2: <Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1> on usb2
uhub2: 2 ports with 2 removable, self powered
uhci3: <UHCI (generic) USB controller> port 0x3060-0x307f irq 16 at  
device 29.3 on pci0
uhci3: [GIANT-LOCKED]
uhci3: [ITHREAD]
usb3: <UHCI (generic) USB controller> on uhci3
usb3: USB revision 1.0
uhub3: <Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1> on usb3
uhub3: 2 ports with 2 removable, self powered
ehci0: <Intel 82801GB/R (ICH7) USB 2.0 controller> mem  
0xe0000000-0xe00003ff irq 23 at device 29.7 on pci0
ehci0: [GIANT-LOCKED]
ehci0: [ITHREAD]
usb4: EHCI version 1.0
usb4: companion controllers, 2 ports each: usb0 usb1 usb2 usb3
usb4: <Intel 82801GB/R (ICH7) USB 2.0 controller> on ehci0
usb4: USB revision 2.0
uhub4: <Intel EHCI root hub, class 9/0, rev 2.00/1.00, addr 1> on usb4
uhub4: 8 ports with 8 removable, self powered
pcib6: <ACPI PCI-PCI bridge> at device 30.0 on pci0
pci15: <ACPI PCI bus> on pcib6
vgapci0: <VGA-compatible display> port 0x6000-0x60ff mem  
0xe8000000-0xefffffff,0xe0400000-0xe040ffff irq 16 at device 0.0 on  
pci15
isab0: <PCI-ISA bridge> at device 31.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <Intel ICH7 UDMA100 controller> port  
0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0x30a0-0x30af at device 31.1 on pci0
ata0: <ATA channel 0> on atapci0
ata0: [ITHREAD]
ata1: <ATA channel 1> on atapci0
ata1: [ITHREAD]
atapci1: <Intel ICH7 SATA300 controller> port 0x30e8-0x30ef, 
0x30dc-0x30df,0x30e0-0x30e7,0x30d8-0x30db,0x30b0-0x30bf mem  
0xe0000400-0xe00007ff irq 19 at device 31.2 on pci0
atapci1: [ITHREAD]
ata2: <ATA channel 0> on atapci1
ata2: [ITHREAD]
ata3: <ATA channel 1> on atapci1
ata3: [ITHREAD]
pci0: <serial bus, SMBus> at device 31.3 (no driver attached)
acpi_button0: <Power Button> on acpi0
atkbdc0: <Keyboard controller (i8042)> port 0x60,0x64 irq 1 on acpi0
atkbd0: <AT Keyboard> irq 1 on atkbdc0
kbd0 at atkbd0
atkbd0: [GIANT-LOCKED]
atkbd0: [ITHREAD]
sio0: configured irq 4 not in bitmap of probed irqs 0
sio0: port may not be enabled
sio0: configured irq 4 not in bitmap of probed irqs 0
sio0: port may not be enabled
sio0: <16550A-compatible COM port> port 0x3f8-0x3ff irq 4 flags 0x10  
on acpi0
sio0: type 16550A
sio0: [FILTER]
sio1: configured irq 3 not in bitmap of probed irqs 0
sio1: port may not be enabled
sio1: configured irq 3 not in bitmap of probed irqs 0
sio1: port may not be enabled
sio1: <16550A-compatible COM port> port 0x2f8-0x2ff irq 3 on acpi0
sio1: type 16550A
sio1: [FILTER]
fdc0: <floppy drive controller> port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on  
acpi0
fdc0: does not respond
device_attach: fdc0 attach returned 6
ppc0: <Parallel port> port 0x378-0x37f,0x778-0x77f irq 7 drq 3 on acpi0
ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode
ppc0: FIFO with 16/16/9 bytes threshold
ppbus0: <Parallel port bus> on ppc0
plip0: <PLIP network interface> on ppbus0
lpt0: <Printer> on ppbus0
lpt0: Interrupt-driven port
ppi0: <Parallel I/O> on ppbus0
ppc0: [GIANT-LOCKED]
ppc0: [ITHREAD]
fdc0: <floppy drive controller> port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on  
acpi0
fdc0: does not respond
device_attach: fdc0 attach returned 6
orm0: <ISA Option ROMs> at iomem 0xc0000-0xcafff,0xcb000-0xcbfff, 
0xcc000-0xccfff on isa0
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x300>
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on  
isa0
Timecounters tick every 1.000 msec
hptrr: no controller detected.
acd0: CDROM <CD-224E-N/1.AA> at ata0-master UDMA33
ad4: 157066MB <WDC WD1600YD-01NVB1 10.02E01> at ata2-master SATA150
ad5: 381553MB <WDC WD4000AAJS-00TKA0 12.01C01> at ata2-slave SATA150
ad6: 157066MB <WDC WD1600YD-01NVB1 10.02E01> at ata3-master SATA150
SMP: AP CPU #1 Launched!
Trying to mount root from ufs:/dev/ad4s1a
WARNING: ZFS is considered to be an experimental feature in FreeBSD.
ZFS filesystem version 6
ZFS storage pool version 6


KERNEL CONFIG is Generic with debug turned off and SCHED_ULE.

Could you please tell me where I am not right? Or what should I do to  
make it faster?

--
Alexey Tarasov

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