A Month and half ago I decided I wanted to dabble in the SLI front from Nvidia. I had read alot of things and decided I wanted to give it a try. My initial impressions were posted in this thread
where I discussed the pros and cons of SLI. Things have come along way since then and profiles could never be easier to setup. If you're not satisfied with setting up profiles you are now also able to globally force SLI in the control panel providing you have the Coolbits Tweak
installed on your system.
Downloading and Installing coolbits. Coolbits can be downloaded several places but you can get here
as well. After downloading coolbits2.reg you'll want to right click the file and merge it into your registry.
At this point all you have to do is enter your control panel and globally force SLI in either Split Frame Rendering, Alternative Frame Rendering, or Single GPU Rendering. You can access these modes by selecting the "Show Advanced Settings" in the control panel.
Setting up your SLI Profile within the drivers. The advantage of setting an SLI profile is that when you find your desired SLI rendering mode you are able to save it and the Nvidia drivers will forever pick up on it and automatically overwrite any global driver settings you have. This is exceedingly useful and convenient when dealing with SLI making it a one time setup for individual games that do not support SLI by default
Play on! Once you have your SLI rendering method setup in either a global driver setting or SLI profile you will be able to play games with SLI enabled. Quite an improvement since my last article
showing that Nvidia has been taking the steps to make SLI easier to use for everyone. One thing to note is if the SLI profile is already activated by default you cant change it within the control panel. I still advise editing the nvapps.xml and removing the "predefined" tag for SLI profiles that Nvidia has set and you wish to change manually. The other option is to use Nhancer
which will also allow you to manipulate predefined SLI settings.
If Nvidia has a custom SLI profile for a certain app. Its probably best to leave it alone. Many SLI apps specified by Nvidia have specific compatibility bits which either improve performance or compatibility
Check out the load balancer in the SLI panel of the Nvidia Drivers. It will allow you to see how each game is being loaded on each GPU
If SLI doesnt not seem to be helping your performance. Try turning up the graphic resolution or anti aliasing settings. In many cases you are CPU limited and you can get away with quality settings for free with SLI.