This guide is meant to help you control the fan speed of your Nvidia 8800gtx card. Please note that RivaTuner will work for most Nvidia and ATI cards. Furthermore, this guide was done using v2.02, but can be used for later releases.

If you are a owner of the 8800gtx you might have noticed the lack of fan support from Nvidia, (at the time this guide was written). The card's default speed is set on auto which has the fan stuck of 60% of its capacity, pretty much all the time. Considering today's demanding games, this card easily reaches temperatures of over 80°C. Therefore, to ensure longevity and better overclocking we recommend lowering those peak temperatures.

 To start of, download the latest version of RivaTuner. Once installed, configure RivaTuner to launch upon Windows startup.
Fig. 1 Next its time to create some fan speed profiles you might find suitable. Hit the customize button in the main tab under "Target Adapter" and then select low-level system setting represented by the left red circle in fig. 1. Once you're in the new window, under the "fan" tab hit enable low-level fan control, check "fixed" and then slide the cycle meter to your  preference, click apply and then hit the "floppy" icon to save your profile. We recommend to name it after the the fan cycle you chose, i.e. Fan65%. Also be sure to create several profiles, as it will allow you to create an automated threshold guide, where your card will utilize your fan speeds at designated temperatures. We recommend creating at least profiles at 60%, 65%, 80% & 90-100%. to do this simple move the slider, hit apply, save and use a different name for the new profile.

Once you've got your speed levels figured out it's time to make your fan presets available in
fig. 2the RivaTuner "Launcher". To
Regular item menu access the launcher click the "Launcher" tab in the RivaTuner main window.  To add your fan speeds hit the green plus icon  highlighted in fig. 2 and choose "regular item " when asked by the pop up window.  In the  "regular item menu"  start by naming your item, preferably after the same name you chose for you fan speed profile. Then check the "associated fan profile" box, choose the low-level option in the scroll-down menu and select one of your profiles, then hit OK. Follow these steps for each of the fan speeds you created a profile for. This will allow RivaTuner to easily launch your fan speeds by your command or when the card reaches a certain temp. threshold, which we will setup next.

 To setup the thresholds we need to access the Hardware Monitor which is found in the RivaTuner's main menu, (right red circle in fig. 1). Once in the hardware monitor make sure to enable
Monitoring Graphs"background monitoring". It's the "rec" looking icon in the bottom-left corner. Next right-click in the Core Temperature graph. This will bring up the Temp. monitoring setup where you'll click the green plus icon to add your thresholds. Start by giving your first threshold a name then set the value of your threshold. The card
Monitoring setup in our Fransa tech shop has an idle temperature of 65°C and a load temperature of 69°C to 82°C. We set our first threshold to 68°C to have the card kick in the fan as soon as we load a game. Next change the "launch" scroll down menu, from "application" to "item" and choose the fan profile you want to launch at 68 degrees, (we chose 80%). Also choose what fan profile you want once the temperature goes down under your ^o68 threshold, then hit OK. You can add more thresholds as needed, we also included a ^o80 threshold were the fan will go to 90% if temperatures would reach those heights.

ThresholdIf setup properly, your card fan will run slow and quite during low activity and kick into high gear during more demanding activity like gaming. Though establishing thresholds are useful, they are not necessary. You can easily change fan speed profiles from Rivatuner's launch pad prior to starting or after playing a game. Please note that Rivatuners "Hardware Monitoring" tool will consume resources and if you have non to spare you might want to launch the speed profiles manually. Happy gaming.

*EDIT* "per jack1614 in comments" We would like to mention that RivaTuner works on most cards, not only the 8800gtx. Compatibility list as follows:

• Any desktop display adapter based on NVIDIA NV4, NV5, NV10, NV11, NV15, NV17, NV18, NV20, NV25, NV28, NV30, NV31, NV34, NV35, NV36, NV38, NV40, NV41, NV44, NV44A, NV48, G70, G71, G72, G73 or G80 GPU or ATI R200, RV250, RV280, R300, RV350, R350, RV360, R360, RV370, RV380, R420, RV410, R423, R430, R480, RV515, R520, RV530, RV560, RV570, R580 or R580+ VPU based display adapter.

• Detonator 2.08 or higher NVIDIA reference drivers for Windows 98 / Windows 98 SE or Windows ME.

• Detonator 5.08 or higher NVIDIA reference drivers for Windows 2000 / Windows XP.
  

The reason we emphasized the 8800 card was due to its legendary lack of fan support.