terrible mplayer performance

[Neil Short]

Ok. I'm stuck. Mplayer's performance is worse on this laptop than it is on my Toshiba running with a half-speed processor. I have attempted all the suggestions I can find re: getting the performance.
The video is slow - so it lags the audio by quite a bit. I keep getting "Your processor is too slow..." stuff.

What to do?

I built mplayer from ports (not package).
mplayer-1.0.r20100117_1

My computer is an HP Pavilion dv4

xorg.conf is set up to run the vesa driver. That's how X -configure set it up. I have no idea what graphics device is actually on this machine.

dmesg shows:
Copyright (c) 1992-2010 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 8.1-PRERELEASE #1: Mon Jun  7 10:53:01 MST 2010
    neshort at carmen:/usr/obj/usr/src/sys/CARMEN amd64
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Core(TM) i3 CPU       M 330  @ 2.13GHz (2127.92-MHz K8-class CPU)
  Origin = "GenuineIntel"  Id = 0x20652  Family = 6  Model = 25  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=0x98e3bd<SSE3,DTES64,MON,DS_CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT>
  AMD Features=0x28000800<SYSCALL,RDTSCP,LM>
  AMD Features2=0x1<LAHF>
  TSC: P-state invariant
real memory  = 4294967296 (4096 MB)
avail memory = 3892748288 (3712 MB)
ACPI APIC Table: <HPQOEM SLIC-MPC>
FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
FreeBSD/SMP: 1 package(s) x 2 core(s) x 2 SMT threads
 cpu0 (BSP): APIC ID:  0
 cpu1 (AP): APIC ID:  1
 cpu2 (AP): APIC ID:  4
 cpu3 (AP): APIC ID:  5
...
vgapci0: <VGA-compatible display> port 0x6050-0x6057 mem 0xd0000000-0xd03fffff,0xc0000000-0xcfffffff irq 16 at device 2.0 on pci0
agp0: <Intel Ironlake (M) SVGA controller> on vgapci0
agp0: detected 32764k stolen memory
agp0: aperture size is 256M
...
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