GeForce 256 Tweak Guide (Page 4/6)
Posted: March 7, 2000
Written by: Dan "Tweak Monkey" Kennedy
Registry Tweaks!
Before you mess around with these settings, a tweak should be applied that will enable all of the hidden options in the tweaking program. I didn't need to edit this value, but some people will probably need to. Open up regedit (Start, run, regedit), and navigate to HKEY_LOCAL_MACHINE\Software\NVIDIA Corporation\Global\NVTweak. Create a DWORD value called "CoolBits" and set its value to 3. Or you can download this file and run it. Double click the file and choose "Yes".
New Registry Tweaks
The following are the tweaks that were discovered since the original posting of this guide (thanks Nvidia!):
"EnableIrongate2x" - This registry string should enable AGP2X mode for AMD Athlon systems. If it works, this should increase performance. If it doesn't work, it may cause problems. The exact string for this value is:
[HKEY_LOCAL_MACHINE\Software\NVIDIA Corporation\Global\System]
"EnableIrongate2x"=dword:00000001
Either enter this string manually, or download this .reg file and run it. If you want to undo the settings, either download this file and run it, or delete the DWORD value specified above.
"ReqAGPFW" - This registry string should enable AGP Fast Writes. Fast Writes allow data to be transferred over the AGP bus with almost no latency, avoiding the system memory by sending data directly do the GeForce from the CPU (see page 8 of the GeForce 256 Preview for diagrams and info). However, this has yet to be used successfully by most people. If you want to try to use it, here's the value:
[HKEY_LOCAL_MACHINE\Software\NVIDIA Corporation\Global\System]
"ReqAGPFW"=dword:00000001
Enter this string manually, or download this .reg file and run it. If you want to undo the settings, either download this file and run it, or delete the DWORD value specified above.
"DoIOToFlushCache" - According to a Kevin Harris (thanks Kevin!), this will turn on the option to disable VSYNC. Since this is already part of the Nvidia display settings (or at least, it should be), you probably don't need it. If you do want to use it, here's the full string:
[HKEY_LOCAL_MACHINE\Software\NVIDIA Corporation\Global\System]
"DoIOToFlushCache"=dword:00000001
Download a .reg file here to enable it, or a .reg file here to disable it.
"ReqAGPRate" - To be honest, I still don't know what this does. "AGP rate" is what it looks like, but honestly, I couldn't find a practical purpose for this string. I tried it on my Pentium II system but I saw no improvements. Here's the full string:
[HKEY_LOCAL_MACHINE\Software\NVIDIA Corporation\Global\System]
"ReqAGPRate"=dword:00000001
Download a .reg file here to enable it or here to disable it.
"EnableIrongateSBA" - One other setting that recieved a lot of attention is EnableIrongateSBA. As the name suggests, this enables Irongate Sideband Addressing. As with the other "Irongate" setting, this appears to only work with Athlon systems. A lot of readers let me know that this tweak also only works with reference drivers v3.69+. Enable this setting for performance. It may possibly lead to problems, though. Here's the full string:
[HKEY_LOCAL_MACHINE\Software\NVIDIA Corporation\Global\System]
"EnableIrongateSBA"=dword:00000001
Download a .reg file here to enable, or download this .reg file to undo it if you have problems.
Remember, if any of the settings above give you problems, you can simply run the undo file or delete the DWORD value(s). Use the tweaks ONE AT A TIME (and test with games after each tweak) to avoid complications.
Display Settings
To access the display settings tweaks, right click your desktop and choose Properties. Click the Settings tab at the top, then the Advanced button. Click the GeForce tab at the top. It should display information about your video card.

