Obtaining a Lower CPU usage - Joomla! Forum - community, help and support

hello. website has been getting cpu usage amount on server , don't know problem is. maybe because bridged joomla coppermine. suspect might caused opensef.  but, however, think caused .htaccess file. example, if type in http://www.mywebsite.com/adfadfad, page, doesn't exist, take 1 or 2 minutes load 404 "page not found" page. not know why takes long. here's copy of .htaccess:


# @version $id: htaccess.txt 4085 2006-06-21 16:03:54z stingrey $
# @package joomla
# @copyright copyright (c) 2005 open source matters. rights reserved.
# @license http://www.gnu.org/copyleft/gpl.html gnu/gpl
# joomla! free software
##


#####################################################
#  read if choose use file
#
# line below section: 'options followsymlinks' may cause problems
# server configurations.  required use of mod_rewrite, may already
# set server administrator in way dissallows changing in
# .htaccess file.  if using causes server error out, comment out (add #
# beginning of line), reload site in browser , test sef url's.  if work,
# has been set server administrator , not need set here.
#
# use 1 of 2 sef sections follow.  lines can uncommented
# (and used) have 1 #.  lines 2 #'s should not uncommented
# in section don't use, lines should start #
#
# standard sef, use standard sef section.  can comment out
# of rewritecond lines , reduce server's load if you
# don't have directories in root named 'component' or 'content'
#
# if using 3rd party sef or core sef solution
# uncomment of lines in '3rd party or core sef' section
#
#####################################################
#
#####  solving problems component url's don't work #####
# special note smf users when smf integrated , bridged
# or situation component's url's aren't working
#
# in both 'standard sef', , '3rd party or core sef' sections line:
# rewritecond %{request_uri} ^(/component/option,com) [nc,or] ##optional - see notes##
# may need uncommented.  if running joomla/mambo from
# subdirectory name of subdirectory need inserted this
# line.  example, if joomla/mambo in subdirectory called '/test/',
# change this:
# rewritecond %{request_uri} ^(/component/option,com) [nc,or] ##optional - see notes##
# this:
# rewritecond %{request_uri} ^(/test/component/option,com) [nc,or] ##optional - see notes##
#
#####################################################
#
#
##  can commented out if causes errors, see notes above.
#options followsymlinks


#  mod_rewrite in use
#
rewriteengine on
#

#  uncomment following line if webserver's url
#  not directly related physical file paths.
#  update joomla/mambodirectory (just / root)
#
# rewritebase /
#

########## begin - joomla! core sef section
############# use section if using joomla! core sef
## (rewritecond) lines in section required if actually
## have directories named 'content' or 'component' on server
## if not have directories these names, comment them out.
#
#rewritecond %{request_filename} !-f
#rewritecond %{request_filename} !-d
#rewritecond %{request_uri} ^(/component/option,com) [nc,or] ##optional - see notes##
#rewritecond %{request_uri} (/|\.htm|\.php|\.html|/[^.]*)$  [nc]
#rewriterule ^(content/|component/) index.php
#
########## end - joomla! core sef section
#
#
#
########## begin - 3rd party sef section
############# use section if using 3rd party (non joomla! core) sef extension - e.g. opensef, 404_sef, 404sefx, sef advance, etc
#
#rewritecond %{request_uri} ^(/component/option,com) [nc,or] ##optional - see notes##
rewritecond %{request_uri} (/|\.htm|\.php|\.html|/[^.]*)$  [nc]
rewritecond %{request_filename} !-f
rewritecond %{request_filename} !-d
rewriterule (.*) index.php
deny 88.203.210.121
deny 88.203.210.xxx
#
########## end - 3rd party sef section

please me problem. website has been taken offline several times because of high cpu usage , don't know do. hope posted in right forum. sorry if didn't.  please me, thank much.

most opensef. try switch off , access non-existant url.