I typed this up last night to help out my friends.  I am reposting here for your information.  Here is a link to the original, followed by the full text of my post:

http://lockedbox.guildomatic.com/forums/viewtopic.php?f=2&t=6

We are going to change your configuration.  Make sure you back up your configuration in case any of these fixes have unforeseen consequences outside of the scope of this article.  There are a few simple changes we need to make to the configuration file of COD:BO in order for it to work optimally for a PC.  My guess is that the game was written for XBOX360 first then ported to PC, and they didn't bother to change the configuration settings to reflect this shift in format.  At the end, I have some more recommendations for easing the graphics load on a crappy video card, port forwarding your router to make sure the connections aren't blocked, and running your PC optimally to make sure the Windows operating system won't interfere with your gameplay.

The first problem is that the default config assumes you are running multiple GPU cores on a single CPU.  For most people, this is the other way around (multi-core CPU with a single-core GPU).  Here is the fix:

1) Navigate to c:\Program Files\Steam\SteamApps\Common\Call of Duty Black Ops\Players
(If you are on 64-bit windows, you will be looking for \Program Files (x86)\)
2) Open config_mp.cfg in Notepad or Wordpad (I reccomend navigating to this file from notepad's "Open" dialogue, making sure to change the dropdown from "Open *.txt files" to "Open all files *.*")
3) ctrl+F to open the "Find" dialogue
4) Search for "r_multiGpu"
5) If r_multiGpu is set to 1, change it to 0, unless you have multiple GPU's
6) Search for r_multithreaded_device
7) If r_multithreaded_device is set to 0, change it to 1, unless you have a single core processor

The setting cl_maxpackets dictates how many updates your client will send to the server.  The more information you send per second, the more your moves will register on an opponent's screen, and the less you will shoot somebody to later find out that, according to the server, they actually shot you first.  Here's how to fix that:

1) Search for cl_maxpackets
2) Set cl_maxpackets to 100
3) If cl_maxpackets does not exist, enter this string at the end of the config:
seta cl_maxpackets "100"

Along the lines of cl_maxpackets, sv_maxrate dictates how many times per second the server will update you with information.  You will want to turn this as high as possible, so what you are seeing on the screen is actually what is happening on the server, rather than your milliseconds-old version of events.  Here's the fix:

1) Search for sv_maxrate
2) Set sv_maxrate to 25000
3) If sv_maxrate does not exist, enter this string at the end of the config:
seta sv_maxrate "25000"

Now, we need to make our changes permanent.  Doing this will lock your configuration, and we need to do this so COD:BO or Steam don't overwrite our changes and make for a very frustrated tweaker.  Here's how we do it:

1) Save and close config_mp.cfg
4) Right click the config_mp.cfg file and select "Properties".
5) Check "Read Only"
NOTE:  If you need to change any settings, any button binds, video settings, sound settings, clan tag,etc. ad nauseum, you will need to unlock your configuration file as this information is stored in the configuration file that we just made "Read only".  THIS DOES NOT EFFECT CLASSES, KILLSTREAKS, OR CONTRACTS AS THESE ARE NOW HANDLED SERVER-SIDE.

The last permanent fix is actually in your registry (WINDOWS VISTA AND WINDOWS 7 ONLY).  The registry has a setting that limits the amount of outbound packets being sent at any one time, obviously conflicting with your choice to send as many packets as you can to the server to register your actions faster and result in more millisecond-twitch kills.  Vista/7 caps network traffic at 10 packets per second, which is much lower than the 100 we desire from cl_maxpackets.  Here's how to remove that cap:

1) Hold the windows key and press the " r " key.  This will bring up a run dialogue
2) Type "regedit.exe" in to the run dialogue, and open up the registry editing program by pressing "run" or hitting "enter"
3) Navigate through the folders to this address:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile\
4) Right click on the file "NetworkThrottlingIndex"
5) Change the value from 10 (or whatever it currently is) to "FFFFFFFF" in hexadecimal
6) Restart your computer

PRO-TIPS
*Close every application and install new graphics card drivers.
*In your graphics card configuration, set all settings to MAXIUMUM (not the in-game settings, but NVidia/ATI/AMD/etc's settings)
NOTE:  A lot of cards don't have any settings like this, don't worry.
*Close COD:BO and open Steam.  Navigate to Games/Library.  Right click COD:BO.  Deselect the following:
Enable Steam Community In-Game
Always keep this game up to date
Enable Steam Cloud sync
Now select "Verify integrity of game cache"
Now select "Defragment cache files"
*Forward your ports if you're behind a router: TCP [3074] UDP [3074] (http://www.portforwarding.com for more information)
*Install and use GameBooster http://www.iobit.com/gamebooster.html

ADDITIONAL PRO-TIPS (reduce graphics to boost FPS)
Only try these after everything else has proven not to work because the game will look like shit:
r_blur_allowed 0
r_distortion 0
r_dof_enable 0
r_glow_allowed 0
cg_brass 0
r_cachemodellighting 1

Compiled by Michael Kilgore.
makilgore06@GOOGLE'S EMAIL DOMAIN.com
facebook.com/makilgore06

Originally posted to:
http://lockedbox.guildomatic.com/

By default, the value for the NetworkThrottlingIndex registry entry is set to 10. When the NetworkThrottlingIndex registry entry does not exist, the behavior resembles the default behavior. Network throttling can be completely turned off by setting the value to FFFFFFFF (hexadecimal). You must restart the computer after you make a change to the value of the NetworkThrottlingIndex registry entry.

Bump