There are many reasons for framerate and/or stuttering issues with dual core. The patches and fixes suggested here should help alleviate any issues you are having.

Nivida Dual Core Optimised Drivers (81.84 to 82.12)
Windows XP and Dual Core
AMD X2 Dual Core Driver
Intel Dual Core Patch

Please note that these changes should only be applied if you have a dual core system and are experiencing framerate and/or stuttering issues with r_useSMP enabled.

Nivida Dual Core Optimised Drivers (81.84 to 82.12)
Nvidia driver revisions 81.84 to 82.12 can cause framerate and stuttering issues with games that are dual core optimised. To address this problem in Quake 4 we have created a registry file that disables dual core enhancements in Nvidia Forceware 81.84 to 82.12. 

Follow the instructions carefully. We are not responsible for any problems caused by editing the registry.


1. Download the UC_DualCoreNvidia.reg registry file and open it in NotePad for editing


2. Load RegEdit (Start | Run | RegEdit ) and determine the current primary display card by looking in Hkey_Local_Machine\Hardware\DeviceMap\Video and noting down the GUID (global unique identifier assigned by Windows) for the entry \device\video0, this is the long string at the end of the entry in brackets { }.

3. Edit the lines in the UC_DualCoreNvidia.reg file that read  
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video\{YOUR_GUID_HERE}\0000 so that {YOUR_GUID_HERE} contains your GUID from step 2. 

For example, if your GUID is 76CD7216-2725-4175-BD7A-971674F7919C the modified lines would be 
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video\{76CD7216-2725-4175-BD7A-971674F7919C}\0000]
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video\{76CD7216-2725-4175-BD7A-971674F7919C}\0000\OGL_ThreadControl]


4. Save the UC_DualCoreNvidia.reg file with the GUID change made in step 3 and double click on it to enter the changes into your registry.


5. Reboot your machine, you may need execute the edited UC_DualCoreNvidia.reg again in case the registry changes have been reset




Windows XP and Dual Core
WindowsXP has a documented problem with Dual Core and power saving for AMD X2 processors in service pack 2. This can easily be worked around with installation of a hotfix and a registry change. Follow the instructions carefully. We are not responsible for any problems caused by editing the registry.


1. Download the UC_XP_KB896256.reg file 

2. Download and install the Windows XP Hotfix detailed in knowledge base entry KB896256. We cannot provide a link to the fix here, we suggest you search on Google

3. Double click on the UC_XP_KB896256.reg file to enter the changes into your registry.

4. Reboot your machine, repeat step 3 in case the registry changes have been reset

Note: This has only been tested on an AMD X2 Dual Core System.




AMD X2 Dual Core Driver
It is important that all AMD X2 users download and install the AMD Athlon™ 64 X2 Dual Core Processor Driver for their operating system. This driver addresses timing issues with many applications and will help stop crashes and address stuttering / frame rate issues in games.




Intel Dual Core Patch
This addresses timing issues with many applications and will help stop crashes and address stuttering / frame rate issues in games.

1. Right click on My Computer, and select Properties.

2. Select the Advanced tab, and click Settings under Startup and Recovery.

3. Click Edit under System Startup and open Notepad.
Add /usepmtimer to the end of the [operating systems] section. For example

[operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect /usepmtimer

4. Save the BOOT.INI file and close Notepad.

5. Reboot your system