A single GeForce 6600 GT is quite a solid value for the money. In spite of its 128 MB of onboard memory and 128-bit memory interface, the card is proving itself very capable of running games at resolutions upward of 1280x1024. Some titles can even run with anti-aliasing (AA) and anisotropic filtering (AF) at these resolutions. Adding a second card for SLI support should theoretically be the proverbial icing on the cake. As most 6600 GT cards cost less than $200, getting a pair of them won't put a tremendous strain on an enthusiastís budget.
The system that will be putting this MSI 6600 GT SLI duo to the test includes:
NVIDIA nForce drivers (v6.39) and ForceWare video drivers (v71.81)
All in Place
The photo shows my old hard drive setup of two Western Digital parallel ATA units. After my benchmarking was completed, I upgraded to a pair of Western Digital Raptor drives running in RAID-0. It doesn't help game performance at all, but it makes level loading times a lot shorter.
FORCEWARE DRIVERS AND SLI SOFTWARE
Since my purchase of the 6600 GT, there have been at least a half dozen different NVIDIA ForceWare driver sets leaked by either manufacturers or in-house developers. On top of that, some enterprising end users have been modifying these sets to provide additional performance and/or quality improvements. With so many different drivers available, it can be hard to find a single set to use for testing and everyday use. After trying an assortment of different versions, I settled on 71.81 for this test. Performance and image quality on my system were both quite good, and the number of SLI-supported game titles was impressive as well.
71.81 Control Panel
NVIDIA uses a profile system to enable SLI and adjust image quality settings. I'll say this up front: the current system employed is, at best, cumbersome to use. Further, not all settings I tried to employ stuck for a particular profile. While I hope NVIDIA is working on a better way to deploy this feature, some users have taken matters into their own hands.
NVSLI APPLICATION OPTIMIZER
This is a little application available from 3DChipset.com that allows you to directly edit the nvapps.xml file where game profiles are stored. You can specify the SLI mode a particular game can use: single GPU rendering, alternate-frame rendering (AFR) or split-frame rendering (SFR). Keep in mind, the built-in profiles have pre-defined SLI modes which are tested by NVIDIA to provide optimal performance.
NvSLI Application Optimizer
As always, there can be exceptions to the rules. Those I will get into in the performance test for one particular game. This application I found to be very handy for forcing this game to use single GPU rendering, as the pre-defined AFR profile resulted in worse performance. The numbers will tell the story on the next page.
This application has fast become my favorite, not just for SLI adjustment, but for adjusting image quality settings within each game. You can read more about this program and download it via the nV News forums.
The screenshot above is from a beta version I am testing. It includes several enhancements and bug fixes from the current release. The final release of version 1.1 should be available about at about the time you're reading this.
If you have an SLI setup, I highly recommend downloading both of these program. They will go a long way in helping you achieve optimal settings for all your games without having to mess with the NVIDIA's profile system. The time and headaches you will save are well worth it. Now onto the tests!