We recently upgraded all of our desktops in our department, and I loaded Centos 5.3 on them. We are experiencing very slow performance when using firefox, thunderbird, or any graphical applications. We tried using ATI as well as NVidia video cards, as well as their respective drivers with no change in performance. Sometimes it will lock up for 3-5 secs while typing and show up later. It was an annoyance at first, but now it is a real productivity drain. I can't even begin to think of how to diagnose this as there are no real errors. The only odd thing is that sometimes Xorg seems to be running as root and using 18% cpu. I suspect this is the problem, but I don't know why it is doing this. There is nothing in the Xorg.0.log of any interest.

Here is my hardware/software:
Centos 5.3
2.6.18-164.el5PAE
Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz
MemTotal: 8177512 kB
MemFree: 7076740 kB
Firefox/3.0.15

Hi,
It sounds like you have a problem with the ati/nvidia drivers. It would be helpful to post more info such as an xorg.conf file. Also #lsmod.

I have used nv, nvidia, and vesa drivers with the same results. It looks like a problem with Xorg. I have seen some posts of high cpu usage with xorg, but no solutions. If i click and drag a window, it spikes to 90% cpu usage with nothing else on! I updated to Centos 5.4 and the 190 Nvidia driver with no change in performance. I'll post my xorg.conf for anyone to poke at:

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 1.0 (buildmeister@builder63) Tue Oct 20 21:00:15 PDT 2009

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 1.0 (buildmeister@builder63) Fri Aug 14 17:55:55 PDT 2009
# Xorg configuration created by system-config-display

Section "ServerLayout"
Identifier "single head configuration"
Screen 0 "Screen0" 0 0
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
EndSection

Section "ServerFlags"
Option "Xinerama" "0"
EndSection

Section "InputDevice"

# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/input/mice"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
Option "XkbModel" "pc105"
Option "XkbLayout" "us"
EndSection

Section "Monitor"

### Comment all HorizSync and VertSync values to use DDC:
Identifier "Monitor0"
VendorName "Unknown"
ModelName "DELL G2210"
HorizSync 30.0 - 83.0
VertRefresh 56.0 - 76.0
Option "DPMS"
EndSection

Section "Monitor"
Identifier "Monitor1"
VendorName "Unknown"
ModelName "DELL 2005FPW"
HorizSync 30.0 - 83.0
VertRefresh 56.0 - 75.0
EndSection

Section "Device"
Identifier "Videocard0"
Driver "nvidia"
EndSection

Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce 9300 GE"
EndSection

Section "Device"
Identifier "Device1"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce 9300 GE"
BusID "PCI:1:0:0"
Screen 1
EndSection

Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "TwinView" "0"
Option "metamodes" "DFP-0: nvidia-auto-select +0+0"
SubSection "Display"
Depth 24
EndSubSection
EndSection

Section "Screen"
Identifier "Screen1"
Device "Device1"
Monitor "Monitor1"
DefaultDepth 24
Option "TwinView" "0"
Option "metamodes" "DFP-1: nvidia-auto-select +0+0"
SubSection "Display"
Depth 24
EndSubSection
EndSection



#lsmod:
Module Size Used by
nfsd 204337 17
exportfs 9665 1 nfsd
auth_rpcgss 43105 1 nfsd
autofs4 29253 2
hidp 23105 2
l2cap 29505 5 hidp
bluetooth 53925 2 hidp,l2cap
nfs 229697 2
fscache 20321 1 nfs
nfs_acl 7617 2 nfsd,nfs
lockd 63081 3 nfsd,nfs
sunrpc 145533 22 nfsd,auth_rpcgss,nfs,nfs_acl,lockd
ip_conntrack_netbios_ns 6977 0
iptable_nat 11077 0
ip_nat 21101 1 iptable_nat
iptable_mangle 6849 0
ipt_LOG 10049 3
xt_state 6209 2
ip_conntrack 53281 4 ip_conntrack_netbios_ns,iptable_nat,ip_nat,xt_state
nfnetlink 10713 2 ip_nat,ip_conntrack
iptable_filter 7105 1
ip_tables 17029 3 iptable_nat,iptable_mangle,iptable_filter
ip6t_REJECT 9409 1
xt_tcpudp 7105 7
ip6table_filter 6849 1
ip6_tables 18053 1 ip6table_filter
x_tables 17349 7 iptable_nat,ipt_LOG,xt_state,ip_tables,ip6t_REJECT,xt_tcpudp,ip6_tables
dm_mirror 24393 0
dm_multipath 24909 0
scsi_dh 11713 1 dm_multipath
video 21192 0
hwmon 7365 0
backlight 10049 1 video
sbs 18533 0
i2c_ec 9025 1 sbs
button 10705 0
battery 13637 0
asus_acpi 19289 0
ac 9157 0
ipv6 267489 17 ip6t_REJECT
xfrm_nalgo 13381 1 ipv6
crypto_api 12609 1 xfrm_nalgo
lp 15849 0
snd_hda_intel 427281 2
sr_mod 19941 0
cdrom 36577 1 sr_mod
snd_seq_dummy 7877 0
snd_seq_oss 32577 0
snd_seq_midi_event 11073 1 snd_seq_oss
snd_seq 49585 5 snd_seq_dummy,snd_seq_oss,snd_seq_midi_event
snd_seq_device 11725 3 snd_seq_dummy,snd_seq_oss,snd_seq
snd_pcm_oss 42817 0
nvidia 8880740 28
snd_mixer_oss 19009 1 snd_pcm_oss
e1000e 113049 0
snd_pcm 72261 3 snd_hda_intel,snd_pcm_oss
parport_pc 29157 1
i2c_i801 11725 0
sg 36573 0
pcspkr 7105 0
parport 37513 2 lp,parport_pc
i2c_core 23745 3 i2c_ec,nvidia,i2c_i801
snd_timer 24517 3 snd_seq,snd_pcm
snd_page_alloc 14281 2 snd_hda_intel,snd_pcm
snd_hwdep 12869 1 snd_hda_intel
snd 55749 11 snd_hda_intel,snd_seq_oss,snd_seq,snd_seq_device,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer,snd_hwd ep
soundcore 11553 1 snd
serio_raw 10693 0
dm_raid45 67145 0
dm_message 6977 1 dm_raid45
dm_region_hash 15681 1 dm_raid45
dm_log 14657 3 dm_mirror,dm_raid45,dm_region_hash
dm_mod 63225 4 dm_mirror,dm_multipath,dm_raid45,dm_log
dm_mem_cache 9537 1 dm_raid45
ahci 35017 4
libata 157445 1 ahci
sd_mod 25281 6
scsi_mod 141717 5 scsi_dh,sr_mod,sg,libata,sd_mod
ext3 125001 3
jbd 57065 1 ext3
uhci_hcd 25549 0
ohci_hcd 24809 0
ehci_hcd 34125 0