I am having problems with rviz. When I have a robot model loaded (many
difference models such as pr2, p2os, or others), a point cloud (such
as from stereo_image_proc), or a costmap displayed, the update rate of
rviz goes way down. Also all GUI response time (moving windows,
dragging windows, etc) starts lagging quite a bit. Looking at top,
rviz is not taking up a lot of CPU, but Xorg goes to 100% as soon as
rviz is started. I have noticed that maximizing/unmaximizing the
window sometimes helps the problem, but will also frequently crash
rviz as well. I have noticed that turning twinview off will fix the
problem temporarily, but then will come back after a while. Turning
twinview back on will sometimes fix the problem or sometimes crash
rviz. These problems do NOT happen in the boxturtle version of rviz. I
am running the most recent version of ROS -r10792 and rviz -r31988
from SVN on a machine that is a well-updated version of Ubuntu 10.04.
Any ideas?

my graphics card:

01:00.0 VGA compatible controller: nVidia Corporation G84 [Quadro FX
570] (rev a1)
	Subsystem: nVidia Corporation Device 0474
	Flags: bus master, fast devsel, latency 0, IRQ 16
	Memory at fc000000 (32-bit, non-prefetchable) [size=16M]
	Memory at d0000000 (64-bit, prefetchable) [size=256M]
	Memory at fa000000 (64-bit, non-prefetchable) [size=32M]
	I/O ports at dc80 [size=128]
	[virtual] Expansion ROM at fde00000 [disabled] [size=128K]
	Capabilities: <access denied>
	Kernel driver in use: nvidia
	Kernel modules: nvidia-current, nvidiafb, nouveau


my CPU:

processor	: 3
vendor_id	: GenuineIntel
cpu family	: 6
model		: 15
model name	: Intel(R) Core(TM)2 Quad CPU    Q6600  @ 2.40GHz
stepping	: 11
cpu MHz		: 2393.567
cache size	: 4096 KB
physical id	: 0
siblings	: 4
core id		: 3
cpu cores	: 4
apicid		: 3
initial apicid	: 3
fpu		: yes
fpu_exception	: yes
cpuid level	: 10
wp		: yes
flags		: 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 ht tm pbe syscall nx
lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni dtes64
monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm tpr_shadow
vnmi flexpriority
bogomips	: 4787.98
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management: